Grain

Grading

Primer

Marketing and

Regulatory

Programs

Agricultural

Marketing

Service

Federal Grain

Inspection

Service

Washington, D.C.

October 2016
Grain Grading Primer

Foreword

The effectiveness of the U.S. grain inspection system depends largely on an inspector’s ability to 

sample, inspect, grade, and certify the various grains for which standards have been established 

under the United States Grain Standards Act, as amended. This publication is designed primarily 

to provide information and instruction for producers, grain handlers, and students on how grain is 

graded. It is not designed for Official grain inspectors for they must necessarily use more detailed 

instruction than that provided herein. In view of this fact, the Federal Grain Inspection Service, 

published the Grain Inspection Handbook, Book II, Grain Grading Procedures, which documents 

the step-by-step procedures needed to effectively and efficiently inspect grain in accordance with 

the Official United States Standards for Grain.

The mention of firm names or trade products does not imply that they are endorsed or 

recommended by the United States Department of Agriculture over other firms or similar approved 

products not mentioned.

United States Department of Agriculture

Agricultural Marketing Service

Federal Grain Inspection Service

Informational Reference October 2016

The U.S. Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of 

race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status. 

(Not all prohibited bases apply to all programs.) Persons with disabilities who require alternate means 

for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s 

TARGET Center at (202) 720-2600 (voice and TDD).

To file a complaint, write to the USDA, Office of Civil Rights, Room 326-W, 1400 Independence Avenue, 

SW, Washington, DC 20250-9410, or call (202) 720-5964 (voice and TDD). USDA is an equal employment 

opportunity employer.

Foreword

Table of Contents
Table of Contents

1 BARLEY page 4 

2 CANOLA page 37

3 CORN page 59

4 FLAXSEED page 85

5 OATS page 104 

6 RYE page 133

7 SORGHUM page 159

8 SOYBEANS page 188

9 SUNFLOWER SEED page 215

10 WHEAT page 243
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Chapter 1: Barley 

Grain Grading Primer

Chapter 1

Barley
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October 2016

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Contents

Chapter 1: Barley 

Barley Definition .....................................................................................................................4

Class........................................................................................................................................4

Malting Barley .........................................................................................................................4

Grade Requirements .............................................................................................................5

Sample Grade .........................................................................................................................7

Heating ....................................................................................................................................7

Distinctly Low Quality ............................................................................................................8

Special Grades........................................................................................................................8

Processing the Original Sample ...........................................................................................9

Boerner Divider.....................................................................................................................10

File Sample............................................................................................................................ 11

Use Moisture Proof Containers ........................................................................................... 11

Moisture .................................................................................................................................12

Check for Sample Grade ......................................................................................................13

Check for Garlic ....................................................................................................................13

Dockage.................................................................................................................................14

Mechanical Cleaning ............................................................................................................14

Rescreening ..........................................................................................................................15

Check for Insects..................................................................................................................15

Live Weevils ..........................................................................................................................16

Other Live Insects ................................................................................................................16

Check Odor ...........................................................................................................................16

Check for Stones ..................................................................................................................17

Test Weight per Bushel .......................................................................................................17

Processing the Work Sample ..............................................................................................18

Check for Smut .....................................................................................................................19

Check for Ergot .....................................................................................................................19

Determine Thin Barley .........................................................................................................19

Determine Plump Barley ......................................................................................................20
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Sieving Procedure ...............................................................................................................20

Determine Class & Subclass ...............................................................................................21

Damaged Kernels .................................................................................................................22

Visual Reference Images .....................................................................................................22

Blight-Damaged ...................................................................................................................23

Mold-Damaged ......................................................................................................................23

Frost-Damaged Kernels .......................................................................................................23

Germ-Damaged (Sick / Mold)...............................................................................................24

Heat-Damaged ......................................................................................................................24

Weevil or Insect-Bored .........................................................................................................25

Sprout-Damaged ...................................................................................................................25

Check for Blighted Barley....................................................................................................25

Malting Factors .....................................................................................................................26

Injured-by-Heat .....................................................................................................................26

Injured-by-Frost ....................................................................................................................27

Injured-by-Mold .....................................................................................................................27

Kernel Texture .......................................................................................................................27

Barley Pearler Procedure.....................................................................................................28

Standardizing the Pearler ....................................................................................................29

Foreign Material ....................................................................................................................29

Wild Oats...............................................................................................................................30

Other Grains..........................................................................................................................30

Sound Barley ........................................................................................................................30

Skinned and Broken Kernels...............................................................................................31

Broken Kernels .....................................................................................................................31

Other Official Criteria ...........................................................................................................31

Injured-by-Sprout .................................................................................................................32

Determine Grade Designation .............................................................................................32

Documenting the Grade .......................................................................................................33
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Barley Definition

Barley is defined as grain that, before the removal of dockage, consists of 50 percent or more 

of whole kernels of cultivated barley and not more than 25 percent of other grains for which 

standards have been established under the United States Grain Standards Act. 

The term “barley” as used in these standards shall not include hull-less barley or black barley.

Class

Barley is divided into two classes: Malting barley and Barley. 

To meet the requirements for Malting barley, barley may not be infested, blighted, ergoty, 

garlicky, smutty, or contain any special grades.

Malting Barley

Malting barley is divided into three subclasses: Six-rowed Malting barley, Six-rowed Blue 

Malting barley, and Two-rowed Malting barley.

The subclass Six-rowed Malting Barley is barley that has a minimum of 95.0 percent of a 

six-rowed suitable malting type that has 90.0 percent or more of kernels with white aleurone 

layers that contains not more than 1.9 percent injured-by-frost kernels, 0.4 percent frostdamaged kernels, 0.2 percent injured-by-heat kernels, and 0.1 percent heat-damaged 

kernels. Six-rowed Malting barley shall not be infested, blighted, ergoty, garlicky, or smutty.
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The subclass Six-rowed Blue Malting Barley is barley that has a minimum of 95.0 percent 

of a six-rowed suitable malting type that has 90.0 percent or more of kernels with blue 

aleurone layers that contains not more than 1.9 percent injured-by-frost kernels, 0.4 percent 

frost-damaged kernels, 0.2 percent injured-by-heat kernels, and 0.1 percent heat-damaged 

kernels. Six-rowed Blue Malting barley shall not be infested, blighted, ergoty, garlicky, or 

smutty.

The subclass Two-rowed Malting Barley is barley that has a minimum of 95.0 percent of 

a two-rowed suitable malting type that contains not more than 1.9 percent injured-by-frost 

kernels, 0.4 percent frost-damaged kernels, 0.2 percent injured-by-heat kernels, 0.1 percent 

heat-damaged kernels, 1.9 percent injured-by-mold kernels, and 0.4 percent mold-damaged 

kernels. Two-rowed Malting barley shall not be infested, blighted, ergoty, garlicky, or smutty.

Grade Requirements 

Six-rowed Malting and Six-rowed Blue Malting barley are divided into four numerical grades. 

The factors affecting the numerical grade include: test weight per bushel, suitable malting 

type, sound barley, damaged kernels total, foreign material, Other grains, skinned and broken 

kernels, and thin barley.

Six-rowed Malting and Six-rowed Blue Malting barley that does not meet the requirements for 

U.S. Nos. 1, 2, 3, or 4 Malting are graded under the Barley standards.

Six-rowed Malting Barley Grade Requirements

SIX-ROWED MALTING BARLEY AND SIX-ROWED BLUE MALTING BARLEY

Grade

 Minimum Limits of - Maximum Limits of -

Test 

weight per 

bushel 

(pounds)

Suitable 

malting 

type 

(percent)

Sound 

barley1

(percent)

Damaged 

kernels1

(percent)

Foreign 

material

(percent)

Other 

grains 

(percent)

Skinned 

broken 

kernels 

(percent)

Thin

barley*

(percent)

U.S. No. 1 47.0 95.0 97.0 2.0 0.5 2.0 4.0 7.0

U.S. No. 2 45.0 95.0 94.0 3.0 1.0 3.0 6.0 10.0

U.S. No. 3 43.0 95.0 90.0 4.0 2.0 5.0 8.0 15.0

U.S. No. 4 43.0 95.0 87.0 5.0 3.0 5.0 10.0 15.0

The applicant may request that Malting barley varieties be inspected and graded in 

accordance with the standards established for the class Barley even though the lot would 

qualify as Malting Barley.
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Two-rowed Malting barley is also divided into four numerical grades. 

The factors affecting the numerical grade include: test weight per bushel, suitable malting 

types, sound barley, wild oats, foreign material, skinned and broken kernels, and thin barley.

Two-rowed Malting Barley Grade Requirements

TWO-ROWED MALTING BARLEY

Grade

 Minimum Limits of - Maximum Limits of -

Test 

weight per 

bushel 

(pounds)

Suitable 

malting 

type 

(percent)

Sound 

barley1

(percent)

Wild

Oats

(percent)

Foreign 

material

(percent)

Skinned 

broken 

kernels 

(percent)

Thin

barley*

(percent)

U.S. No. 1 50.0 97.0 98.0 1.0 0.5 5.0 5.0

U.S. No. 2 48.0 97.0 98.0 1.0 1.0 7.0 7.0

U.S. No. 3 48.0 95.0 96.0 2.0 2.0 10.0 10.0

U.S. No. 4 48.0 95.0 93.0 3.0 3.0 10.0 10.0

Two-rowed Malting barley that does not meet the requirements for U.S. Nos. 1, 2, 3, or 4 

Malting is graded under the Barley standards.

Barley is divided into three subclasses: Six-rowed barley, Two-rowed barley, and Barley. 

Six-rowed Barley is any six-rowed barley that contains not more than 10.0 percent two-rowed 

varieties.

Two-rowed Barley is any two-rowed barley with white hulls that contains not more than 10.0 

percent six-rowed varieties.

 Two-Row Six-Row
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Barley is any barley that does not meet the requirements for the subclasses Six-rowed barley 

or Two-rowed barley.

All subclasses of Barley are divided into five numerical grades and U.S. Sample grade. 

The factors affecting the numerical grade include: test weight per bushel, sound barley, 

damaged kernels total, foreign material, broken kernels, and thin barley.

Barley Grade Requirements

BARLEY

Grade

Minimum Limits of - Maximum Limits of -

Test weight 

per bushel 

(pounds)

Sound 

barley1

(percent)

Damaged 

kernels1

(percent)

Heat 

Damaged

(percent)

Foreign 

material

(percent)

Broken 

kernels 

(percent)

Thin

barley*

(percent)

U.S. No. 1 47.0 97.0 2.0 0.2 1.0 4.0 10.0

U.S. No. 2 45.0 94.0 4.0 0.3 2.0 8.0 15.0

U.S. No. 3 43.0 90.0 6.0 0.5 3.0 12.0 25.0

U.S. No. 4 40.0 85.0 8.0 1.0 4.0 18.0 35.0

U.S. No. 5 36.0 75.0 10.0 3.0 5.0 28.0 75.0

Sample Grade

U.S. Sample grade is barley that does not meet the requirements for the grades U.S. 

Nos. 1, 2, 3, 4, or 5; or contains stones, glass, crotalaria seeds, castor beans, unknown 

foreign substances or commonly recognized harmful or toxic substances, cockleburs or 

similar seeds, rodent pellets, bird droppings or other animal filth or has a musty, sour, or 

commercially objectionable foreign odor; or is heating or otherwise of distinctly low quality.

Heating

Barley developing a high temperature from microbial activity is considered heating. 

Heating barley, in its final stages, will usually have a sour or musty odor. 

Care should be taken not to confuse barley that is heating with barley that is warm and moist 

because of storage in bins, railcars, or other containers during hot weather.

Determine heating on evidence obtained at the time of sampling or on the basis of the 

sample as a whole.

Grade heating barley as U.S. Sample Grade and record the word “Heating” in the “Remarks” 

section of the certificate.
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Distinctly Low Quality

Consider barley distinctly low quality when it is obviously of inferior quality and the existing 

grade factors or guidelines do not properly reflect the inferior condition. Use all available 

information to determine whether the barley is of distinctly low quality. This includes a general 

examination of the barley during sampling and an analysis of the obtained sample.

Barley containing two or more stones, pieces of glass, pieces of 

concrete, or other pieces of wreckage or debris which are visible to the 

sampler and too large to enter the sampling device is considered 

distinctly low quality.

Barley that is obviously affected by other unusual conditions which 

adversely affect the quality of the barley and cannot be properly 

graded by use of the grading factors specified or defined in the 

standards is considered distinctly low quality. Grade distinctly low 

quality barley as U.S. Sample Grade.

Record the words “Distinctly Low Quality” and the reason why in the “Remarks” section of 

the certificate.

Special Grades

Special grades draw attention to unusual conditions in the grain and are made part of the 

grade designation. They do not affect the numerical or sample grade designation.

Special grades in barley are: Blighted Barley, Ergoty Barley, Garlicky Barley, Infested Barley, 

and Smutty Barley.

Ergot

Smutty

Garlicky

Blighted

Infested
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Blighted barley is barley that contains more than 4.0 percent of fungus-damaged and/or 

mold-damaged kernels.

Ergoty barley is barley that contains more than 0.10 percent ergot. 

Garlicky barley is barley that contains three or more green garlic bulblets, or an equivalent 

quantity of dry or partly dry bulblets in 500 grams of barley. 

Infested barley is barley that is infested with live weevils or other live insects injurious to 

stored grain.

Smut is a plant disease characterized by the appearance of smut balls or smut spores. 

Smutty barley is barley that has kernels covered with smut spores to give a smutty 

appearance in mass, or which contains more than 0.20 percent smut balls.

Processing the Original Sample

The first step in grading a barley sample is to use a Boerner divider to reduce the original 

sample of approximately 2500 grams into: 

• a file sample of approximately 1250 grams; and 

• a work sample of 850-950 grams of grain.

Original

Sample

File Work
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Boerner Divider

The Boerner divider reduces the size of a grain sample while maintaining its 

representativeness. Each pass of the sample through the divider splits the sample into two 

equal portions. 

Boerner Divider

B

DUCTS CONNECTED

 BELOW BASE OF CONE

DUCTS WHICH

 SPROUT INTO

 INNER FUNNEL

SPACES WHICH

 OPEN INTO SECTION OUTER FUNNEL OF CONE

BASE OF CONE

PEAK OF CONE

A

INNER FUNNEL OUTER FUNNEL

RECEPTACLE

SPACES WHICH OPEN

 INTO OUTER FUNNEL

DUCTS WHICH SPROUT

 INTO INNER FUNNEL

CUT-OFF

HOPPER

CONE

The Boerner Divider, consists of a hopper, inverted cone, and a series of baffles directing 

the grain into two collection pans. As the valve or gate at the base of the hopper is opened, 

gravity carries the grain over the cone, which serves as a surface by which the kernels 

can separate into a single layer. Arranged in a circle at the base of the cone are a series of 

baffles forming alternate channels and spaces of equal width. They are arranged in a circle 

at their summit and are directed inward and downward, the channels leading to one spout 

and the spaces to an opposite spout. Each kernel has an equal chance of falling into a 

channel or a space, resulting in two nearly identical portions of the original sample.
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When Operating the Boerner Divider:

Check the divider for condition and 

cleanliness.

Close the hopper valve.

Place empty collection pans under the 

discharge spout.

Pour the sample into the hopper.

Open the valve quickly.

For larger samples, feed more grain into 

the hopper during the dividing process.

File Sample

A “file sample,” is a representative sample or representative portion of a sample that is 

retained for a specified period of time for reference or review purposes.

File samples should be of sufficient size to accommodate subsequent examinations or 

analysis. 

The file sample shall be an unworked portion (if available) of the representative sample used 

for the inspection. 

The worked portion may be retained as the final file only when insufficient sample is 

available for an unworked file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, or 

similar containers that allow moisture 

losses. Use metal cans, plastic containers, 

and plastic bags to preserve the sample 

integrity. 

Do not file samples with paper identification 

inserted in the grain. Paper absorbs moisture 

and lowers the moisture of the grain.
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Moisture

Determine moisture before the removal of dockage on a portion of approximately 650-750 

grams of grain.

 Dickey-john Perten

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. Basically, the instruments 

measure the change in capacitance of two parallel plates when grain is placed between 

them. As the moisture content within the grain increases or decreases so does its 

contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.

Record the percent of moisture on the certificate to the nearest tenth percent.
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Check for Sample Grade

Before the removal of dockage check the work portion for sample grade factors. Samples 

meeting or exceeding any one of these tolerances are Sample Grade:

Cocklebur

Castor Bean

Stones

Rodent

Excreta

Crotalaria

Glass

• 2 or more pieces of glass

• 3 or more crotalaria seeds

• 2 or more castor beans

• 4 or more particles of an unknown 

 foreign substance or a commonly 

 recognized harmful or toxic substance

• 8 or more cocklebur or similar 

 seeds singly or in combination

• 10 or more rodent pellets, bird droppings,

or equivalent quantity of other animal filth 

• or is heating or otherwise of distinctly low 

quality.

Check for Garlic

Determine garlicky before the removal of dockage on a work portion of 500 grams.

Garlicky barley is barley that contains three or more green garlic bulblets, or an equivalent 

quantity of dry or partly dry bulblets in 500 grams of barley. 

Green garlic bulblets are bulblets which have retained all of their husks intact. Dry or partly 

dry garlic bulblets are bulblets which have lost all or part of their husks. Consider bulblets 

with cracked husks as dry.

Three dry or partly dry garlic bulblets are equal to one green bulblet.
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Dockage

Determine dockage on a portion of 850-950 grams. 

 Air Riddle Thru #6 Sieve

Dockage is all matter other than barley that can be removed from the original sample using a 

Carter Dockage tester. Also, underdeveloped, shriveled, and small pieces of barley kernels 

removed in properly separating the material other than barley and that cannot be recovered 

by properly re-screening or re-cleaning.

When the sample contains 0.50 percent or more dockage, record the percentage of dockage 

on the certificate in half and whole percent with a fraction less than one-half percent 

disregarded.

Mechanical Cleaning

To mechanically clean the sample on the Carter Dockage tester:

• Set the air control on 4 and set the 

feed control to 6.

• Insert a No. 6 riddle in the riddle 

carriage, a No. 8 sieve in the top 

sieve carriage, and a No. 6 sieve 

in the middle sieve carriage. 

• No sieve is required in the bottom 

sieve carriage.

• Start the Carter Dockage Tester 

and pour 850-950 grams of barley 

into the feed hopper.

Carter Dockage Tester
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Rescreening

Dockage is the Aspirated material in the air collection pan, the material passing over the No. 

6 riddle, excluding barley, and the material that passed through the No. 6 sieve, in the bottom 

collection pan. 

Examine the material that passed over the No. 6 sieve to determine if it contains more than 

0.1 percent of wild buckwheat, mustard seed, or similar seed. If so, this material must be 

rescreened using a 5/64 inch equilateral triangular hole sieve.

To rescreen, place the material on the upper edge of the 5/64 inch sieve, hold the sieve at 

a 10-20 degree angle and work the material down over the sieve with a gentle side-to-side 

motion.

Return barley and other material remaining on top of the 5/64 inch sieve to the dockage-free 

sample. The material passing through the hand sieve is dockag

Check for Insects

Infestation is determined on the lot as a whole or the sample as a whole before the removal 

of dockage. However, to save time, many inspectors check for insects after dockage 

is removed. This is permissible as long as both the dockage and cleaned sample are 

thoroughly examined for insects.

The presence of any live weevil or other live insects injurious to stored grain found in the 

work sample indicates the probability of infestation and warns that the barley must be 

carefully examined to determine if it is infested. 

In such cases, examine the work sample and the file sample before reaching a conclusion as 

to whether or not the barley is infested. Do not examine the file sample if the work portion is 

insect free. Samples meeting or exceeding any one of these tolerances are infested: 

• 2 live weevils

• 1 live weevil + 5 other live insects

• 10 other live insects
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Live Weevils

Live weevils include rice weevils, 

granary weevils, maize weevils, 

cowpea weevils, and lesser grain 

borers.

Other Live Insects

Other live insects injurious to stored grain shall include grain beetles, grain moths, and 

larvae.

Check Odor

Determine odor on evidence obtained at the time of sampling or on the sample before or after 

the removal of dockage. Odors are classified as OK, Musty, Sour, or COFO (commercially 

objectionable foreign odors). 

Musty odors indicate the presence of fungal activity in the grain and are generally 

characterized as an earthy smell.

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are 

often characterized as an acrid, boot pit or pigpen smell.

Commercially objectionable foreign odors are odors foreign to grain that render it unfit for 

normal commercial usage. Fumigant or insecticide odors are considered commercially 

objectionable foreign odors if they linger and do not dissipate.

 Granary Weevil Lessor Grain Borer
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Check for Stones

After the removal of dockage, check for stones. 

Samples containing 8 or more stones or any number of stones which have an aggregate 

weight in excess of 0.2 percent of the sample weight are Sample Grade.

Test Weight per Bushel

The weight per Winchester bushel for barley is determined on the original sample after the 

removal of dockage on a portion of sufficient quantity to overflow the kettle. 

A Winchester bushel is 2150.42 cubic inches or 35.24 liters.

To determine test weight position the hopper over the center of the kettle, making sure the 

hopper valve is closed. Pour grain into the hopper. 

 Filled Hopper Open the Valve

Open the valve allowing the grain to overflow the kettle. Once the hopper is clear of grain 

move the hopper to the side. 

With a rounded edge striker, place it on the edge of the kettle and move the striker in three 

zigzag motions across the kettle leveling the grain. 

 Strike-off Procedure Weigh the Grain
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Move the kettle to a scale and record the test weight measurement.

Record test weight results on the work record as displayed on the electronic scale or in whole 

and half pounds. 

Record the test weight on the certificate in whole and half pounds. Disregard fractions of a 

half pound. 

If requested, convert the pounds per bushel result to kilograms per hectoliter by multiplying 

the lbs. / bu result by 1.287 and record in the “Remarks” section in whole and tenths

Processing the Work Sample

At this point, all tests required to be performed prior to the removal of dockage have been 

made and the percentage of dockage has been determined. 

Using the Boerner divider divide the work sample, into fractional portions for other 

determinations required after the removal of dockage. 
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Check for Smut

Determine the appearance of smutty barley and/or the weight of smut balls on a dockagefree work portion of 500 grams. Smut balls also function as foreign material.

Smut is a plant disease characterized by the 

appearance of smut balls or smut spores. 

Smutty barley is barley that has kernels covered 

with smut spores to give a smutty appearance in 

mass, or which contains more than 0.20 percent 

smut balls.

Check for Ergot

Determine ergoty on a dockage-free portion of 

250 grams. 

Ergot is a hard, reddish-brown or black grain-like 

mass of certain parasitic fungi that replaces the 

kernels of barley. Ergoty barley is barley that 

contains more than 0.10 percent ergot.

Determine Thin Barley

Thin barley is determined by sieving a dockage-free portion of 250 grams. 

In Malting barley thin is defined as: Six-rowed Malting barley that passes through a 5/64” x 

3/4” slotted-hole sieve and Two-rowed Malting barley that passes through a 5.5/64” x 3/4” 

slotted-hold sieve. 

In barley thin is defined as: Six-rowed barley, Two-rowed barley, or Barley that passes 

through a 5/64” x 3/4” slotted-hole sieve. 

Mount the applicable sieve and bottom pan on a mechanical sieve shaker set for 30 strokes. 

Return any material lodged in the perforations to the barley which remained on top of the 

sieve.

Record the percentage of thin barley on the work record and the certificate to the nearest 

tenth percent.
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Determine Plump Barley

Plump barley is also determined by sieving a dockage-free portion of 250 grams. Plump 

barley is defined as: Barley that remains on top of a 6/64” x 3/4” inch slotted-hole sieve after 

sieving.

Mount the applicable sieve and bottom pan on a mechanical sieve shaker set for 30 strokes. 

Return any material lodged in the perforations to the barley which remained on top of the 

sieve.

When requested, show the word “Plump” and the applicable percentage range in the 

“Remarks” section of the certificate. Plump barley is certified in five percent ranges. 

Percentage ranges are recorded as: 

• Below 50 percent • 50 to 55 percent 

• 56 to 60 percent • 61 to 65 percent, etc.

Sieving Procedure

Mechanical sieving is preferred over hand-sieving because the results are more uniform and 

accurate in counting the number of strokes. When sieving barley to determine plump or thin:

• Make sure the shaker is level.

• Select the proper sieve and place it over a bottom pan. 

• Mount the sieve and bottom pan in the sieve holder making sure that the slotted or 

oblong perforations are parallel with the sieving action.

 

• Set the stroke counter for 30 strokes.

 Mount Sieve Set Stroke Count

• Gently pour the dockage-free 250-gram portion in the center of the sieve.

• Turn the machine on.
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 Pour in Center Start Shaker

• After the required number of strokes has been completed, the machine will 

automatically stop.

• Carefully remove the sieve and bottom pan. Jarring the sieve will cause the material 

remaining on top to pass through the perforations, leading to inaccurate results.

• Combine the material lodged in the 

perforations with the material that remained 

on top of the sieve. To remove the lodged 

material from the perforations, rub the sieve 

bottom gently. 

Tapping will warp the sieve and lead to 

inaccurate results in future determinations.

Remove lodged Kernels

Determine Class & Subclass

Determine the class and subclass of barley by examining kernel and varietal characteristics 

on a dockage-free portion of 25 grams. 

Two-rowed barley is usually characterized 

by plump symmetrical kernels with tight 

creases straight down the center of the 

kernels. Two-rowed barley often has a 

slightly wrinkled skin that is generally thinner 

than the skin of Six-rowed barley. 

Two-Row Barley
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October 2016

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Six-rowed barley is usually characterized 

by long, irregularly shaped kernels. The 

germs and creases in most Six-rowed barley 

kernels are twisted with the crease flaring 

open at the end of the kernel. Some kernels, 

however, have germs and creases which are 

straight. 

Six-Row Barley

Damaged Kernels

Determine damaged kernels on a dockage free portion of 

25 grams.

Damaged Kernels are kernels, pieces of barley kernels, 

other grains, and wild oats that are badly grounddamaged, badly weather-damaged, diseased, frostdamaged, germ-damaged, heat-damaged, injured-byheat, insect-bored, mold-damaged, sprout-damaged, or 

otherwise materially damaged.

Record the percent of damaged kernels on the work 

record and the certificate to the nearest tenth percent.

Visual Reference Images

Because of the subjectivity involved 

in determining damage, and other 

subjective criteria, it is critical that 

visual references are available 

to ensure that interpretations are 

uniformly and consistently applied 

throughout the national system. 

Color images provide a basis for 

communicating the minimum “line” for 

various types of damage and other 

visually determined criteria.
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October 2016

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Blight-Damaged 

Blight damage is kernels and pieces of kernels 

affected with blight to the extent that the 

discoloration covers at least one-third of the 

surface area shown (singularly or in combination) 

with an intensity equal to or greater than shown. 

Blight is considered damage in all classes of 

Barley. 

Do not confuse blight damage with badly stained, 

weathered, or water-stained kernels. 

Six-rowed Malting Barley may not contain more 

than 4.0% blight/mold damage. More than 4.0% 

of blight and/or mold makes the special grade 

“blighted”.

Mold-Damaged

Mold-damaged is kernels and pieces of kernels in 

which the discoloration is spotted or blotched. 

Discoloration may appear on one or both sides 

but must be equal to or greater than the combined 

surface area depicted on both kernels. 

Mold is considered damage in all classes of 

Barley. 

Two-rowed Malting Barley may not contain more 

than 0.4% mold damage. More than 4.0% of blight 

and/or mold damaged kernels makes the special 

grade “blighted.”

Frost-Damaged Kernels

Frost damage is kernels, pieces of barley kernels, 

other grains, and wild oats that are badly 

shrunken and/or distinctly discolored black or 

brown by frost.

Kernels and pieces of barley (with or without the 

hull) that are distinctly discolored green, brown, 

or black to the minimum intensity shown are 

considered damage. Kernels are usually shrunken 

or indented. 
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October 2016

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The illustration shows from left to right:

Kernel 1: The minimum degree of discoloration 

for green.

Kernel 2: The minimum degree of discoloration 

for brown or black.

Malting barley may not contain more than 0.4% 

frost damage. Frost-damaged kernels are 

scored as damaged kernels and against sound 

barley limits.

Germ-Damaged (Sick / Mold)

Germ-damaged kernels are kernels that have 

discolored or moldy germs as a result of microbial 

activity. Scrape the germs carefully to avoid 

scraping too deeply and destroying the evidence 

of damage. The illustration shows from left to 

right:

Kernel 1: Kernels and pieces of barley that have discolored germs as dark as or darker 

than shown shall be damaged. Discolored germs that do not meet the minimum coverage 

requirement may be considered damage provided the degree of discoloration is greater than 

shown and the overall “prorated” appearance meets the minimum coverage and intensity 

level depicted.

Kernel 2: Kernels containing any amount of mold shall be damage. Mold occurs in many 

colors other than shown.

Heat-Damaged

Determine heat-damaged kernels on a 50 

gram pearled portion. Heat-damaged kernels 

are Kernels and pieces of barley which, after 

the standardized full pearl, are materially 

discolored (red, black, or brown) to the 

minimum extent shown when viewed from the 

top. The illustration shows from left to right:

Kernel 1: Minimum color intensity for Blue barley.

Kernel 2: Minimum color intensity for barley other than Blue barley.

Malting barley may not contain more than 0.1% heat-damaged kernels.
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October 2016

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Weevil or Insect-Bored

Weevil or insect-bored barley is kernels 

and pieces of barley kernels which have 

been bored or tunneled by insects. 

The illustration shows from left to right:

Kernel 1: which has been tunneled.

Kernels 2 & 3: which have been bored.

Sprout-Damaged

Sprout-damaged kernels are kernels and 

pieces of barley that have sprouted or 

have swelling over the germ and, after 

examination, show sprout. The illustration 

shows from left to right:

Kernel 1: This kernel is showing visible 

sprout at the bottom of the germ area.

Kernel 2: Kernels which, after careful 

removal of the seed coat, show any 

evidence of movement in the germ area. 

The “sprout” may move towards the top or 

bottom of the germ or lift upward leaving 

space between the sprout and germ cavity.

Swelling over the germ area may or may 

not be an indication of sprout.

Check for Blighted Barley

Determine blighted barley on the dockage-free portion of 25 grams used for damage.

Designate barley containing more than 4.0 percent of fungus-damaged and/or molddamaged kernels as “Blighted.”
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Malting Factors

In addition to the grading factors listed in the grade and grade requirements tables, other 

limits have been established for malting barley. Malting Factors along with the grade factors, 

are determined before designating the class or subclass of barley. 

MALTING FACTORS

Subclass

Maximum limits of:

Frost 

Damage

Injuredby-FrostHeat 

Damage

Injuredby-HeatMold 

Damage

Injuredby-MoldKernel 

Texture

Six-rowed 

Malting and 

Six-rowed Blue 

Malting

0.4% 1.9% 0.1% 0.2% --- --- 90%

Two-rowed 

Malting 0.4% 1.9% 0.1% 0.2% 0.4% 1.9% ---

Basis of 

Determination 25 g 25 g 50 g 50 g 25 g 25 g 50 g

The determinations for Frost Damage, Heat damage, Injured by heat, and Mold damage, can 

be based on the separation made for damaged kernels. 

The determinations for Injured by mold and Injured-by-Frost can also be made on the 25 

gram portion used for damaged kernels, although these factors are not included in the 

damaged kernels determination. 

The determination for kernel texture is made on a 50 gram pearled portion. 

Upon request, malting factors may also be determined on barley that is not considered as a 

malting type.

Injured-by-Heat

Injured-by-heat kernels are kernels and pieces of 

barley which, after the standardized one-third pearl, 

are slightly discolored to the minimum extent shown 

when viewed from the top. The illustration shows 

from left to right:

Kernel 1: Minimum color intensity for Blue barley 

Kernel 2: Minimum color intensity for barley 

Malting barley may not contain more than 0.2% 

injured-by-heat. Do not confuse with heat-damaged 

barley.
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October 2016

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Injured-by-Frost

Injured-by-frost is kernels and pieces of 

kernels that are distinctly indented, immature 

or shrunken, or discolored as a result of frost. 

Injured-By-Frost is a malting factor only and 

does not function as damage or against sound 

barley. Malting barley may not contain more 

than 1.9% Injured-By-Frost damage.

Injured-by-Mold

Injured-by-mold kernels are kernels, pieces of 

barley kernels containing slight evidence of 

mold.

Injured-by-mold kernels are characterized 

by mold spores and have a weathered 

appearance.

Kernel Texture

Kernel texture is the color of the aleurone layer. Determine kernel texture by pearling a 50 

gram dockage-free portion. 

90% or more White Aleurone

Six-rowed Malting Barley

90% or more Blue Aleurone

Six-rowed Malting Barley

Six-rowed Malting barley consists of 90.0 percent or more of kernels with white aleurone 

layers.

Six-rowed Blue Malting barley consists of 90.0 percent or more of kernels with blue aleurone 

layers.
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October 2016

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Barley Pearler Procedure

The barley pearler is used in the determination or 

heat-damage, injured-by-heat, kernel texture, and 

sprout.

Before pearling a sample, run the pearler and open 

the slide to ensure that the pearling chamber is 

empty.

Remove and empty the drawers that catch the 

barley hulls and pearled portion, replace the 

drawers and securely close the slide.

Pour 50 grams of dockage-free barley into the 

pearler and replace the lid.

Set the timer for the factor being determined.

• Use a full standardized Pearl for heat 

damage

• Use a 1/3 pearl for Injured-by-Heat 

and Kernel Texture

• Use a 1/5 pearl for injured by sprout

After pearling, pull out the slide and allow the 

pearled portion to drop into the drawer. With the 

slide open, briefly restart the machine and clear the 

pearling chamber. Proceed with the determination 

as described for the appropriate factor.
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October 2016

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Standardizing the Pearler

To standardize a barley pearler it must be referenced to a pearler that has been standardized 

to the GIPSA Master Pearler using the following procedure:

First, obtain a sample that has been tested on a standardized pearler. Two-rowed barley 

is preferred for standardization purposes because it is more uniform than six-rowed barley. 

Use a Boerner divider to cut out four approximately 50 gram portions from the sample. Hand 

adjust each portion to 50.0 grams.

Pearl the first portion for 60 seconds. Compare the weight of the pearled portion to the 

weight obtained from the Standard pearler.

The results should be within plus or minus 1.0 gram of the results from the Standard pearler.

If not, adjust the pearling time in 15 second increments and pearl additional portions, until 

the weight of the pearled portion is within plus or minus 1.0 gram of the Standard pearler. 

Increase the time if the weight was high and decrease the time, if the weight was low. Some 

pearlers may require adjustment in increments smaller than 15 seconds.

The pearling time required to obtain results within plus or minus 1.0 gram of the Standard 

pearler, is established as the “Full Pearl” time for the pearler.

Record the pearling time on a piece of paper and tape it to the pearler in a conspicuous place 

for easy reference.

The carborundum pearling wheel will wear through use, increasing the time required to pearl 

a sample. This will require that the pearler be re-standardized periodically. The pearlers 

used in the official system are checked annually.

Foreign Material

Determine foreign material on a dockagefree portion of 25 grams.

Foreign Material is all matter other than 

barley, other grains, and wild oats that 

remains in the sample after the removal of 

dockage.

Record the percent of foreign material on 

the work record and the certificate to the 

nearest tenth percent.
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October 2016

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Wild Oats

Determine wild oats on a dockage-free portion of 25 

grams. 

Wild oats are usually identified by their slender kernels 

and twisted awns (so called “sucker mouths”) and basal 

hairs or bristles on the germ end of the kernel. 

Other grains is a grading factor in the subclasses Six-rowed Malting barley and Six-rowed 

Blue Malting barley and are not considered as sound in all classes and subclasses of barley.

Sound Barley

Sound barley is kernels and pieces of barley kernels that are not damaged and includes:

• Skinned and broken kernels of barley which are not damaged,

• Broken kernels which are not damaged,

• Green immature kernels of barley not otherwise damaged, and

• Kernels which are considered injured-by-frost and/or injured-by-mold.

Sound barley does not include damaged kernels of barley and material other than barley.

The percentage of sound barley is the sum of the percentages of damaged kernels, foreign 

material, other grains, and wild oats subtracted from 100 percent. Record the percentage of 

sound barley on the work record and the certificate to the nearest tenth percent.

A grade determining factor only in the subclass Two-rowed Malting barley, wild oats is 

deducted from the percentage of sound barley in all other classes and subclasses of barley.

Other Grains

Determine other grains on a dockage-free 

portion of 25 grams. 

Other grains are Black barley, corn, cultivated 

buckwheat, einkorn, emmer, flaxseed, guar, 

hull-less barley, nongrain sorghum, oats, 

Polish wheat, popcorn, poulard wheat, rice, 

rye, safflower, sorghum, soybeans, spelt, 

sunflower seed, sweet corn, triticale, and 

wheat. Canola, Oat groats, and hull-less oats 

are also considered as other grains. 
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October 2016

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Skinned and Broken Kernels

Determine skinned and broken kernels on a dockage-free portion of 25 grams. Skinned and 

broken kernels are barley kernels that have one-third or more of the hull removed, or that the 

hull is loose or missing over the germ, or broken kernels, or whole kernels that have a part or 

all of the germ missing. The illustration shows barley in which part of the germ is missing or 

the hull is:

 4 5 6

 1 2 3 Kernel 1: Loose over the germ area on both 

 sides and the front.

Kernel 2: Has one-third or more missing from

 the kernel. 

Kernel 3: Is missing or split over the germ 

 area. The germ area must be 

 visible when viewing from the top 

 only. 

Kernel 4: More than one-fourth of the kernel

 is broken off. 

Kernels 5 & 6: Is skinned on both sides of the kernel.

When malting barley does not meet the requirements for malting because it exceeds the limit 

for skinned and broken kernels, record the percentage of skinned and broken kernels on the 

work record and in the “Remarks” section of the certificate to the nearest tenth percent.

Broken Kernels

Determine broken kernels on a dockage-free portion 

of 25 grams. 

Broken kernels are barley kernels with more than 

1/4 of the kernel removed and are a gradedetermining factor in the class barley.

Other Official Criteria

Other tests that can be performed on barley include testing for the mycotoxin Deoxynivalenol, 

pesticide residue, and injured-by-sprout.
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October 2016

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Injured-by-Sprout

Kernels and broken kernels of barley which, after pearling, contain a visible germ area 

showing evidence of sprout, sprout socket, or 2/3 or more of the germ missing are 

considered “Injured by Sprout”. Also consider kernels as “Injured by Sprout” if the germ area 

has been broken off and the remaining kernel is at least 2/3 of a whole kernel. Injured by 

Sprout does not function as damage.

sprout

present

2/3 or more

germ missing

germ

missing

sprouted socket

Upon request determine injured-by-sprout on 55 grams plus or minus one gram divided from 

the dockage free work portion. By using a portion pearled by a standardized Barley pearler 

injured by spout kernels of barley can be determined more effectively. 

• Using a stopwatch, pearl the portion for 1/5 of the standardized full pearl time, plus or 

minus one second. 

• Using an aspirator or comparable devise, remove the excess hulls remaining in the 

pearled portion.

• Remove all the injured-by-sprout kernels from the portion.

Determine Grade Designation

After completing the analysis, compare the results with the limits for each grade factor.

The factor with the lowest grade designation determines the grade assigned to the sample.

The Official U.S. Standards for Grain provide an optional grade designation, commonly 

referred to as “or better.” 

Upon request of the applicant, barley may be certified as U.S. No. 2 or better, U.S. No. 3 or 

better, etc. 

An “or better” grade designation cannot be applied to U.S. No. 1 grade designation.
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October 2016

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Documenting the Grade

Use the following guidelines when documenting the grade.

First write the letters “U.S.” followed by the abbreviation “No.” and the number of the grade or 

the words “Sample grade”;

Then the words “or better” when applicable followed by the name of the subclass;

Next is the applicable special grades in alphabetical order followed by the word “dockage” 

and the percentage thereof.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 1

Chapter 2: Canola

Grain Grading Primer

Chapter 2

Canola
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 2

Contents

Chapter 2: Canola 1

Canola Definition ....................................................................................................................4

Canola Grades and Grade Requirements ...........................................................................5

Grade Requirements ..............................................................................................................5

Sample Grade .........................................................................................................................5

Heating ....................................................................................................................................6

Distinctly Low Quality ............................................................................................................6

Special Grades........................................................................................................................6

Processing the Original Sample ...........................................................................................7

Boerner Divider.......................................................................................................................7

File Sample..............................................................................................................................8

Use Moisture Proof Containers .............................................................................................8

Moisture ...................................................................................................................................9

Check for Sample Grade Factors .......................................................................................10

Check Odor ...........................................................................................................................10

Fumigant or Insecticide Odor ..............................................................................................11

Check for Garlic ....................................................................................................................11
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October 2016

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Check For Insects................................................................................................................ 11

Live Weevils .........................................................................................................................12

Other Live Insects .............................................................................................................. 12

Reduce Work Portion to 250g ............................................................................................ 13

Machine Separated Dockage .............................................................................................. 13

Mechanical Cleaning ........................................................................................................... 14

Reclaim.................................................................................................................................14

Conspicuous Admixture ..................................................................................................... 14

Computing Total Dockage .................................................................................................. 15

Damaged Kernels .............................................................................................................. 16

Visual Reference Images .................................................................................................... 16

Determine Damage .............................................................................................................. 18

Inconspicuous Admixture .................................................................................................. 19

Erucic Acid ...........................................................................................................................20

Oil..........................................................................................................................................20

Test Weight ..........................................................................................................................21

Determine Grade Designation ............................................................................................ 22

Documenting the Grade ...................................................................................................... 22
Grain Grading Primer Chapter 2: Canola

October 2016

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Canola Definition

Canola is defined as seeds of the genus Brassica from which the oil shall contain less than 

2 percent erucic acid in its fatty acid profile and the solid component shall contain less than 

30.0 micromoles of glucosinolate per gram of air-dried, oil free solid. 

Before the removal of dockage, the seed shall contain no more than 10.0 percent of other 

grains for which standards have been established under the United States Grain Standards 

Act.
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October 2016

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Canola Grades and Grade Requirements 

CANOLA

Grade

Maximum Limits of -

 Damaged kernels Conspicuous Admixture

Inconspicuous

Admixture

(percent) 

Heat

damaged

(percent)

Distinctly

green 

(percent)

Total 

(percent)

Ergot

(percent)

Sclerotinia

(percent)

Stones

(percent)

Total

(percent) 

U.S. No. 1 0.1 2.0 3.0 0.05 0.05 0.05 1.0 5.0

U.S. No. 2 0.5 6.0 10.0 0.05 0.10 0.05 1.5 5.0

U.S. No. 3 2.0 20.0 20.0 0.05 0.15 0.05 2.0 5.0

U.S. Sample Grade: 

U.S. Sample Grade shall be canola that: 

(a) Does not meet the requirements for grades U.S. No. 1, 2, 3; or 

(b) Contains 1 or more pieces of glass, 2 or more particles of an unknown foreign 

substance(s) or a commonly recognized harmful or toxic substance(s), or 4 or more 

pieces of animal filth; or 

(c) Has a musty, sour, or commercially objectionable foreign odor; or 

(d) Is heating or otherwise of distinctly low quality.

Grade Requirements

There are no classes or subclasses in canola. Canola is divided into three numerical grades 

and U.S. Sample grade. The factors affecting the numerical grade include: Heat Damage, 

Distinctly Green, Total Damage, Ergot, Sclerotinia, Stones, Conspicuous Admixture, and 

Inconspicuous Admixture.

Sample Grade

U.S. Sample grade is canola that does not meet the requirements for the grades U.S. Nos. 

1, 2, or 3; or 

• contains glass, 

• unknown foreign substances or 

• a commonly recognized harmful or toxic substance, 

• animal filth; 

• has a musty, sour, or commercially objectionable foreign odor; 

• is heating or 

• otherwise of distinctly low quality.
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October 2016

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Heating

Canola developing a high temperature from microbial activity (fermenting), insect infestation, 

or sprouting is considered heating. As heating progresses canola will develop a sour or 

musty odor. Care should be taken not to confuse canola that is heating with canola that is 

warm because of storage in bins, railcars, or other containers during hot weather.

Determine heating on evidence obtained at the time of sampling or on the basis of the 

sample as a whole.

Grade heating canola as U.S. Sample Grade and record the word “Heating” in the 

“Remarks” section of the certificate.

Distinctly Low Quality

Consider canola distinctly low quality when it is obviously of inferior quality and the existing 

grade factors or guidelines do not accurately reflect the inferior condition. Use all available 

information to determine whether the canola is of distinctly low quality. This includes 

a general examination of the canola during sampling and an analysis of the obtained 

sample(s).

Canola containing two or more stones, pieces of glass, pieces of concrete, or other pieces of 

wreckage or debris which are visible to the sampler but are too large to enter the sampling 

device is considered distinctly low quality.

Canola that is obviously affected by other unusual conditions which adversely affect the 

quality of the canola and cannot be properly graded by use of the grading factors specified 

or defined in the standards is considered distinctly low quality.

Grade distinctly low quality canola as U.S. Sample Grade. Record the words “Distinctly Low 

Quality” and the reason(s) why in the “Remarks” section of the certificate.

Special Grades

Special grades identify unusual conditions in grain and are part of the grade designation. 

They do not affect the numerical or sample grade designation. The canola standards 

include two special grades. 

The special grade garlicky is applied to canola that 

contains more than two green garlic bulblets or an 

equivalent quantity of dry or partly dry bulblets.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 7

The special grade infested is applied to canola that is 

infested with live weevils or other live insects injurious to 

stored grain.

Processing the Original Sample

The first step in grading a canola sample is to use a 

Boerner divider to reduce the original sample into an:

• 850 gram file sample, and a 

• 500 gram work portion.

Boerner Divider

The Boerner divider reduces the size 

of a grain sample while maintaining its 

representativeness. Each pass of the 

sample through the divider splits the 

sample into two equal portions. The 

Boerner Divider, consists of a hopper, 

inverted cone, and a series of baffles 

directing the grain into two collection 

pans. As the valve or gate at the base 

of the hopper is opened, gravity carries 

the grain over the cone, which serves 

as a surface by which the kernels can 

separate into a single layer. Arranged 

in a circle at the base of the cone are 

a series of baffles forming alternate 

channels and spaces of equal width. 

They are arranged in a circle at their 

summit and are directed inward and 

downward, the channels leading to one 

spout and the spaces to an opposite 

spout. Each kernel has an equal 

chance of falling into a channel or a 

space, resulting in two nearly identical 

portions of the original sample.
Grain Grading Primer Chapter 2: Canola

October 2016

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When Operating the Boerner Divider:

• Check the divider for condition and cleanliness.

• Close the hopper valve.

• Place empty collection pans under the discharge spout.

• Pour the sample into the hopper.

• Open the valve quickly.

For larger samples, feed more grain into the hopper during the dividing process.

File Sample

A “file sample,” is a representative sample 

or representative portion of a sample that 

is retained for a specified period of time for 

reference or review purposes. File samples 

should be of sufficient size to accommodate 

subsequent examinations or analysis. 

The file sample shall be an unworked 

portion (if available) of the representative 

sample used for the inspection. The worked 

portion may be retained as the final file only 

when insufficient sample is available for an 

unworked file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, or 

similar containers that allow moisture losses. 

Use metal cans, plastic containers, and plastic 

bags to preserve the sample integrity. 

Do not file samples with paper identification 

inserted in the grain. Paper absorbs moisture 

and lowers the moisture of the grain.
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October 2016

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Moisture

Moisture is the water content of sorghum as determined by an approved device before the 

removal of dockage. Record the percent of moisture on the certificate to the nearest tenth 

percent. 

Determine moisture before the removal of dockage on a portion of approximately 650 – 750 

grams of grain.

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. 

Basically, the instruments measure the change in capacitance of two parallel plates when 

grain is placed between them. As the moisture content within the grain increases or 

decreases so does its contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.

Record the percent of moisture to the nearest tenth percent.

 DICKEY-john GAC2500 Perten AM5200-A
Grain Grading Primer Chapter 2: Canola

October 2016

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Check for Sample Grade Factors

Check the 500 gram work portion for U.S. Sample grade criteria, before the removal of 

dockage.

Canola is Sample Grade if the work portion contains:

• 2 or more particles of an unknown foreign substance(s) or a commonly recognized 

harmful or toxic substance(s), 

• 1 or more pieces of glass, 

• or 4 or more pieces of animal filth.

Check Odor

Determine odor on evidence obtained at the time of sampling, on the sample either before or 

after the removal of dockage, or on the crushed strips used to determine heat damage and 

distinctly green damage. When the crushed strips are used, determine the odor immediately 

after crushing. 

Odors are classified as OK, Musty, Sour, or COFO (commercially objectionable foreign 

odors). 

Musty odors indicate the presence of fungal activity in the grain and are generally 

characterized as an earthy smell.

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are 

often characterized as an acrid, boot pit or pigpen smell.

When heat-damaged kernels are present, canola gives off an odor very similar to smoke. 

Canola containing a “smoke” odor is considered as having a “sour” odor unless evidence 

of a fire-burnt material is present in the lot or the original sample. If evidence of a fire-burnt 

material is present in the lot or the sample, the smoke odor is considered a commercially 

objectionable foreign odor.

Commercially objectionable foreign odors are odors foreign to grain that render it unfit for 

normal commercial usage.
Grain Grading Primer Chapter 2: Canola

October 2016

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Fumigant or Insecticide Odor

Fumigant or insecticide odors are considered 

commercially objectionable foreign odors if they linger 

and do not dissipate. 

 When a sample of canola contains a fumigant or 

insecticide odor that prevents a determination as to 

whether any other odors exists, allow the work portion 

to aerate in an open container for 4 hours, or less, if the 

odor dissipates in less time. Consider the sample as 

having a commercially objectionable foreign odor if the 

fumigant or insecticide odor persists after 4 hours.

Grade canola containing a “distinct” musty, sour, or 

commercially objectionable foreign odor as U.S. Sample 

grade.

Check for Garlic

Check for the special grade garlicky, before the removal 

of dockage on a work portion of 500 grams. 

If the 500 gram portion contains more than two green 

garlic bulblets or an equivalent quantity of dry or partly 

dry bulblets the special grade garlicky applies.

Green garlic bulblets are bulblets which have retained 

all of their husks intact.

Dry or partly dry garlic bulblets are bulblets which have 

lost all or part of their husks. Consider bulblets with 

cracked husks as dry.

Three dry or partly dry garlic bulblets are equal to one 

green bulblet.

Green Garlic Bulblets

Dry Garlic Bulblets

Check For Insects

Check for the special grade Infested on the lot as a whole or before the removal of dockage 

on a work portion of 500 grams. Infested canola is canola that is infested with live weevils or 

other live insects injurious to stored grain.

The presence of any live weevil or other live insects injurious to stored grain found in the 

work sample indicates the probability of infestation and warns that the canola must be 

carefully examined to determine if it is infested. In such cases, examine the work sample 

and the file sample before reaching a conclusion as to whether or not the canola is infested. 
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 12

Do not examine the file sample if the work sample is insect free. 

Samples meeting or exceeding one of these tolerances are infested:

Live Weevils

Live weevils include rice weevils, granary weevils, maize weevils, cowpea weevils, and 

lesser grain borers. 

Rice

Weevil

Granary

Weevil

Maize

Weevil

Cowpea

Weevil

Lessor Grain

Borer

Other Live Insects

Other live insects injurious to stored grain shall include grain beetles, grain moths, and 

larvae.

Angoumois

Grain Moth

Indian Meal

Moth

Red Flour

Beetle

Flat 

Grain

Beetle
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 13

Reduce Work Portion to 250g.

At this point, determinations have been made for kind of grain, infestation, heating, odor, 

garlic bulblets, sample grade criteria, and moisture. Now use a Boerner divider to reduce the 

work portion to a 250 gram subsample for machine cleaning.

Machine Separated Dockage

Machine separated dockage is all material removed by aspiration, coarse material, except 

threshed and sprouted kernels of canola, that passed over the riddle, and material that 

passed through the Number 4 sieve, except for small whole and broken pieces of canola 

which are reclaimed.

250 gram 

sample Air #5

Feed #3

No. 4 

Top Sieve

Bottom Collection Pan

Reclaim small and 

broken canola using

hand sieves

DKG #4

Total DKG = DKG 1+2+3+4

Air Collection Pan

No. 000 DKG #1

Riddle

DKG #2

Remove threshed

& sprouted kernels

Mechanically

Cleaned 

Canola 

10 gram Subportion 

Hand separate canola from 

conspicuous admixture 

DKG #3
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 14

Mechanical Cleaning

First the sample is machine cleaned using the Carter Dockage Tester. To operate the Carter 

Dockage Tester, insert the 000 riddle in the riddle carriage, the number 4 sieve in the top 

sieve carriage, set the air to 5, and set the feed control to 3. 

Then, run the 250 gram portion through the dockage tester. Return kernels of canola caught 

in the riddle to the cleaned portion. Finally, Remove threshed and separated canola from 

material over the riddle and add to cleaned canola.

Reclaim

Next sieves are used to maximize the clean-out of weed seeds and similar foreign material 

with a minimum loss of canola. Visually examine the material that passed over the No. 4 

sieve. If the sample contains wheat, buckwheat, weed seeds, or similar foreign material, 

use a round-hole sieve to separate the material from the canola. 

• Sieve the material for 30 strokes. 

• Return the material passing through the sieve to the clean sample. 

• Use a .035 x 15/32 inch slotted sieve to reclaim small whole and broken pieces of canola 

that passed through the No. 4 sieve. 

• Sieve the material for 30 strokes. 

• Return the material remaining on the slotted-hole sieve and in the perforations to the 

clean sample and the material passing through the slotted-hole sieve to the dockage.

• Combine the two mechanically cleaned portions. 

Upon request, a .028 x 15/32 inch or .0395 x 15/32 inch slotted hole sieve may be used. When 

a requested sieve is used, record the sieve size in the remarks section of the certificate.

Conspicuous Admixture

After the canola has been machine cleaned, cut down the cleaned 

sample to a portion of not less than 10 grams. Handpick the 10-

gram portion for conspicuous admixture. 

Conspicuous Admixture is all matter other than canola, which is 

conspicuous and readily distinguishable from canola and which 

remains in the sample after the removal of machine separated 

dockage. Conspicuous admixture includes but is not limited to 

ergot, sclerotinia, and stones. Stones are concreted earthy or 

mineral matter and other substances of similar hardness that do 

not disintegrate in water. 
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 15

Ergot is a hard, reddish brown or black sclerotia of the Claviceps purpurea fungi that 

replaces the kernels of rye (its most common host), as well as triticale, wheat and barley. 

Sclerotinia are the dark colored sclerotia of the Sclerotinia fungi. 

 Stones Ergot Sclerotinia

Record the percentage of stones, ergot, and sclerotinia to the nearest hundredth percent.

Computing Total Dockage

In computing the total dockage, all mechanically separated dockage is computed on the 

basis of the sample as a whole. 

The percentage of conspicuous admixture or handpicked dockage, which is determined 

on the basis of the weight in grams of the portion used for the hand separation, must 

be multiplied by the fractional proportion of canola remaining after the removal of the 

mechanically separated dockage.

For Example: 

• if the original sample weight is 250 g, 

• the weight of mechanically separated dockage is 24.70 g, 

• the weight of the handpicked portion is 10.24 g, and 

• the weight of handpicked dockage or conspicuous admixture is 0.20 g.

Then the weight of the Dockage divided by the original sample weight multiplied by one 

hundred equals the percent of mechanically separated dockage or 9.88%.

One hundred percent minus the 9.88% mechanically separated dockage then divided by one 

hundred equals the change of base factor or 0.90.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 16

The weight of handpicked separation divided by the weight of the handpicked portion times 

one hundred equals the percent of conspicuous admixture or 1.95%.

The percent of conspicuous admixture times the change of base factor equals the adjusted 

conspicuous admixture or 1.75%. 

The adjusted conspicuous admixture plus the percent of mechanically separated dockage 

equals the total dockage or 11.63 percent which rounded to the nearest tenth is 11.6

Damaged Kernels

At this point, determinations have been made for dockage, conspicuous admixture, 

sclerotinia, stones, and ergot. Now reweigh the portion which was used for picking 

conspicuous admixture and use it to determine damage and inconspicuous admixture. 

Damage is canola and pieces of canola that are heat-damaged, sprout-damaged, molddamaged, distinctly green-damaged, frost-damaged, rimed-damaged, or otherwise materially 

damaged.

Damage must be distinct. In general, a kernel of canola is considered damaged when the 

damage is distinctly apparent and of such character as to be recognized as damaged for 

commercial purposes. 

Insect bored kernels are not considered damaged.

Visual Reference Images

Because of the subjectivity involved in determining damage, and other subjective criteria, 

it is critical that visual references are available to ensure that interpretations are uniformly 

and consistently applied throughout the national system. Color images provide a basis 

for communicating the minimum “line” for various types of damage and other visually 

determined criteria.

Sprout Damage

Sprout damaged kernels are canola and pieces of canola that are sprouted. The sprout must 

be distinct and equal to or greater than shown to be considered damage. Do not confuse 

spout damage with swollen Endosperm.

Canola and pieces of canola with swollen endosperm shall not be considered damage.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 17

Other Damage (Rimed & Frost)

 A B C

Distinctly green kernels are canola and pieces of canola which, after being crushed, are a 

distinct green. 

Any amount of coverage equal to or greater than the intensity shown is considered damage.

Disregard the crushed seed coat in making this determination.

Heat Damaged Kernels

Other damage includes canola and pieces of canola which are completely covered with a 

whitish, frosted coloration or “rime” and canola and pieces of canola which are distinctly 

shriveled or shrunken by frost to the degree illustrated.

A. Canola and pieces of canola which are completely covered with a whitish, frosted 

coloration (rime) shall be considered damage.

B. Canola and pieces of canola which are distinctly shriveled or shrunken (frost damaged)

 to the degree illustrated shall be considered damage.

C. Canola and pieces of canola containing the amount of surface mold depicted shall be 

considered damage.

Distinctly Green Kernels

Heat damaged kernels are canola and pieces of canola which, after being crushed, are 

materially discolored and damaged by heat. Any amount of coverage equal to or greater 

than the intensity shown is considered damage.

Disregard the crushed seed coat in making this determination.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 18

Determine Damage

To determine damage, first, handpick the 10 gram portion for distinctly shrunken or shriveled 

kernels as in frost- damaged kernels, kernels discolored by mold, rimed kernels, sprouted 

kernels, excessively weathered kernels, and any other kernels of canola that are distinctly 

damaged. These kernels are “other damaged” kernels. 

Then cut down the balance of the 10 gram portion to 5 grams and sprinkle the 5 gram 

portion across the damage seed counter to fill a 500 hole board. After filling the board and 

applying tape but before crushing, observe the strip for inconspicuous admixture. If a 100-

hole board is used repeat the process five times.

With a roller, crush the canola, examine the rows, and count the number of heat damaged 

kernels, distinctly green kernels, and seeds that are obviously not canola.

Finally, after the strip, or all 5 strips when using the 100 hole board, has been crushed and 

kernels counted, calculate the percentage of each type of damage.

Determine all percentages of damage, except for distinctly green and heat damaged kernels, 

upon the basis of weight. Determine the percentage of distinctly green and heat damaged 

kernels on the basis of count.

Add the percentage of distinctly green, heat damaged, and other damaged kernels of canola 

to compute damaged kernels total.

Record the percentages of heat damaged kernels, distinctly green kernels, and damaged 

kernels (total) on the certificate to the nearest tenth percent.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 19

Inconspicuous Admixture

Inconspicuous Admixiture includes any seed which is difficult to distinguish from canola. 

This includes, but is not limited to, common wild mustard, domestic brown mustard, yellow 

mustard, and seed other than the mustard group.

 Yellow & Wild Mustard Mix Brown Mustard Oriental Mustard

Make the determination for inconspicuous admixture on the 5-gram portion used in the 

determination for heat-damaged and distinctly green kernels.

Prior to crushing, mark any seeds suspected of not being canola and observe with a 

dissecting scope or magnifying glass. Use the reference samples and photographs as an aid 

in identification.

It is extremely important for inspectors to rely on a dissecting scope or a magnifying glass 

and the crushed strips for identification of inconspicuous admixture.

Any seeds suspected of not being canola should be marked to be confirmed after crushing. 

After crushing, canola tends to be a golden yellow while crushed wild mustard is pale yellow 

to white and cow cockle is white.

 Canola Yellow Mustard Cow Cockle Brown Mustard Wild Mustard

Calculate the percentage of inconspicuous admixture on the basis of count. Record the 

percentage of inconspicuous admixture to the nearest tenth percent.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 20

Erucic Acid

The long-chain fatty acid, erucic acid, is a component 

of canola and its oil. A high level of erucic acid is 

desired for the production of certain chemicals, 

industrial lubricants, fully hydrogenated rapeseed oil, 

and superglycerinated fully hydrogenated rapeseed oil. 

A low level is desired for the production of salad and 

vegetable oils, margarine, and shortening. 

An erucic acid test suitable for use in the field does not 

exist. However, an analysis for erucic acid content is 

available at the National Grain Center as a separate 

test. The erucic acid results are certificated to the 

nearest tenth percent independent of the grade 

certificate. 

If the erucic acid result is equal to or greater than 2.0 

percent, the applicant has the option of surrendering 

the outstanding grade certificate for corrections. Official 

personnel shall issue a “corrected certificate” labeling 

the seed as “not standardized grain” rather than canola. 

If a review inspection is performed for grade and official personnel know, based on previous 

testing, that the erucic acid content is equal to or greater than 2.0 percent, grade the review 

inspection “not standardized grain” and cross reference the certificate that reported the high 

erucic acid level.

Oil

Lipids are oils and fats that are liquid at room temperature. If an analysis for oil content is 

requested, submit a portion of 100 grams free of machine separated dockage to the National 

Grain Center. 

Certify the percentage of oil to the nearest tenth percent.
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 21

Test Weight

The weight per Winchester bushel is determined using an approved device according to 

procedures prescribed in FGIS instructions. A Winchester bushel is 2150.42 cubic inches or 

35.24 liters. Determine test weight on a dockage-free portion of sufficient quantity to overflow 

the kettle.

Position the hopper over the center of the 

kettle, making sure the hopper valve is 

closed. Pour grain into the hopper. 

Open the valve allowing the grain to 

overflow the kettle. Once the hopper is 

clear of grain move the hopper to the side. 

With a rounded edge striker, place it on 

the edge of the kettle and move the striker 

in three zigzag motions across the kettle 

leveling the grain. 

Move the kettle to a scale and record the 

test weight measurement.

Record test weight results in the “Remarks” 

section to the nearest tenth pound. If 

requested, convert the pounds per bushel 

result to kilograms per hectoliter using the 

following formula: 

lbs. / bu. x 1.287 = kilograms per hectoliter
Grain Grading Primer Chapter 2: Canola

October 2016

Page 2 - 22

Determine Grade Designation

After completing the analysis, compare the results with the limits for each grade factor. The 

factor with the lowest grade designation determines the grade assigned to the sample. 

Or Better

The Official U.S. Standards for Grain provide an optional grade designation, commonly 

referred to as “or better.” Upon request of the applicant, barley may be certified as U.S. No. 

2 or better, U.S. No. 3 or better, etc. An “or better” grade designation cannot be applied to 

U.S. No. 1 grade designation.

Documenting the Grade

Use the following guide for documenting the assigned grade.

• First write the letters “U.S.”,

• Then the abbreviation “No.” and the number of the grade or the words “Sample grade”,

• Followed by the words “or better” when applicable,

• The word ”Canola” shall be shown next, followed by the applicable special grade(s), 

• and last show the word “dockage” and the percentage thereof to the nearest tenth 

percent.

When applicable record the words “Musty,” “Sour,” or “Commercially Objectionable Foreign 

Odor” in the “Remarks” section of the certificate.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 1

Grain Grading Primer

Chapter 3

Corn

Chapter 3: Corn
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 2

Contents

Chapter 3: Corn

Definition of Corn ...................................................................................................................3

Corn Classes...........................................................................................................................3

Basis of Determination ..........................................................................................................5

Distinctly Low Quality ............................................................................................................6

Heating ....................................................................................................................................6

Infested....................................................................................................................................7

Odor Determination ................................................................................................................7

Processing the Original Sample ...........................................................................................8

File Sample..............................................................................................................................9

Moisture Determination .......................................................................................................10

Test Weight ........................................................................................................................... 11

U.S. Sample Grade Factors .................................................................................................12

Broken Corn and Foreign Material (BCFM) .......................................................................12

Processing the BCFM-Free Work Sample ..........................................................................13

Class......................................................................................................................................14

Visual Reference Images (VRI) ...........................................................................................15

Damaged Kernels .................................................................................................................16

Types of Corn Damage .........................................................................................................16

Flint Corn and Flint and Dent Corn .....................................................................................22

Waxy Corn .............................................................................................................................23

Official Criteria .....................................................................................................................24

Grade Designation ...............................................................................................................25

Optional Grade Designation ...............................................................................................25

Documenting the Grade .......................................................................................................26
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 3

Definition of Corn

Corn is defined as:

Grain that consists of 50 percent or more of whole kernels 

of shelled dent corn and/or shelled flint corn (Zea mays 

L.) and may contain not more than 10.0 percent of other 

grains for which standards have been established under 

the United States Grain Standards Act.

Corn Classes

Corn is divided into three classes based on color: Yellow 

corn, White corn, and Mixed corn. 
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 4

Grade Requirements

Each class is divided into five U.S. numerical grades and U.S. Sample Grade. 

Special grades are provided to emphasize special qualities or conditions affecting the value 

and are added to and made a part of the grade designation. They do not affect the numerical or 

sample grade designations.

Grades and Grade Requirement Chart

CORN

Grade

Minimum Limits of - Maximum Limits of -

Test weight per 

bushel

(pounds)

Heat-Damaged 

kernels

(percent)

Damaged kernels 

total

(percent)

Broken Corn and 

Foreign material (percent)

U.S. No. 1 56.0 0.1 3.0 2.0

U.S. No. 2 54.0 0.2 5.0 3.0

U.S. No. 3 52.0 0.5 7.0 4.0

U.S. No. 4 49.0 1.0 10.0 5.0

U.S. No. 5 46.0 3.0 15.0 7.0

U.S. Sample Grade: 

U.S. Sample Grade is corn that: 

(a) Does not meet the requirements for grades U.S. No.1, 2, 3, 4, or 5; or 

(b) Contains stones which have an aggregate weight in excess of 0.1 percent of the 

sample weight, 2 or more pieces of glass, 3 or more crotalaria seeds (Crotalaria spp.), 

2 or more castor beans (Ricinus communis L.), 4 or more particles of an unknown 

foreign substance(s) or a commonly recognized harmful or toxic substance(s), 8 or 

more cockleburs (Xanthium spp.) or similar seeds singly or in combination, or animal 

filth in excess of 0.20 percent in 1,000 grams; or 

(c) Has a musty, sour, or commercially objectionable foreign odor; or 

(d) Is heating or otherwise of distinctly low quality. 
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 5

Basis of Determination

The “Basis of Determination” establishes the rules for testing/analyzing all factors. Do not 

analyze any factor until the basis for making the determination is known.

BASIS OF DETERMINATION

Lot as a Whole

Factors Determined Before 

the Removal of Broken Corn 

and Foreign Material

Factors Determined After 

the Removal of Broken Corn 

and Foreign Material

Distinctly low quality 

Heating 

Infested 

Odor 

Distinctly low quality

Heating 

Infested 

Kind of Grain 

Moisture 

Odor 

Stones 

Test Weight 

U.S. Sample Grade factors

Class 

Damaged kernels

Flint corn 

Flint and dent corn 

Heat-damaged kernels 

Odor 

Waxy

The determination of Distinctly Low Quality (DLQ) is made on the basis of the lot as a whole at the 

time of sampling when a condition exists that may or may not appear in the representative sample 

and/or the sample as a whole.

Each determination of rodent pellets, bird droppings, other animal filth, broken glass, castor 

beans, cockleburs, crotalaria seeds, dockage, garlic, live insect infestation, large stones, moisture, 

temperature, and unknown foreign substance(s), and a commonly recognized harmful or toxic 

substance(s) is made on the basis of the sample as a whole. When a condition exists that may not 

appear in the representative sample, the determination may be made on the basis of the lot as a 

whole at the time of sampling according to procedures prescribed in FGIS instructions.

Each determination of class, damaged kernels, heat-damaged kernels, waxy corn, flint corn, and 

flint and dent corn is made on the basis of the grain after the removal of the broken corn and 

foreign material. Other determinations not specifically provided for under the General Provisions 

are made on the basis of the grain as a whole, except the determination of odor is made on either 

the basis of the grain as a whole or the grain when free from broken corn and foreign material.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 6

Distinctly Low Quality

Consider corn DLQ when it is obviously of inferior quality and the 

existing grade factors or guidelines do not accurately reflect the 

inferior condition. 

Use all available information to determine whether the corn is DLQ. 

This includes a general examination of the corn during sampling 

and an analysis of the obtained sample. 

Corn containing two or more stones, pieces of glass, pieces of 

concrete, or other pieces of wreckage or debris which are visible 

to the sampler but are too large to enter the sampling device is 

considered DLQ. 

Corn that is obviously affected by other unusual conditions which 

adversely affect the quality of the corn and cannot be properly 

graded by use of the grading factors specified or defined in the 

standards is considered distinctly low quality.

Heating

Corn developing a high temperature from fermentation is considered heating. Heating corn, in its 

final stages, will usually have a sour or musty odor. Care should be taken not to confuse corn that 

is heating with corn that is warm and moist because of storage in bins, railcars, or other containers 

during hot weather.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 7

Infested

Infested corn is corn that is infested with live weevils or other live insects injurious to stored grain.

The presence of any live weevil or other live insects injurious to stored grain found in the work 

sample indicates the probability of infestation and warns that the corn must be carefully examined 

to determine if it is infested. In such cases, examine the work sample and the file sample before 

reaching a conclusion as to whether or not the corn is infested. Do not examine the file sample if 

the work sample is insect free.

INSECT INFESTATION

Samples meeting or exceeding any one of these tolerances are infested: 

2 lw, or 1 lw + 5 oli, or 10 oli

1,000-gram representative sample1

(+ file sample if needed) Lot as a Whole (Stationary) Online Sample (In-Motion)2

Submitted samples

Probed lots 

D/T sampled land carriers

Probed lots (at time of sampling) Railcars under the Cu-sum 

Subsamples for Sacked Grain lots 

Components for Bargelots3

Components for Shiplots3

1

 Examine work portion and file sample if necessary. Do not examine file sample if work portion is insect free.

2

 Minimum sampling rate is 500 grams per 2,000 bushels. 

3

 Minimum component size is 10,000 bushels. 

Key: lw = live weevil, oli = other live insects injurious to stored grain

Odor Determination

Basis of Determination. Determine odor on evidence obtained at the time of sampling or on the 

sample either before or after the removal of broken corn and foreign material.

When grain has a “distinct” odor, it should 

be graded musty, sour, or commercially 

objectionable foreign odor.

The definition of “distinct”, when it 

pertains to odor, is not the intensity of the 

off-odor, but the presence of the off-odor. 

The consensus approach is not required 

if no odor, or a distinct odor, is present. 
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 8

Musty odors indicate the presence of fungal activity in the grain and are generally characterized 

as an earthy smell.

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are often 

characterized as an acrid, boot pit or pigpen smell.

Commercially Objectionable Foreign Odor (COFO) are odors, except smut and garlic odors, 

foreign to grain that render it unfit for normal commercial usage. Sources of COFO include 

fumigants, oil products, smoke, fertilizer, weeds, decaying animal or plant matter, etc. 

Processing the Original Sample

The Boerner Divider reduces the size of a grain sample while maintaining the representativeness 

of the original sample. Use the Boerner divider, or a divider that gives equivalent results, when 

reducing a sample to the portion size required for a specific test/analysis.

When dividing the original sample the first 

pass through the divider will result in two 

equal portions. 

• One portion is set aside as a “file sample”. 

• One portion is the “work portion” which is 

reduced down to smaller work portions 

for use in determining required tests and 

analysis specific to the type of grain being 

graded.

 File Sample Work Portion

Operating Procedures 

• Check the divider for condition and cleanliness

• Close the hopper valve

• Place empty collection pans under the discharge spouts

• Pour the sample into the hopper

• Open the valve quickly. For large samples, feed more grain into the hopper during the dividing 

process
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 9

File Sample

A “file sample” is a representative sample or representative portion of a sample that is retained for 

a specified period of time for reference or review purposes. File samples should be of sufficient 

size to accommodate subsequent examinations or analysis. The file sample shall be an unworked 

portion (if available) of the representative sample used for the inspection. The worked portion may 

be retained as the final file only when insufficient sample is available for an unworked file sample. 

Keep all samples in sealed moisture proof containers if they cannot be tested within approximately 

15 minutes. Do not use paper bags, fiber cartons, or similar containers that allow moisture losses. 

Use metal cans, plastic containers, and plastic bags to preserve the sample integrity. Do not file 

samples with paper identification inserted in the grain. Paper absorbs moisture and lowers the 

moisture of the grain.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 10

Moisture Determination

Water content in grain as determined by an approved device according to procedures 

prescribed in FGIS instructions.

Basis of Determination. Determine moisture before the removal of dockage on a portion of 

approximately 650 grams.

The user interfaces are slightly different for the two UGMA compatible moisture meters. Use 

the keypad to choose the type of grain to analyze. 

Fill the hopper and press the load key to start the test cycle. After the moisture analysis 

is complete observe the result on the display, record it and reclaim the sample from the 

discharge tray. 

For additional information, refer to the GIPSA Moisture Handbook.

GAC2500-UGMA Perten AM 5200-A
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 11

Test Weight

Test weight per bushel is the weight per Winchester bushel (2,150.42 cubic inches) as 

determined using an approved device. The determination for test weight is made on a 

portion of sufficient quantity to overflow the kettle. 

General Operating Procedures

1. Level and balance the test weight per 

bushel apparatus.

2. Close the hopper valve.

3. Pour the work sample into the hopper.

4. Center the hopper over the kettle.

5. Fill the kettle by opening the hopper 

valve quickly.

6. Move the hopper all the way to the 

left before proceeding. Do not jar the 

apparatus. Jarring could cause 

inaccurate results.

7. Using a standard stroker, stroke the 

kettle by holding the stroker in both 

hands with the flat sides in a vertical 

position. Level the grain in the kettle 

by making three full length, zigzag 

motions with the stroker.

8. Place an empty sample pan or the test weight kettle on the scale and zero the scale. 

Pour the sample from the kettle into the sample pan or place the filled kettle onto the 

scale as appropriate. Read the result from the test weight mode selected.

9. Record the test weight per bushel on the work record. 
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 12

U.S. Sample Grade Factors

Basis of Determination. Determine U.S. Sample Grade criteria before the removal of 

broken corn and foreign material based on a work portion of 1,000 to 1,050 grams.

Consider identifiable pieces of grain, processed grain products such as soybean meal, 

sorghum grits, corn meal, bulgur, etc., or feed pellets in grain as foreign material. 

Unidentifiable materials or material unrelated to grain shall function as “unknown foreign 

substance”. 

Toxic Seeds

(Crotalaria)

Broken Corn and Foreign Material (BCFM)

BCFM is all matter that passes readily through a 12/64 round-hole sieve and all matter other 

than corn that remains in the sieved sample after sieving. 

Animal Filth

The determination of BCFM is performed in two steps .

A mechanical separation of BCFM is made using a 

Carter Dockage Tester to remove the larger and finer 

particulate matter from the sample. 

The mechanically cleaned sample is then 

handpicked to remove any remaining similarly sized 

foreign material from the sample. 

To avoid repeating operations, check the material 

found in the BCFM sieve catch pans for live weevils 

and other live insects injurious to stored grain, 

stones, distinctly low quality, and other sample grade 

factors. 

Live weevils, other live insects injurious to stored grain, and sample grade factors are 

considered FM but, when present in sufficient quantities, are considered in the determination 

of U.S. Sample Grade and/or the special grade “Infested.”
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 13

Procedure for Determining BCFM

AIR COLLECTION PAN AIR (1)

HOPPER

RIDDLE (no riddle)

TOP SIEVE (No. 3)

RIDDLE

COLLECTION PAN

BOTTOM COLLECTION PAN

TOP SIEVE

COLLECTION PAN

MIDDLE SIEVE

COLLECTION PAN

BOTTOM SIEVE

COLLECTION PAN

FEED CONTROL (10)

MIDDLE SIEVE (no sieve)

BOTTOM SIEVE (no sieve)

1,000 to 1,050 Work Portion

Step 1: Carter Dockage 

Tester

a. Set the air control to 1

and the feed control to 10.

b. Insert the No. 3 sieve in 

the top sieve carriage

c. Run 1,000 – 1,050 grams 

through the dockage 

tester.

Step 2: Handpick 

a. Remove all matter other 

than corn, including 

sweet corn, blue corn, 

and popcorn from the 

mechanically cleaned 

portion.

b. Combine the mechanically 

separated and 

handpicked BCFM.

Processing the BCFM-Free Work Sample

After determinations have been made on the work portion prior to the removal of BCFM 

and then processed to remove BCFM, divide the BCFM-free work portion into the following 

approximate analytical portion sizes for the factors listed. 

APPROXIMATE ANALYTICAL PORTION SIZES

Factors Grams

Class

Damaged kernels

Flint corn

Flint and dent corn

Heat-damaged kernels

250 

250

250

250

250
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 14

Class

Determine the class of corn by the color characteristics of the kernels. 

Yellow Corn is corn that is yellow-kerneled and contains not more than 5.0 percent of 

corn of other colors. Yellow kernels of corn with a slight tinge of red are considered Yellow 

corn.

White Corn is corn that is white-kerneled and contains not more than 2.0 percent of 

corn of other colors. White kernels of corn with a slight tinge of light straw or pink color are 

considered White corn.

Mixed Corn is corn that does not meet the color requirements for either of the classes 

Yellow corn or White corn and includes white-capped Yellow corn.

When determining the class of corn, consider “Indian Corn” as “Corn of other Colors.”

Record the percentage of corn of other colors on the certificate to the nearest tenth percent. 

When certificating Mixed corn, record the percentage of the mixture, in the order of 

predominance, in the “Remarks” section to the nearest tenth percent.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 15

Visual Reference Images (VRI) 

Because of the subjectivity involved in determining damage and other criteria, it is critical that 

visual references are available to ensure that interpretations are uniformly and consistently 

applied throughout the national system. 

Visual Reference Images provide a basis for communicating the minimum “line” for various 

types of damage and other visually determined criteria.

For complete inventory and description of the VRI visit our website.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 16

Insect Damage

Damaged Kernels

Kernels and pieces of corn kernels that are badly ground-damaged, badly weather-damaged, 

diseased, frost-damaged, germ-damaged, heat-damaged, insect-bored, mold-damaged, 

sprout-damaged, or otherwise materially damaged.

Types of Corn Damage

A kernel of corn is considered damaged for inspection and grading purposes when the 

damage is distinctly apparent and of such character as to be recognized as damaged for 

commercial purposes.

Cob Rot Damage

Sprout Damage
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October 2016

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Purple plumule IS NOT damage. The condition (light to dark purple discoloration) is due to 

a genetic or varietal characteristic and is restricted to the plumule area (center of germ). 

NOTE: The outward appearance is similar to blue-eye mold. Consequently, it may be 

necessary to gently lift/remove the germ cover to make an accurate determination.

Cob Rot Damage

A germ affected with blue-eye mold, regardless of the size of the mold is a damaged kernel. 

If mold is distinct, it is not necessary to open or scrape kernel. When necessary, carefully 

lift the germ cover to avoid destroying evidence of mold. NOTE: Do not confuse blue-eye 

mold with purple plumules. Any amount of mold that penetrates the seed coat of the kernel is 

considered damage (e.g., crown, tip, sides, or back).

Purple Plumule (Not Damage)

Blue-Eye Mold Damage

A distinct discoloration or rotting caused by a fungus that attacks ears of weakened plants. 

Since the damage is distinct, it is unnecessary to open the kernel for examination. NOTE: If 

kernels do not meet the interpretation, it may be necessary to open the kernels to determine 

if the kernels are otherwise damaged.
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October 2016

Page 3 - 18

Drier Damage

Kernels which have a discolored, wrinkled, and blistered appearance; or which are puffed 

and/or swollen and slightly discolored and often have damaged germs; or whose seed coats 

are peeling off and are slightly discolored; or whose seed coat is peeling off (or has already 

peeled off), having a crazed or checked appearance.

Heat Damage (Yellow)

Kernels which are materially discolored from spoilage. The discoloration originates from 

the germ area and continues through the sides and back of the kernel (continuous band). 

Provided the band is continuous, there is no minimum width requirement.

]

Heat Damage (Drier)

Kernels of corn which are often puffed or swollen and materially discolored by external heat 

from artificial drying methods. NOTE: The entire kernel must be discolored to this intensity to 

be heat damage. This applies to all classes of corn.
Grain Grading Primer Chapter 3: Corn

October 2016

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Germ Damage

Kernels of corn which are damaged by respiration or heat, but which are not materially 

discolored, shall be considered damaged. Kernels with germ areas discolored to the degree 

shown or worse are considered damage.

Heat Damage (White)

Kernels which are materially discolored from spoilage. The discoloration originates from 

the germ area and continues through the sides and back of the kernel (continuous band). 

Provided the band is continuous, there is no minimum band width requirement.

Insect Damage

Whole or broken kernels with obvious weevil-bored holes or which have evidence of boring 

or tunneling (tracings) indicating the possible inner presence of insects, insect webbing, or 

insect refuse. NOTE: Do not probe into or further expose weevil-bored holes or tunneling. 

Weevil bored holes that are completely visible and are free of insect webbing and/or refuse 

are sound.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 20

Mold Damage

Whole or broken kernels which contain any amount of mold on the exposed part of the kernel 

are considered damage. NOTE: Do not confuse mold with dirt. Mold occurs in many colors.

Not Damage (Dirt)

Whole or broken kernels which have dirt on the exposed part of the kernel.

NOTE: Do not confuse dirt with mold.

Silk Cut

Kernels which contain any amount of mold in the silk cut are damaged. Kernels which 

contain clean silk cuts and are otherwise undamaged are sound kernels.
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October 2016

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Surface Mold (Blight)

Kernels which have a mold, caused by corn leaf blight, that appears to be only on the surface 

but actually penetrates the seed coat. Kernels which contain surface mold (blight) on one 

or both sides equal to or greater than that shown on both kernels are considered as surface 

mold (blight) damage.

Surface Mold (More than Slight)

Kernels of corn which contain surface mold in any area or combination of areas equal to or 

greater than shown on the VRI. 

Mold Damage (Pink Epicoccum)

A germ affected with mold, regardless of the size of the mold, is a damaged kernel. If the 

mold is distinct, it is not necessary to open or scrape kernel. If opening kernel is necessary, 

lift germ cover carefully to avoid destroying evidence of mold. NOTE: Do not confuse pink 

epicoccum with the reddish genetic characteristics found in some corn hybrids.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 22

Sprout Damage

Kernels which are sprouted or show evidence of sprouting are considered damage. NOTE: 

Anytime the sprout extends beyond the germ area, regardless of whether it actually breaks 

through the seed coat or not, the affected kernel is considered damaged.

Flint Corn and Flint and Dent Corn

Flint Corn is corn that consists of 95 percent or more of Flint corn.

A kernel of Flint corn normally has a rounded crown and is usually smaller than a dent kernel. 

Flint and Dent Corn is corn that consists of a mixture of Flint and Dent corn containing more 

than 5.0 percent but less than 95 percent of Flint corn.

A kernel of Dent corn is normally characterized by a distinct depression or dent in the crown 

of the kernel.

In mixtures of Flint and Dent corn, there is frequently a difference in the color of the two 

types. The shape of the kernel, the size, the texture, and the color characteristics are used in 

making a determination in mixtures of Flint and Dent corn.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 23

Waxy Corn

Waxy Corn is corn that consists of 95 percent or more waxy corn according to procedures 

prescribed in FGIS instructions. 

Basis of Determination. When corn appears to contain 95 percent or more waxy kernels, 

test the sample to determine whether the special grade Waxy applies. Use exactly 100 

kernels cut out of a 35-gram portion of BCFM-free corn.

When determining class for a sample of corn designated Waxy, apply the following 

guidelines: For the special grade Waxy, the requirement of white kernels of corn with a 

slight tinge of light straw is not applicable; however, kernels which are “slightly yellow” are 

considered as corn of other colors. 

All other color requirements remain in effect for all classes of Waxy corn. 

Slightly Yellow in (White Waxy) Corn

Procedure for Testing Waxy Kernels of Corn

NOTE: For required materials and equipment, refer to Grain Inspection Handbook Book II - 

Chapter 1 General Information - Section 1.18

CAUTION - Wear safety equipment. spray iodine solution only in a well ventilated 

area or within the working area of a laboratory hood. To prevent staining tables and 

surrounding areas, place the petri dish on a covered surface before spraying.

1. Pour 30 ml of the iodine stock solution into a spray bottle and dilute it with 30 ml of 

distilled water.

2. Cut each of the whole kernels lengthwise (tip to crown) or across the top exposing the 

starch in the endosperm. Place one-half of each kernel into a petri dish and discard the 

other half.

3. Carefully spray (do not soak) all the cut kernels with the iodine solution.
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 24

4. Approximately 1 to 3 minutes after spraying, the starch of the Waxy corn kernels will 

turn a red or reddish-brown color. The starch of nonwaxy kernels will turn a blue or violet 

color. Consider samples with 95 kernels (95 percent) turning red or reddish-brown color 

as Waxy corn. 

Waxy & Non-Waxy

Official Criteria 

Stress Crack Analysis is determined only upon request. It does not affect the grade 

designation.

Stress crack analysis is determined on the basis of a predetermined number of whole 

kernels. Do not include kernels that are broken, chipped, or cracked (i.e., a ruptured seed 

coat), or which otherwise limit the ability to identify stress cracks, e.g., waxy or discolored 

kernels. Use a divider to obtain the appropriate analytical portion size based on the 

requested service. Removal of broken corn and foreign material prior to obtaining the 

analytical portion may facilitate whole kernel selection.

1. For percent total stress crack analysis, obtain approximately 25 grams to select 

50 whole kernels. Multiply the number of stressed kernels by 2 before reporting.

2. For percent single, double, and multiple stress crack analysis, obtain approximately 

50 grams to select 100 whole kernels. Report number of stressed kernels as obtained.

NOTE: The above portion sizes are the minimum required. Upon request, larger portion 

sizes are permitted. If a larger portion size is used, adjust test results as appropriate before 

reporting.

3. Upon request, separate and count the number of kernels in the three stress crack 

categories: single, double, and multiple stress cracks. Visually inspect whole kernels on 

a light board for internal narrow cracks in the endosperm as follows:

a. Place kernels on the light board with germ side down. Visually inspect each kernel 

for stress cracks and separate stressed kernels.

b. Turn remaining kernels germ 

side up. Visually inspect each 

kernel for stress cracks and 

separate stressed kernels.

c. Count the total number of 

stressed kernels.
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October 2016

Page 3 - 25

Presence of Waxy Kernels procedure is applicable only for determining the presence of 

waxy corn and does not replace the procedure for determining the special grade “Waxy.”

A representative portion of at least 35 grams of corn on the basis of the sample as a whole.

1. Pour 30 ml of the iodine stock solution into a spray bottle and dilute it with 30 ml of 

distilled water.

2. Coarse grind the 35 gram sample.

NOTE: A Romer Mill – Model 2A, Bunn Grinder, or equivalent, must be used to coarsely 

grind samples. The grinder must be adjusted so that 80 percent or more of the sample 

remains on top of an 8/64 round-hole sieve and that all kernels are broken open to 

expose the endosperm.

3. Carefully spray (do not soak) the entire sample with the iodine solution. If an 8/64 sieve 

was used to separate the broken kernels from the fine material, then spray only the 

material that remains on top of the sieve.

4. Shortly after spraying the kernels (approximately 1 to 3 minutes), the starch of waxy 

corn kernels will turn a red or reddish-brown color. The starch of nonwaxy kernels will 

turn a blue or violet color. 

5. Analyze the sprayed kernels to determine if any waxy kernels are present. If a single 

kernel is determined to be “waxy”, consider the sample as positive for the presence of 

waxy corn, otherwise, the sample is negative for waxy kernels.

Grade Designation

After completing the analysis, compare the results with the limits for each grade factor. The 

factor with the lowest grade designation determines the grade assigned to the sample. 

Optional Grade Designation

The Official U.S. Standards for Grain provide for an optional grade designation, commonly 

referred to as “or better.” Upon the request of an applicant, corn may be certified as U.S. No. 

2 or better, U.S. No. 3 or better, etc. An “or better” grade designation cannot be applied to a 

U.S. No. 1 grade designation.

Example: U.S. No. 3 or better Yellow Corn
Grain Grading Primer Chapter 3: Corn

October 2016

Page 3 - 26

Documenting the Grade

Use the following guidelines when documenting the grade.

• The letters “U.S.”

• The abbreviation “No.” and the number of the grade or the words “Sample Grade”

• The words “or better” when applicable

• The name of the class and kind of grain

• The special grade “Flint” when applicable 

(Example: U.S. No. 3 Yellow Corn, Flint)

• The special grade “Flint and Dent”, (when applicable) along with the approximate 

percentage of flint corn

(Example: U.S. No. 2 Yellow Corn, Flint and Dent, Flint Corn 35 percent)

• The special grade “Infested” when applicable

(Example: U.S. No. 2 Yellow Corn, Infested)

• The special grade “Waxy” (when applicable) shall be shown last in the grade designation.

(Example: U.S. No. 1 White Corn, Waxy)

When more than one special grade applies, list them in alphabetical order.

When certificating Mixed corn, record the percent of each corn in order of predominance in 

the “Remarks” section to the nearest tenth percent.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 1

Chapter 4: Flaxseed

Grain Grading Primer

Chapter 4

Flaxseed
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 2

Contents

Chapter 4: Flaxseed

Flaxseed Definition.................................................................................................................4

Grade Requirements ..............................................................................................................5

Heating ....................................................................................................................................5

Distinctly Low Quality ............................................................................................................6

Processing the Original Sample ...........................................................................................6

Boerner Divider.......................................................................................................................7

File Sample..............................................................................................................................8

Use Moisture Proof Containers .............................................................................................8

Check for Odor .......................................................................................................................9

Sample Grade Criteria ..........................................................................................................10

Dockage.................................................................................................................................10

Determine Dockage .............................................................................................................. 11
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October 2016

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Reclaim.................................................................................................................................. 11

Stones.................................................................................................................................... 11

Test Weight ...........................................................................................................................13

Moisture Determination .......................................................................................................14

Dividing the Work Sample ...................................................................................................15

Handpicked Dockage ...........................................................................................................16

Computing Dockage .............................................................................................................16

Dockage Example .................................................................................................................16

Damaged Kernels .................................................................................................................17

Grade Designations..............................................................................................................18

Or Better................................................................................................................................19

Documenting the Grade .......................................................................................................19
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 4

Flaxseed Definition

Flaxseed is defined as grain that before the removal of dockage, consists of 50 percent or 

more of common flaxseed and not more than 20 percent of other grains for which standards 

have been established under the United States Grain Standards Act and which, after the 

removal of dockage, contains 50 percent or more of whole flaxseed.

Normally, a visual appraisal of the sample is sufficient to determine if the sample meets the 

definition for flaxseed. However, if an analysis is necessary, make the determination before 

the removal of dockage on a representative portion of 25 grams. There are no classes, 

subclasses, or special grades in flaxseed.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 5

Grade Requirements

Flaxseed is divided into two numerical grades and U.S. Sample grade.

The factors affecting flaxseed grades include: test weight, heat damaged kernels, and total 

damage.

U.S. Sample grade is flaxseed that does not meet the requirements for the grades U.S. 

Numbers. 1 or 2 or contains stones, glass, crotalaria seeds, castor beans, an unknown 

foreign substance or a commonly recognized harmful or toxic substance, rodent pellets, bird 

droppings, or other animal filth; or has a musty, sour, or commercially objectionable foreign 

odor; or is heating or otherwise of distinctly low quality.

FLAXSEED

Grade

Minimum Limits of - Maximum Limits of -

Test weight per bushel 

(pounds)

Heat-Damaged kernels

(percent)

Damaged kernels total

(percent)

U.S. No. 1 49.0 0.2 10.0

U.S. No. 2 47.0 0.5 15.0

U.S. Sample Grade is flaxseed that: 

(a) Does not meet the requirements for grades U.S. No. 1, or 2; or 

(b) Contains 8 or more stones which have an aggregate weight in excess of 0.2 percent of the 

sample weight, 2 or more pieces of glass, 3 or more crotalaria seeds (Crotalaria spp.), 2 or 

more castor beans (Ricinus communis L.), 4 or more particles of an unknown foreign 

substance(s) or a commonly recognized harmful or toxic substance(s), 10 or more rodent 

pellets, bird droppings, or equivalent quantity of other animal filth per 1 1/8 to 1 . quarts of 

flaxseed, or 

(c) Has a musty, sour, or commercially objectionable foreign odor (except smut or garlic); or 

(d) Is heating or otherwise of distinctly low quality.

Heating

Flaxseed developing high temperature from excessive respiration due to microbial activity 

(fermenting), insect infestation, or sprouting is considered heating. Heating flaxseed, in its 

final stages, will usually have a sour or musty odor. Care should be taken not to confuse 

flaxseed that is heating with flaxseed that is warm because of storage in bins, railcars, or 

other containers during hot weather. 

Determine heating on evidence obtained at the time of sampling or on the basis of the 

sample as a whole. Grade heating flaxseed U.S. Sample Grade and record the word 

“Heating” in the “Remarks” section of the certificate.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 6

Distinctly Low Quality

Consider flaxseed distinctly low quality when it is obviously of inferior quality and the existing 

grading factors or guidelines do not properly reflect the inferior condition. Use all available 

information to determine whether the flaxseed is of distinctly low quality. This includes 

a general examination of the flaxseed during sampling and an analysis of the obtained 

sample(s).

Flaxseed containing two or more stones, pieces of glass, pieces of concrete, and/or other 

pieces of wreckage or debris which are visible to the sampler but are too large to enter the 

sampling device is considered distinctly low quality.

Flaxseed that is obviously affected by other unusual conditions which adversely affect the 

quality of the flaxseed and cannot be properly graded by use of the grading factors specified 

or defined in the standards is considered distinctly low quality.

Grade distinctly low quality flaxseed as U.S. Sample Grade. Record the words “Distinctly Low 

Quality” and the reason(s) why in the “Remarks” section of the certificate.

Processing the Original Sample

The first step in grading a flaxseed sample is to use a Boerner divider to reduce the original 

sample into a file sample and a work portion. 

The Boerner divider reduces the size of a grain sample while maintaining its 

representativeness.

File Work
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 7

Boerner Divider

The Boerner divider reduces the size 

of a grain sample while maintaining 

its representativeness. Each pass of 

the sample through the divider splits 

the sample into two equal portions. 

The Boerner Divider, consists of a 

hopper, inverted cone, and a series 

of baffles directing the grain into two 

collection pans. As the valve or gate 

at the base of the hopper is opened, 

gravity carries the grain over the cone, 

which serves as a surface by which 

the kernels can separate into a single 

layer. Arranged in a circle at the base 

of the cone are a series of baffles 

forming alternate channels and spaces 

of equal width. They are arranged in a 

circle at their summit and are directed 

inward and downward, the channels 

leading to one spout and the spaces 

to an opposite spout. Each kernel has an equal chance of falling into a channel or a space, 

resulting in two nearly identical portions of the original sample.

• When Operating the Boerner Divider:

• Check the divider for condition and cleanliness.

• Close the hopper valve.

• Place empty collection pans under the discharge spout.

• Pour the sample into the hopper.

• Open the valve quickly.

For larger samples, feed more grain into the hopper during the dividing process.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

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File Sample

A “file sample,” is a representative sample 

or representative portion of a sample that 

is retained for a specified period of time for 

reference or review purposes.

File samples shall be of sufficient size to 

accommodate subsequent examinations or 

analysis. 

The file sample shall be an unworked portion (if 

available) of the representative sample used for 

the inspection. 

The worked portion may be retained as the final 

file only when insufficient sample is available for 

an unworked file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, 

or similar containers that allow moisture 

losses. Use metal cans, plastic containers, 

and plastic bags to preserve the sample 

integrity. 

Do not file samples with paper 

identification inserted in the grain. Paper 

absorbs moisture and lowers the moisture 

of the grain.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 9

Check for Odor

Determine odor on evidence obtained at 

the time of sampling or on the sample either 

before or after the removal of Dockage. Odors 

are classified as OK, Musty, Sour, or COFO 

(commercially objectionable foreign odors). 

Musty odors indicate the presence of 

fungal activity in the grain and are generally 

characterized as an earthy smell.

Sour odors indicate that the grain is fermenting 

due to microbial activity. Sour odors are often 

characterized as an acrid, boot pit or pigpen 

smell.

Commercially objectionable foreign odors are odors foreign to grain that render it unfit for 

normal commercial usage.

When heat-damaged kernels are present, flaxseed gives off an odor very similar to smoke. 

Flaxseed containing a “smoke” odor is considered as having a “sour” odor unless evidence 

of a fire-burnt material is present in the lot or the original sample. If evidence of a fire-burnt 

material is present in the lot or the sample, the smoke odor is considered a commercially 

objectionable foreign odor.

The inspector is responsible for making the final determination for all odors. However, a 

consensus of experienced inspectors should be used, whenever possible, on samples 

containing marginal odors. 

Grade flaxseed containing a “distinct” musty, sour, or commercially objectionable foreign odor 

as U.S. Sample grade. Record the words “Musty,” “Sour,” or “Commercially Objectionable 

Foreign Odor” in the “Remarks” section of the certificate. 

Fumigant or Insecticide Odors

Fumigant or insecticide odors are considered 

commercially objectionable foreign odors if they 

linger and do not dissipate. When a sample of 

flaxseed contains a fumigant or insecticide odor 

that prevents a determination as to whether any 

other odor(s) exists, allow the work portion to 

aerate in an open container for 4 hours, or less, if 

the odor dissipates in less time.

Consider the sample as having a commercially 

objectionable foreign odor if the fumigant or 

insecticide odor persists after 4 hours.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 10

Sample Grade Criteria

Determine U.S. Sample grade criteria, except for stones, before the removal of dockage 

based on the work portion of approximately 1000 grams. U.S. Sample grade is flaxseed that 

contains:

• 2 or more pieces of glass, 

• 3 or more crotalaria seeds, 

• 2 or more castor beans, 

• 4 or more particles of an unknown foreign substance(s), or a commonly recognized 

harmful or toxic substance(s), 

• 10 or more rodent pellets, bird droppings, or equivalent quantity of other animal filth per 

1000 grams of flaxseed; or 

• is heating or otherwise of distinctly low quality.

When flaxseed is graded “U.S. Sample grade” record the reason why in the “Remarks” 

section of the certificate. Record count factors to the nearest whole number. 

Dockage

Determine dockage on a portion of 1,000 - 1,050 grams.

Dockage is all matter other than flaxseed that can be removed from the original sample by 

use of the Carter Dockage Tester. Also, underdeveloped, shriveled, and small pieces of 

flaxseed kernels removed in properly separating the material other than flaxseed and that 

cannot be recovered by properly re-screening or re-cleaning.

Record the word “Dockage” and the percentage on the work record in hundredths. When 

the sample contains 1 percent or more dockage, record the percentage of dockage on the 

certificate in whole percent with a fraction of a percent disregarded.

For example: 

1.00 to 1.99 percent is recorded as 1.0 percent

2.00 to 2.99 percent is recorded as 2.0 percent, etc.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 11

Determine Dockage

To determine dockage using the Carter Dockage Tester, first insert the Number 4 sieve in 

the top sieve carriage, the number 2 sieve in the middle carriage, the number 7 sieves in the 

bottom sieve carriage and the 000 riddle in the riddle carriage. Set the air to 3.5 and the feed 

control to 4. 

Next, run 1,000 - 1,050 grams through the dockage tester. 

Then, if matted lumps of flaxseed clog or kick over the riddle, remove the riddle and the No. 4 

sieve and proceed with the dockage determination. 

Finally, if the material that passes over the No. 4 sieve contains lumps of flaxseed that cannot 

be reclaimed, add this portion to the mechanically cleaned flaxseed. 

Reclaim

Using an approved hand sieve, reclaim the flaxseed passing over the No. 4 sieve. 

When the material contains large-sized flaxseed, sieve with a 0.064 by 3/8 inch sieve using 

30 strokes. 

When the material contains small-sized flaxseed, sieve with a 3/64 by 3/8 inch or a 3/64 by 

11/32 inch sieve using 30 strokes. 

Using an approved hand sieve, reclaim the flaxseed passing over the No. 7 sieve. Sieve with 

a 3/64 by 11/32 inch sieve or a 3/64 by 3/8 inch sieve using 30 strokes.

Combine the three mechanically cleaned portions.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 12

Dockage Procedure

1,000-1,050 

gram sample

Air #3.5

Feed #4

#4 

Top 

Sieve

#7

Bottom

Sieve

#2

Middle 

Sieve

000 Riddle

Air Collection Pan

DKG #1

DKG #2

Reclaim

Flaxseed 

Over No. 4

Hand Sieve

Mech Cleaned

Flaxseed #3 

DKG # 5 

Mech. Cleaned 

Flaxseed #1

Reclaim

Flaxseed

Over No. 7

Hand Sieve

Mech Cleaned

Flaxseed #2

DKG # 4 

Bottom Collection Pan

DKG #3

Combine

Mechanically Cleaned 

Flaxseed Nos. 1, 2, and 3

15 gram Subportion

Hand separate Flaxseed from 

Non-flaxseed

DKG # 6 Flaxseed

Total DKG = 1+2+3+4+5+6 
Grain Grading Primer Chapter 4: Flaxseed

October 2016

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Stones

Determine stones on the dockage-free portion. 

Consider identifiable pieces of grain, processed grain products such as soybean meal, 

sorghum grits, corn meal, bulgur, etc., or feed pellets in grain as dockage. Unidentifiable 

materials or material unrelated to grain shall function as “unknown foreign substance.“

Flaxseed that contains 8 or more stones which have an aggregate weight in excess of 0.2 

percent of the sample weight, is U.S. Sample grade.

Test Weight

Test weight is the weight per Winchester 

bushel or 2,150.42 cubic inches.Determine 

test weight on a portion of sufficient quantity 

to overflow the kettle. 

Record test weight results on the work record 

as displayed on the electronic scale or in 

whole and half pounds. Disregard fractions 

of a half-pound. Record the test weight on the 

certificate in whole and half pounds. 

If requested, convert the pounds per bushel 

result to kilograms per hectoliter using the 

formula pounds per bushels times 1.287 

equals kilograms per hectoliter and record in 

the “Remarks” section in whole and tenths. 

lbs./bu. X 1.287 = kg/hl

Position the hopper over the center of the kettle, making sure the hopper valve is closed. 

Pour grain into the hopper. 

Open the valve allowing the grain to overflow the kettle. Once the hopper is clear of grain 

move the hopper to the side. 

With a rounded edge striker, place it on the edge of the kettle and move the striker in three 

zigzag motions across the kettle leveling the grain. 

Move the kettle to a scale and record the test weight measurement.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 14

Moisture Determination

Moisture is the water content in grain.

Determine moisture on approximately 650 - 750 grams of the original sample. 

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. 

 DICKEY-john GAC2500 Perten AM5200-A 

Basically, the instruments measure the change in capacitance of two parallel plates when 

grain is placed between them. As the moisture content within the grain increases or 

decreases so does its contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.

Record the percent of moisture to the nearest tenth percent.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 15

Dividing the Work Sample

At this point, all tests required to be performed prior to the removal of dockage have been 

made and the percentage of dockage has been determined. Also, determinations for 

moisture and test weight have been performed. 

Now the work sample is ready to be cut into fractional parts for those determinations required 

to be performed after the removal of dockage. Use the Boerner divider to cut out portions for 

handpicked dockage, damage, and heat damage.

Work Sample 

1,000 – 1,050 grams 

(DKG-Free) 

1st Cut 1st Cut

2nd Cut 2nd Cut

3rd Cut

4th Cut

3rd Cut

5th Cut

4th Cut

6th Cut

5th Cut

6th Cut

Handpicked Dockage Heat Damage 

Damaged kernels
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 16

Handpicked Dockage

Handpick a 15-gram portion for material 

other than flaxseed.

Matted kernels of flaxseed are considered 

flaxseed even though portions of flax bolls 

adhere to the matted kernels.

Computing Dockage

Compute the percentage of dockage by 

adding the percentage of mechanically 

separated dockage to the percentage 

of handpicked dockage in hundredth. 

Disregard thousandths.

First divide the weight of mechanically separated dockage by the original sample weight and 

multiply by 100. This gives you the percent of mechanically separated dockage.

Subtracting the percent of mechanically separated dockage from 100 and dividing the result 

by 100 yields the change of base factor.

Then divide the weight of handpicked dockage by the weight of the handpicked portion and 

multiply the result by 100. The result is the percent of handpicked dockage.

Then multiply the percent of handpicked dockage by the change of base factor. The result is 

the adjusted percentage of handpicked dockage.

Finally add the percent of mechanically separated dockage to the adjusted percentage of 

handpicked dockage to obtain the percent of dockage.

Dockage Example

Original sample weight = 1,000 grams

Weight of mechanically separated dockage = 68.00 grams

Weight of handpicked portion = 15.30 grams

Weight of handpicked dockage = 0.55 grams

STEP 1. (68.00 ÷ 1,000) x 100 = 6.80% mechanical dockage

 

STEP 2. (100% - 6.80%) ÷ 100 = 0.93 change of base factor

STEP 3. (0.55 ÷ 15.30) x 100 = 3.59% handpicked dockage

STEP 4. 3.59 x .93 = 3.33% adjusted percentage of handpicked dockage

STEP 5. 6.80% + 3.33% = 10.13% = 10.0% dockage
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 17

Damaged Kernels

Determine damaged kernels on a mechanically 

cleaned portion of 15 grams. Damaged kernels 

are kernels and pieces of flaxseed kernels that 

are badly ground-damaged, badly weatherdamaged, diseased, frost-damaged, germdamaged, heat-damaged, insect-bored, molddamaged, sprout-damaged, or otherwise 

materially damaged. 

In general, consider flaxseed to be damaged 

for inspection and grading purposes only when 

the damage is distinctly apparent and of such 

character as to be recognized as damaged for 

commercial purposes. Green kernels of flaxseed 

which are otherwise sound are not damaged.

Record the percent of damaged kernels on the certificate to the nearest tenth percent.

“Bees Wings” Damage

Damaged flaxseed is usually characterized by a distinct discoloration, such as white, 

dark brown, or black discolorations caused by disease or by a moldy, scabby, or a dead 

appearance. 

Very thin whitish, paper like seeds of flaxseed, commonly known as “fly’s wings” or “bee’s 

wings” are also considered damaged.

Damaged by Heat

Flaxseed and pieces of flaxseed which are damaged as a result of heat but which are not 

materially discolored.
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 18

Heat-Damaged

Determine heat-damaged kernels on mechanically cleaned portion of 15 grams 

Heat-damaged kernels are kernels and pieces of flaxseed kernels that are materially 

discolored and damaged. It is necessary, in most cases, to cross-section the kernels to 

determine if the color is a chocolate color. 

Record the percentage of heat-damaged kernels on the certificate to the nearest tenth 

percent.

Grade Designations

After completing the analysis, assign a grade by comparing the results with the limits for each 

grade factor specified in the grade chart. 

The factor with the lowest grade designation determines the grade assigned to the sample. 
Grain Grading Primer Chapter 4: Flaxseed

October 2016

Page 4 - 19

Or Better

The Official U.S. Standards for Grain provide for an optional grade designation, commonly 

referred to as “or better.” Upon the request of an applicant, flaxseed may be certificated as 

U.S. No. 2 or better, U.S. No. 3 or better, etc. 

For Example:

U.S. No. 2 or better Flaxseed, Dockage 1.0% 

An “or better” grade designation cannot be applied to a U.S. No. 1 grade designation.

Documenting the Grade

Use the following guide for documenting the assigned grade:

• First write the letters “U.S.”,

• Then the abbreviation “No.” and the number of the grade or the words “Sample grade”, 

followed by the words “or better” when applicable.

• The word “flaxseed” shall be shown next, and last the word “dockage” (when applicable) 

and the percentage thereof.

U.S. No. 1 Flaxseed, Dockage 1.0%

U.S. No. 2 or better Flaxseed, Dockage 1.0%
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 1

Chapter 5: Oats

Grain Grading Primer

Chapter 5

Oats
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 2

Contents

Chapter 5: Oats

Definition of Oats ....................................................................................................................4

Grade Requirements ..............................................................................................................5

Special Grades........................................................................................................................5

Heating ....................................................................................................................................6

Distinctly Low Quality ............................................................................................................7

Processing the Original Sample ...........................................................................................7

Boerner Divider.......................................................................................................................8

File Sample..............................................................................................................................9

Use Moisture Proof Containers .............................................................................................9

Odor Determination ..............................................................................................................10

Odors .....................................................................................................................................10

Moisture Determination .......................................................................................................11

General Appearance .............................................................................................................12

Bright Oats ............................................................................................................................12

Slightly Weathered Oats ......................................................................................................13

Materially Weathered Oats ...................................................................................................14

Test Weight ...........................................................................................................................14

TW Procedure .......................................................................................................................15

Heavy/Extra-Heavy Oats ......................................................................................................15

Check for Insects..................................................................................................................15

Live Weevils ..........................................................................................................................16
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 3

Other Live Insects ................................................................................................................16

Sample Grade Factors .........................................................................................................17

Determine Thin Oats ............................................................................................................17

Thin Oats Procedure ............................................................................................................18

Dividing the Work Sample ...................................................................................................19

Determine Smutty Oats ........................................................................................................20

Determine Garlicky Oats ......................................................................................................20

Ergoty Oats ...........................................................................................................................20

Sound Oats ...........................................................................................................................21

Calculating Sound Oats .......................................................................................................21

Foreign Material & Other Grains .........................................................................................22

Coarse FM & Other Grains...................................................................................................22

Fine FM & Fine Other Grains ...............................................................................................22

Heat-Damaged Kernels ........................................................................................................23

Compute Heat-Damaged Kernels........................................................................................23

Heat-Damage Computation Example..................................................................................24

Other Damaged Kernels.......................................................................................................24

Wild Oats...............................................................................................................................27

Seed Sizing (Official Criteria) ..............................................................................................28

Grade Designations..............................................................................................................28

Documenting the Grade .......................................................................................................29
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 4

Definition of Oats

Oats are defined as grain that consists of 50 percent or more of oats and may contain slightly 

or in combination not more than 25 percent of wild oats and other grains for which standards 

have been established under the United States Grain Standards Act.

Normally, a visual appraisal of the sample is sufficient to determine if the sample meets the 

definition of oats. However, if an analysis is necessary, make the determination on a portion 

of 30 grams.

If the sample does not meet the definition of oats, examine it further to determine if it is either 

another grain for which standards have been established or grain that is not standardized. 

No further analysis is necessary on a sample designated as not standardized grain unless a 

specific factor test is requested.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 5

Grade Requirements

There are no classes or subclasses in oats. Oats are divided into four numerical grades and 

U.S. Sample grade. 

OATS

 Grade

Minimum Limits of - Maximum Limits of -

Test weight 

per bushel 

(pounds)

Sound Oats 

(percent)

Heat-Damaged 

kernels 

(percent)

Foreign 

material 

(percent)

Wild oats 

(percent)

U.S. No. 1 36.0 97.0 0.1 2.0 2.0

U.S. No. 2 33.0 94.0 0.3 3.0 3.0

U.S. No. 31 30.0 90.0 1.0 4.0 5.0

U.S. No. 42 27.0 80.0 3.0 5.0 10.0

U.S. Sample Grade

U.S. Sample Grade are oats that: 

(a) Does not meet the requirements for grades U.S. No.1, 2, 3, or 4; or 

(b) Contains 8 or more stones which have an aggregate weight in excess of 0.2 

percent of the sample weight, 2 or more pieces of glass, 3 or more crotalaria seeds 

(Crotalaria spp.), 2 or more castor beans (Ricinus communis L.), 4 or more particles of an 

unknown foreign substance(s) or a commonly recognized harmful or toxic substance(s), 8 or 

more cockleburs (Xanthium spp.) or similar seeds singly or in combination, 10 or more rodent 

pellets, bird droppings, or an equivalent quantity of other animal filth per 1 1/8 to 1 . quarts of 

oats; or 

(c) Have a musty, sour, or commercially objectionable foreign odor (except smut 

or garlic odor) ; or 

(d) Are heating or otherwise of distinctly low quality. 

1

 Oats that are slightly weathered shall be graded not higher than U.S. No. 3. 

2

 Oats that are badly stained or materially weathered shall be graded not higher than 

 U.S. No. 4. 

Special Grades

Special grades are provided to emphasize special qualities or conditions affecting the value 

of the oats and are added to and made a part of the grade designation. Special grades 

do not affect the numerical or sample grade designation. The oats standards include nine 

special grades: bleached oats, bright oats, ergoty oats, extra-heavy oats, garlicky oats, 

heavy oats, infested oats, smutty oats, and thin oats.

Bleached oats are oats that in whole or in part, have been treated with sulfurous acid or any 

other bleaching agent. 
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 6

Bright oats are oats, except bleached oats, that are of good natural color.

Ergoty oats are oats that contain more than 0.10 percent ergot. Ergot is a hard, reddishbrown or black grain like mass of certain parasitic fungi that replaces oat kernels. 

Heavy oats are oats that have a test weight per bushel of 38 pounds or more but less than 

40 pounds.

Extra-heavy oats are oats that have a test weight per bushel of 40 pounds or more.

Garlicky oats are oats that contain 4 or more green garlic bulblets or an equivalent quantity 

of dry or partly dry bulblets in 500 grams of oats.

Infested oats are oats that are infested with live weevils or other insects injurious to stored 

grain.

Smutty oats are oats that have kernels covered with smut spores to give a smutty 

appearance in mass or that contain more than 0.2 percent of smut balls. 

Thin oats are oats that contain more than 20.0 percent of oats and other matter, except 

fine seeds, that pass through a 0.064 x 3/8 oblong-hole sieve but remain on top of a 5/64 

triangular-hole sieve after sieving.

Heating

Oats developing high temperature from excessive respiration due to microbial activity 

(fermenting), insect infestation, or sprouting is considered heating. As heating progresses 

oats will develop a sour or musty odor. 

Care should be taken not to confuse oats that are heating with oats that are warm because 

of storage in bins, railcars, or other containers during hot weather.

Determine heating on evidence obtained at the time of sampling or on the basis of the 

sample as a whole.

Grade heating oats as U.S. Sample Grade and record the word “Heating” in the “Remarks” 

section of the certificate.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 7

Distinctly Low Quality

Consider oats distinctly low quality when they are obviously of inferior quality and the existing 

grade factors or guidelines do not accurately reflect the inferior condition.

Use all available information to determine whether the oats are of distinctly low quality. This 

includes a general examination of the oats during sampling and an analysis of the obtained 

sample.

Oats containing two or more stones, pieces of glass, pieces of concrete, or other pieces 

of wreckage or debris which are visible to the sampler but too large to enter the sampling 

device are considered distinctly low quality.

Oats that are obviously affected by other unusual conditions which adversely affect the 

quality of the oats and cannot be properly graded by use of the grading factors specified or 

defined in the standards are considered distinctly low quality.

Grade distinctly low quality oats U.S. Sample Grade. Record the reason(s) why the oats were 

distinctly low quality on the certificate.

Processing the Original Sample

The first step in grading an oats sample is to use a Boerner divider to reduce the original 

sample into a file sample and a work portion.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 8

Boerner Divider

The Boerner divider reduces the size 

of a grain sample while maintaining its 

representativeness. Each pass of the 

sample through the divider splits the 

sample into two equal portions. The 

Boerner Divider, consists of a hopper, 

inverted cone, and a series of baffles 

directing the grain into two collection 

pans. As the valve or gate at the base 

of the hopper is opened, gravity carries 

the grain over the cone, which serves 

as a surface by which the kernels can 

separate into a single layer. 

Arranged in a circle at the base of the cone are a series of baffles forming alternate channels 

and spaces of equal width. They are arranged in a circle at their summit and are directed 

inward and downward, the channels leading to one spout and the spaces to an opposite 

spout. Each kernel has an equal chance of falling into a channel or a space, resulting in two 

nearly identical portions of the original sample.

• When Operating the Boerner Divider:

• Check the divider for condition and cleanliness.

• Close the hopper valve.

• Place empty collection pans under the discharge spout.

• Pour the sample into the hopper.

• Open the valve quickly.

For larger samples, feed more grain into the hopper during the dividing process.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 9

File Sample

A “file sample,” is a representative sample 

or representative portion of a sample that 

is retained for a specified period of time for 

reference or review purposes.

File samples should be of sufficient size to 

accommodate subsequent examinations or 

analysis. 

The file sample shall be an unworked 

portion (if available) of the representative 

sample used for the inspection. 

The worked portion may be retained as the 

final file only when insufficient sample is 

available for an unworked file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, or similar containers that allow moisture losses. Use 

metal cans, plastic containers, and plastic bags to preserve the sample integrity. 

Do not file samples with paper identification inserted in the grain. Paper absorbs moisture 

and lowers the moisture of the grain.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 10

Odor Determination

Determine odor on evidence obtained at the time 

of sampling or on the ample either before or after 

the removal of foreign material. The inspector is 

responsible for making the final determination for all 

odors but a consensus of experienced inspectors 

should be used, whenever possible, on samples 

containing marginal odors. The consensus approach is 

not required if no odor or a distinct odor is detected. 

Odors are classified as OK, Musty, Sour, or COFO 

(commercially objectionable foreign odors). 

Grade oats containing a “distinct” musty, sour, or 

commercially objectionable foreign odor as U.S. 

Sample grade. Record the words “Musty,” “Sour,” or 

“Commercially Objectionable Foreign Odor” in the 

“Remarks” section of the certificate.

Odors

Musty odors indicate the presence of fungal activity in the grain and are generally 

characterized as an earthy smell. 

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are 

often characterized as an acrid, boot pit or pigpen smell. 

Commercially objectionable foreign odors are odors, except smut and garlic odors, foreign to 

grain that render it unfit for normal commercial usage. 

Fumigant or insecticide odors are considered commercially objectionable foreign odors if 

they linger and do not dissipate. When a sample of oats contains a fumigant or insecticide 

odor that prevents the determination as to whether any other odors exists allow the work 

portion to aerate in an open container for 4 hours, or less, if the odor dissipates in less time. 

Consider the sample as having a commercially objectionable foreign odor if the fumigant or 

insecticide odor persists.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 11

Moisture Determination

Moisture is the water content in grain.

Determine moisture on approximately 400 grams of the original sample. 

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. 

 DICKEY-john GAC2500 Perten AM5200-A

Basically, the instruments measure the change in capacitance of two parallel plates when 

grain is placed between them. As the moisture content within the grain increases or 

decreases so does its contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.

Record the percent of moisture to the nearest tenth percent.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 12

General Appearance

Oats has three general appearance factors. They are “bright” oats, “slightly weathered” oats, 

and “badly stained or materially weathered” oats. The factors “Slightly Weathered,” and 

“Badly Stained or Materially Weathered” denote a discolored condition caused by adverse 

weather conditions. 

Determine general appearance on the sample as a whole. Consider oats “slightly 

weathered,” or “badly stained or materially weathered” when the sample is equal to or worse 

than the oats in the visual reference image. No visual reference image exists for the special 

grade “Bright Oats”. 

Record the words “Bright,” “Slightly Weathered, “or “Badly Stained or Materially Weathered” 

in the “Remarks” section of the certificate.

Bright Oats

Bright oats are oats which have been ripened and harvested under favorable weather 

conditions and have a good natural color. 

Oats which do not have a good natural color usually appear dull and lifeless, or are stained, 

or green from immaturity. Do not consider a mixture of bright oats with any appreciable 

quantity of poorly colored oats as bright, but bright oats which contain smut masses or a light 

trace of smut spores on the kernels are considered bright.

Oats which did not have a good natural color but were treated with a bleaching agent to 

improve their color and appearance are considered “Bleached”.

Determine bleached on the general appearance and odor of the sample as a whole. 

The odor of sulfur or any other bleaching agent is associated with bleached oats. When the 

odor or general appearance indicate that oats have been artificially bleached, either in whole 

or in part, the oats are “bleached.”

When applicable grade bleached oats in accordance with the Special Grades section.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 13

Slightly Weathered Oats

In order for a sample of oats to be designated slightly weathered, each individual kernel 

must have a slightly dusty, gray appearance on the brush end in sufficient amounts to give 

the entire sample a slightly weathered appearance or the sample may contain severely 

weathered kernels in a sufficient number to give it a slightly weathered appearance. In either 

case, the oats are slightly weathered. 

Oats that are slightly weathered shall be graded not higher than U.S. No. 3.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 14

Materially Weathered Oats

When kernel discoloration due to weather has progressed to a point where many of the 

kernels are badly discolored and weathered, the oats are considered “badly stained or 

materially weathered”. 

Oats that are badly stained or materially weathered shall be graded not higher than U.S. No. 4.

Test Weight

Test weight is the weight per Winchester bushel or 2,150.42 cubic inches. Determine test 

weight on a portion of sufficient quantity to overflow the kettle. 

Record test weight results on the work record as displayed on the electronic scale or in 

whole and half pounds. Disregard fractions of a half-pound. Record the test weight on the 

certificate in whole and half pounds. 

If requested, convert the pounds per bushel result to kilograms per hectoliter using the 

formula pounds per bushels times 1.287 equals kilograms per hectoliter and record in the 

“Remarks” section in whole and tenths. 

lbs./bu. X 1.287 = kg/hl.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 15

TW Procedure

Position the hopper over the center of the kettle, making sure the hopper valve is closed. 

Pour grain into the hopper. 

Open the valve allowing the grain to overflow the kettle. Once the hopper is clear of grain 

move the hopper to the side. 

With a rounded edge striker, place it on the edge of the kettle and move the striker in three 

zigzag motions across the kettle leveling the grain. 

Move the kettle to a scale and record the test weight measurement.

Heavy/Extra-Heavy Oats

There are two special grades in oats that are based on test weight. First, extra-heavy oats 

are oats that have a test weight per bushel of 40 pounds or more. And secondly heavy oats 

which are oats that have a test weight per bushel of 38 pounds or more but less than 40 

pounds.

When applicable, make the special grades “Extra Heavy” or “Heavy” a part of the grade 

designation and record on the certificate.

Check for Insects

Check the lot as a whole and/or the sample as a whole for insects. 

The presence of any live weevil or other live insects injurious to stored grain indicates the 

probability of infestation and warns that the oats must be carefully examined to determine 

if they are infested. In such cases, examine the work sample and the file sample before 

reaching a final conclusion. Do not examine the file sample if the work portion is insect-free.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 16

Samples meeting or exceeding any one of these tolerances are infested:

2 live weevils

10 other live insects

1 live weevil + 5 other live insects

Live Weevils

Live weevils include rice weevils, granary weevils, maize weevils, cowpea weevils, and 

lesser grain borers. 

Rice

Weevil

Granary

Weevil

Maize

Weevil

Cowpea

Weevil

Lessor Grain

Borer

Other Live Insects

Other live insects injurious to stored grain shall include grain beetles, grain moths, and 

larvae.

Angoumois

Grain Moth

Indian Meal

Moth

Red Flour

Beetle

Flat Grain

Beetle
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 17

Sample Grade Factors

Determine U.S. Sample grade criteria before the removal of coarse foreign material and 

other grains based on a work portion of 700 - 800 grams. U.S. Sample grade are oats which 

contain:

• 8 or more stones which have an aggregate weight in excess of 0.2 percent of the 

sample weight, 

• 2 or more pieces of glass, 

• 3 or more crotalaria seeds,

• 2 or more castor beans,

• 8 or more cocklebur or similar seeds singly or in combination, 

• 0 or more rodent pellets, bird droppings, or an equivalent quantity of other animal filth 

per 1 to 11⁄4 quarts of oats, 

• 4 or more particles of an unknown foreign substance or a commonly recognized harmful 

or toxic foreign substance. 

Consider identifiable pieces of grain, processed grain products, like soybean meal, sorghum 

grits, corn meal, bulgur, or feed pellets in grain as foreign material. Unidentifiable materials or 

material unrelated to grain shall function as “unknown foreign substance. “

Determine Thin Oats

Determine “thin oats” on a portion of 250 grams of the original sample.

Thin oats are oats that contain more than 20.0 percent of oats and other matter, except fine 

seeds, that pass through a 0.064 by 3/8-inch oblong hole sieve but remain on top of a 5/64 

inch triangular –hole sieve. 

Fine seeds are all matter that passes through a 5/64 inch triangular-hole sieve.When 

applicable, grade the oats “thin”.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 18

Thin Oats Procedure

To separate the thin oats from the sample, 

mount a 0.064 x 3/8 inch oblong hold sieve 

and a bottom pan on the mechanical sieve 

shaker.

• Next, set the stroke counter for 30 strokes.

• Then, place one-third of the sample in the 

center of the sieve and start the machine.

• After the sieve shaker has stopped, remove 

and clean the sieve and empty the bottom 

pan. Return the material lodged in the 

perforations to the oats on top of the sieve.

• Repeat this operation on the remaining 

portions until the entire sample has been 

sieved.

•

• Take the material which passed through 

the 0.064 x 3/8 inch oblong hole sieve and 

sieve it over a 5/64 inch triangular-hole 

sieve, often called the small buckwheat 

sieve, to remove the fine seeds which may 

be present.

• Place the material that passed through the 

0.064 x 3/8 inch oblong hole sieve on the 

upper edge of the small buckwheat sieve.

• Hold the sieve at a 10-to-20-degree angle and work the material down over the sieve with 

a gentle side-to-side motion.

The fine seeds, and other material passing through the small buckwheat sieve, are 

considered fine seeds. The oats and other material that passes through the 0.064 x 3/8 

inch oblong hole sieve, but remain on top of the 5/64 inch triangular hole sieve or small 

buckwheat sieve are thin oats. 
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 19

Dividing the Work Sample

At this point, determinations have been made for heating, odor, moisture, general 

appearance, bleached, test weight, infestation, distinctly low quality, sample grade factors, 

and thin. 

Now divide the work sample into fractional portions for determining smut, garlic, ergot, 

foreign material and other grains, heat damaged kernels, wild oats, other damaged kernels , 

and sound oats.

Work Sample

(700 – 800 grams) 

(Coarse Foreign Material and Other Grains)

1st Cut

2nd Cut

1st Cut

3rd Cut

2nd Cut 2nd Cut 2nd Cut

4th Cut

3rd Cut

4th Cut

5th Cut

6th Cut

5th Cut

6th Cut

Smut

Garlic

Ergot

Thin

Foreign Material and Other Grains 

Heat Damage 

Wild Oats 

Sound Oats

Other Damaged 

Kernels
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 20

Determine Smutty Oats

Determine smutty oats on a portion of 500 grams of the 

original sample. Oats that have kernels covered with 

smut spores to give a smutty appearance in mass or 

that contain more than 0.2 percent of smut balls are 

graded smutty.

When smut spores are in a sufficient quantity to give 

the entire sample a smutty appearance, grade the oats 

smutty. In such cases, there is often a sufficient quantity 

of smut balls, in excess 0.2 percent, which would cause 

the sample to grade smutty. 

Smut balls apply in the determination of the special 

grade “Smutty” but also function as foreign material. 

When applicable, grade the oats “Smutty”.

Determine Garlicky Oats

Determine garlicky oats on a portion of 500 grams of 

the original sample. Oats that contain four or more 

green garlic bulblets or an equivalent quantity of dry or 

partly dry bulblets in 500 grams of oats are garlicky.

Green garlic bulblets are bulblets which have retained 

all of their husks intact. Also dry or partly dry bulblets 

are bulblets which have lost all or part of their husks. 

Consider bulblets with cracked husks as dry.

Note that three dry or partly dry bulblets are equal to 

one green garlic bulblet.When appropriate, record the 

word “Garlicky” on the certificate.

Ergoty Oats

Determine ergoty oats on a portion of 250 grams of the 

original sample. Ergoty oats are oats that contain more 

than 0.10 percent ergot. 

Ergot is a hard, reddish-brown or black grain like mass 

of certain parasitic fungi that replaces oat kernels. 

When appropriate, record the word “Ergoty” on the 

certificate.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 21

Sound Oats

Sound oats are kernels and pieces of oat kernels (except wild oats) that are not badly 

ground- damaged, badly weather-damaged, diseased, frost-damaged, germ-damaged, heatdamaged, insect-bored, mold-damaged, sprout-damaged, or otherwise materially damaged. 

To determine the percentage of sound oats, separate all damaged oats and all matter other 

than cultivated oats from the work portion. 

This involves, first separating the coarse foreign material and whole kernels of corn and 

soybeans from the work sample, then separating the foreign material, other grains, heatdamaged kernels, and wild oats from a work portion of 30 grams, and finally separating the 

other damaged kernels from a work portion of 15 grams.

 Foreign Material Other Grains Heat Other Damage Wild Oats

 Damage

Calculating Sound Oats

The sum of the percentages of foreign material, other grains, heat-damaged kernels, other 

damaged kernels, and wild oats subtracted from 100 percent, equals the percentage of 

sound oats.

Record the percentage of sound oats on the certificate to the nearest tenth percent.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 22

Foreign Material & Other Grains

Foreign Material is all matter other than oats, wild oats, and other grains. Consider oat 

clippings and detached oat hulls and pieces of detached hulls as foreign material. Other 

Grains are Barley, corn, cultivated buckwheat, einkorn, emmer, flaxseed, guar, hull-less 

barley, non-grain sorghum, Polish wheat, popcorn, Poulard wheat, rice, rye, safflower, 

sorghum, soybeans, spelt, sunflower seed, sweet corn, triticale, and wheat.

Foreign material and other grains consist of coarse foreign material, coarse other grains, 

fine foreign material, and fine other grains. Record the percent of foreign material (includes 

coarse and fine) on the certificate to the nearest tenth percent. Record the percent of other 

grains (includes coarse and fine) on the work record to the nearest tenth percent.

Coarse FM & Other Grains

For coarse foreign material and coarse other grains, handpick the 700 – 800 gram work 

portion for coarse foreign material and coarse other grains. 

Coarse Foreign Material includes cockleburs, sticks if they are approximately 2.5 cm or more 

in length and 1.3 cm or more in thickness, soybean pods (one-half pod or more), or other 

coarse foreign material which may include large feed pellets, pieces of dirt, sweet corn, and 

edible beans.

Coarse Other Grains, includes whole kernels of corn which are kernels with one-fourth or 

less of the kernel removed and also, whole soybeans which are soybeans with one-fourth or 

less of the soybean removed. Maintain individual separations for coarse foreign material and 

for coarse other grains.

Fine FM & Fine Other Grains

Determine fine foreign material and fine other grains after the removal of coarse foreign 

material and coarse other grains on a work portion of 30 grams. Either handpick the 30-

gram portion for fine foreign material and fine other grains; or use, as an aid, a 5/64-inch 

triangular-hole sieve to remove the fine foreign material and fine other grains.

When using the sieve, gently slide the sample across the sieve then separate the oats, wild 

oats, and fine other grains from the material that passed through the sieve. Remove all fine 

foreign material from the material remaining on top of the sieve.

 Coarse FM Coarse Other Grains Fine FM Fine Other Grains
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 23

Fine Foreign Material includes star thistles, star burs, sandburs, morning glory, kinghead 

seeds, sticks not meeting the criteria for coarse foreign material, soybean pods that are less 

than one-half the total pod, and any other material too small to function as coarse foreign 

material and other grains.

Fine Other Grains includes Broken kernels of corn and sweet corn with more than one-fourth 

of the kernel removed, broken soybeans with more than one-fourth of the soybean removed, 

Dehulled sunflower seeds, and other grains. 

Fine Other Grains include broken kernels of corn with more than one-fourth of the kernel 

removed, broken soybeans with more than one-fourth of the soybean removed, and other 

grains as defined earlier.

Heat-Damaged Kernels

Heat-damaged kernels are Kernels and pieces of oat kernels, other grains, and wild oats 

that are materially discolored and damaged by heat. Determine heat-damaged whole corn 

and soybeans on a work portion of 700 - 800 grams. Whole corn and soybeans that show 

evidence of distinct discoloration and damage by heat are examined to determine if they are 

heat damaged. 

Determine heat-damaged Oats, Wild Oats, and Other Grains after the removal of coarse 

foreign material and coarse other grains on a work portion of 30 grams. Kernels of oats 

and wild oats that show evidence of distinct discoloration and damage by heat are hulled to 

determine if they are heat damaged. When the hulled kernels show a reddish discoloration 

extending out of the germ, the kernels are heat damaged. 

Groats showing moldy, mold-like substance, sprouted, or dead germs but no reddish cast or 

discoloration function against sound cultivated oats but not as heat-damaged kernels. Other 

grains that show evidence of distinct discoloration and damage by heat are examined to 

determine if they are heat-damaged.

Compute Heat-Damaged Kernels

Compute the percentage of heat-damaged kernels by adding the percentage of heatdamaged whole corn and soybeans to the percentage of heat-damaged oats, wild oats, and 

other grains in hundredths (disregard thousandths).

Record the percent of heat-damaged kernels to the nearest tenth percent on the certificate.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 24

Heat-Damage Computation Example

Weight of representative sample = 700 grams

Weight of heat-damaged whole corn 

& soybeans = 3.00 grams

Percent of heat-damaged whole corn 

& soybeans = (3.00 ÷ 700) x 100 = 0.42 %

Weight of representative portion = 30.00 grams

Weight of heat-damaged oats, wild oats, 

& other grains = 0.30 gram

Percent of heat-damaged oats, wild oats, 

& other grains = (0.30 ÷ 30.00) x 100 = 1.00 %

Percent of heat-damaged kernels = (0.42 + 1.00) = 1.42 % = 1.4 %

Other Damaged Kernels

Determine other damaged kernels after the removal of coarse foreign material and coarse 

other grains on a work portion of 30 grams. In general, oat kernels are considered damaged 

for inspection and grading purposes only when the damage is distinctly apparent and of such 

character as to be recognized as damaged for commercial purposes. 

Other damaged kernels include kernels and pieces of oat kernels, except heat-damaged 

kernels, that are badly ground-damaged, badly weather-damaged, diseased, frost-damaged, 

germ-damaged, insect-bored, mold-damaged, sprout-damaged, or otherwise materially 

damaged. 

Heat-damaged kernels are not considered as part of other damaged kernels. Oat groats; 

hull-less oats; and green, immature kernels of oats that are not otherwise damaged are 

considered sound. 

Record the percent of other damaged kernels to the nearest tenth percent.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 25

Badly Ground / Weather Damage

Kernels which are badly discolored by ground and/or weather condition. 

The discoloration must appear on both sides of the kernel equal to or greater than shown to 

be considered damage.

Such damaged kernels do not count as “sound cultivated oats”.

Weather Damaged (Stained)

A B 

Processing discolored (stained) oats reduce rolled oat yields and may result in a less than 

desirable flake color, depending on its severity. 

Oat groats having a dark brown/black discoloration on the surface meeting the minimum 

coverage and intensity as shown are considered damaged.

Kernel A is a Suspect Oat. Its lightly discolored hull indicates possible damage. The hull 

must be removed to confirm the presence and extent of discoloration.

The hull has been removed from Kernel B and the damage is confirmed. This kernel 

illustrates the minimum coverage and intensity required.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 26

Germ Damage (Sick / mold)

Kernels in which the germ is discolored or moldy as a result of microbial activity are 

damaged.

Kernels and pieces of oats that have discolored germs as dark or darker than Kernel A shall 

be damaged. Discolored germs that do not meet the minimum coverage requirement may 

be considered damage provided the degree of discoloration is greater than shown and the 

overall “prorated” appearance meets the minimum coverage and intensity level depicted.

Kernels containing any amount of mold such as Kernel B shall be damage. The hull must be 

removed to determine extent of damage to germ. 

Such damaged kernels do not count as “sound cultivated oats”.

Mold Damage

A B 

Kernels in which mold has penetrated the hull leaving a grayish discoloration on the groat to 

the minimum coverage and intensity as shown are considered damaged.

The hull must be removed to determine extent of damage. 

Such damaged kernels do not count as “sound cultivated oats”.

Insect Damage

Kernels which have been bored or tunneled by insects are considered damaged. 

Such damaged kernels do not count as “sound cultivated oats”.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 27

Sprout Damage

Kernels which have sprouted or generally have a crack in the seed coat over the germ area.

The hull must be removed to determine if cracked seed coat indicates sprouting. 

Such damaged kernels do not count as “sound cultivated oats”.

Wild Oats

Determine wild oats after the removal of coarse foreign material and coarse other grains on a 

work portion of 30 grams. 

Wild oats are usually identified by their characteristic slender kernels with twisted awns and 

basal hairs or bristles on the germ end of the kernels. 

Wild oats function against sound oats.
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 28

Seed Sizing (Official Criteria)

Seed Sizing is considered an “official criteria” 

and is determined only upon request. It does 

not affect the grade designation. Determine 

seed size on a portion of 250 grams of the 

original sample.

Use a 5/64 x 3/4 inch slotted hole sieve to 

determine the percentage of oats and other 

materials, except for fine seeds, that pass 

through the sieve.

Take the material which passed through the 5/64x 3/4 inch slotted hole sieve and sieve it 

over a 5/64 triangular-hole or small buckwheat sieve. The fine seeds and other material 

passing through the 5/64 triangular-hole sieve or small buckwheat sieve are considered “fine 

seeds.”

Record the results of the sizing test to the nearest tenth percent in the “Remarks” section of 

the certificate.

Grade Designations

After completing the analysis, assign a grade by comparing the results with the limits for 

each grade factor specified in the grade chart. The factor with the lowest grade designation 

determines the grade assigned to the sample. 
Grain Grading Primer Chapter 5: Oats

October 2016

Page 5 - 29

The Official U.S. Standards for Grain provide for an optional grade designation, 

commonly referred to as “or better.” 

Upon the request of an applicant, oats may be certificated as U.S. No. 2 or better, U.S. No. 

3 or better, etc. An “or better” grade designation cannot be applied to a U.S. No. 1 grade 

designation. 

For example, U.S. No. 2 or better oats.

Documenting the Grade

Use the following guidelines when documenting grades on work records and certificates.

• First write the letters “U.S.”, then the abbreviation “No.” and the number of the grade or the 

words “Sample Grade”,

• Next the words “or better” when applicable, and the special grade, (For Example “Heavy“) 

when applicable,

• Followed by the word “oats”, and the applicable special grade (For Example “Ergoty) in 

alphabetical order.

Example: U.S. No. 1 Heavy Oats, Ergoty
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 1

Chapter 6: Rye

Grain Grading Primer

Chapter 6

Rye
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 2

Contents

Chapter 6: Rye

Rye Definition .........................................................................................................................4

Grade Requirements ..............................................................................................................5

Special Grades........................................................................................................................5

Heating ....................................................................................................................................6

Distinctly Low Quality ............................................................................................................6

Processing the Original Sample ...........................................................................................7

Boerner Divider.......................................................................................................................8

File Sample..............................................................................................................................9

Use Moisture Proof Containers .............................................................................................9

Check Odor ...........................................................................................................................10

Check for Insects..................................................................................................................10

Live Weevils .......................................................................................................................... 11

Other Live Insects ................................................................................................................ 11

Garlicky and Light Garlicky .................................................................................................12

Check for Sample Grade Factors ........................................................................................13
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 3

Determine Moisture ..............................................................................................................14

Dockage.................................................................................................................................14

Dockage Procedure ..............................................................................................................15

Recording Dockage ..............................................................................................................16

Rye Containing Wild Buckwheat .........................................................................................16

Rye Containing Canola-Flaxseed........................................................................................17

Check for Stones ..................................................................................................................17

Test Weight ...........................................................................................................................18

Processing the Work Sample ..............................................................................................19

Thin and Plump Rye .............................................................................................................20

Smutty and Light Smutty Rye .............................................................................................21

Ergoty Rye.............................................................................................................................21

Foreign Material ....................................................................................................................22

Damaged Kernels .................................................................................................................22

Grade Designation................................................................................................................25

Documenting the Grade .......................................................................................................26
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 4

Rye Definition

Rye is defined as grain that, before the removal of dockage, consists of 50 percent or more 

of common rye and not more than 10 percent of other grains for which standards have been 

established under the United States Grain Standards Act and that, after the removal of 

dockage, contains 50 percent or more of whole kernels of rye.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 5

Grade Requirements

There are no classes or subclasses in rye. Rye is divided into four numerical grades and 

U.S. Sample grade. The factors affecting rye grades include: test weight, foreign material, 

heat damaged kernels, total damage, and thin.

RYE

Grade

Minimum Limits of - Maximum Limits of -

Test weight

per bushel

(pounds)

Foreign Material Damaged Kernels

Thin Rye

(percent)

Foreign 

matter

other than 

wheat 

(percent) 

Total 

(percent)

(percent) 

Heat 

Damaged 

(percent)

Total 

(percent)

U.S. No. 1 56.0 1.0 3.0 0.2 2.0 10.0

U.S. No. 2 54.0 2.0 6.0 0.2 4.0 15.0

U.S. No. 3 52.0 4.0 10.0 0.5 7.0 25.0

U.S. No. 4 49.0 6.0 10.0 3.0 15.0 - - -

U.S. Sample grade is rye that:

• Does not meet the requirements for the grades U.S. Nos. 1, 2, 3, or 4; or

• Contains stones, glass, crotalaria seeds, castor beans, particles of an unknown foreign 

substance or a commonly recognized harmful or toxic foreign substance, rodent pellets, 

bird droppings, or an equivalent quantity of other animal filth; or

• Has a musty, sour, or commercially objectionable foreign odor (except smut or garlic 

odor); or

• Is heating or otherwise of distinctly low quality.

Special Grades

Special Grades draw attention to unusual conditions in grain, and are made part of the grade 

designation. The special grades in Rye are: Ergoty, Garlicky, Infested, Light Garlicky, Light 

Smutty, Plump, and Smutty.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 6

Heating

Rye developing high temperature from excessive respiration due to microbial activity 

(fermenting), insect infestation, or sprouting is considered heating. Heating rye, in its final 

stages, will usually have a sour or musty odor. 

Care should be taken not to confuse rye that is heating with rye that is warm because of 

storage in bins, railcars, or other containers during hot weather.

Determine heating on evidence obtained at the time of sampling or on the basis of the 

sample as a whole.

Grade heating rye as U.S. Sample Grade and record the word “Heating” in the “Remarks” 

section of the certificate.

Distinctly Low Quality

Consider rye distinctly low quality when it is obviously of inferior quality and the existing 

grade factors or guidelines do not properly reflect the inferior condition. 

Use all available information to determine distinctly low quality. This includes a general 

examination of the rye during sampling and an analysis of the obtained sample.

Rye containing two or more stones, pieces of glass, pieces of concrete, or other pieces of 

wreckage or debris which are visible to the sampler and too large to enter the sampling 

device is considered distinctly low quality.

Rye that is obviously affected by other unusual conditions which adversely affect the quality 

of the rye and cannot be properly graded by use of the grading factors specified or defined in 

the standards is considered distinctly low quality.

Grade distinctly low quality rye as U.S. Sample Grade. Record the words “Distinctly Low 

Quality” and the reason why in the “Remarks” section of the certificate.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 7

Processing the Original Sample

The first step in grading a rye seed sample is to use a Boerner divider to reduce the original 

sample into:

• A file sample of approximately 1350 grams.

• A work portion of approximately 1000 grams.

 FILE WORK
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 8

Boerner Divider

The Boerner divider reduces the size of a grain sample while maintaining its 

representativeness. Each pass of the sample through the divider splits the sample into two 

equal portions. The Boerner Divider, consists of a hopper, inverted cone, and a series of 

baffles directing the grain into two collection pans. As the valve or gate at the base of the 

hopper is opened, gravity carries the grain over the cone, which serves as a surface by which 

the kernels can separate into a single layer. 

Arranged in a circle at the base of the cone are a series of baffles forming alternate channels 

and spaces of equal width. They are arranged in a circle at their summit and are directed 

inward and downward, the channels leading to one spout and the spaces to an opposite 

spout. Each kernel has an equal chance of falling into a channel or a space, resulting in two 

nearly identical portions of the original sample.

When Operating the Boerner Divider:

Check the divider for condition and cleanliness.

Close the hopper valve.

Place empty collection pans under the discharge spout.

Pour the sample into the hopper.

Open the valve quickly.

For larger samples, feed more grain into the hopper during the dividing process.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 9

File Sample

A “file sample,” is a representative sample or 

representative portion of a sample that is retained 

for a specified period of time for reference or review 

purposes.

File samples should be of sufficient size to 

accommodate subsequent examinations or analysis. 

The file sample shall be an unworked portion (if 

available) of the representative sample used for the 

inspection. 

The worked portion may be retained as the final file only 

when insufficient sample is available for an unworked 

file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, or similar containers that allow moisture losses.

Use metal cans, plastic containers, 

and plastic bags to preserve the 

sample integrity.

Do not file samples with paper 

identification inserted in the grain.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 10

Check Odor

Determine odor on evidence obtained at 

the time of sampling or on the sample either 

before or after the removal of dockage. Odors 

are classified as OK, Musty, Sour, or COFO 

(commercially objectionable foreign odors). 

The inspector is responsible for making the 

final determination for all odors. A consensus 

of experienced inspectors is used, whenever 

possible, on samples containing marginal odors. 

The consensus approach is not required if no 

odor or a distinct odor is detected.

Grade rye containing a “distinct” musty, sour, 

or commercially objectionable foreign odor as 

U.S. Sample grade. Record the words “Musty,” 

“Sour,” or “Commercially Objectionable Foreign 

Odor” in the “Remarks” section of the certificate.

Musty odors indicate the presence of fungal activity in the grain and are generally 

characterized as an earthy smell. 

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are 

often characterized as an acrid, boot pit or pigpen smell. 

Commercially Objectionable Foreign Odors. Commercially objectionable foreign odors 

are odors, except smut and garlic odors, foreign to grain that render it unfit for normal 

commercial usage.

Fumigant or insecticide odors are considered commercially objectionable foreign odors if 

they linger and do not dissipate.

Check for Insects

Determine infestation on the lot as a whole and/or the sample as a whole. Infested rye is rye 

that is infested with live weevils or other live insects injurious to stored grain.

The presence of any live weevil or other live insects injurious to stored grain indicates the 

probability of infestation and warns that the rye must be carefully examined to determine if 

it is infested. In such cases, examine the work sample and file sample before reaching a 

conclusion as to whether or not the rye is infested. Do not examine the file sample if the 

work portion is insect free. 
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 11

Samples meeting or exceeding any one of these tolerances are infested:

2 live weevils

2 other live insects

1 live weevil + 1 other live insect

When applicable, include the word “Infested” in the grade designation.

Live Weevils

Live weevils include rice weevils, granary weevils, maize weevils, cowpea weevils, and 

lesser grain borers. 

Rice

Weevil

Granary

Weevil

Maize

Weevil

Cowpea

Weevil

Lessor Grain

Borer

Other Live Insects

Other live insects injurious to stored grain shall include grain beetles, grain moths, and 

larvae.

Angoumois

Grain Moth

Indian Meal

Moth

Red 

Flour

Beetle

Flat 

Grain

Beetle
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 12

Garlicky and Light Garlicky

Determine garlicky and light garlicky 

before the removal of dockage on a 

potion of 1,000 grams. Rye is Garlicky 

if it contains in a 1,000 gram portion 

more than six green garlic bulblets or an 

equivalent quantity of dry or partly dry 

bulblets.

Rye is Light Garlicky if it contains in a 

1,000 gram portion, two or more, but not 

more than six, green garlic bulblets or an 

equivalent quantity of dry or partly dry 

bulblets. 

Green garlic bulblets are bulblets which 

have retained all of their husks intact. Dry 

or partly dry garlic bulblets are bulblets 

which have lost all or part of their husks. 

Consider bulblets with cracked husks as 

dry. Three dry or partly dry garlic bulblets 

are equal to one green bulblet.

When applicable, include the words “Garlicky” or “Light Garlicky” in the grade designation. 

Upon request, record the number of garlic bulblets in whole and thirds.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 13

Check for Sample Grade Factors

Determine U.S. Sample grade criteria, except for stones, before the removal of dockage 

based on a work portion of 1,000 - 1,050 grams. Rye is Sample Grade if it contains:

Consider identifiable pieces of grain, processed grain products such as soybean meal, 

sorghum grits, corn meal, or bulgur, or feed pellets in grain as foreign material. Unidentifiable 

materials or material unrelated to grain shall function as “unknown foreign substance.”

2 or more

Animal Filth

2 or more

Glass

2 or more

Castor Beans

3 or more

Crotalaria Seeds

4 or more

Unknown Foreign 

Substance

Grade rye U.S. Sample grade when one or more of the limits above are exceeded. Record 

the reasons why in the “Remarks” section of the certificate. Record count factors to the 

nearest whole number.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 14

Determine Moisture

Moisture is the water content determined before the removal of dockage on approximately 

650 grams.

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. 

 DICKEY-john GAC2500 Perten AM5200-A

Basically, the instruments measure the change in capacitance of two parallel plates when 

grain is placed between them. As the moisture content within the grain increases or 

decreases so does its contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.

Certify moisture to the nearest tenth percent.

Dockage

Determine dockage on a portion of 1,000 - 1,050 grams of the original sample. 

Dockage is all matter other than rye that can be removed from the original sample by use of 

an approved device in accordance with procedures prescribed in FGIS instructions. 

Also, underdeveloped, shriveled, and small pieces of rye kernels removed in properly 

separating the material other than rye and that cannot be recovered by properly rescreening 

and re-cleaning.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 15

Dockage Procedure

When determining 

dockage on rye, the 

first step is to set air 

control on 4 and the 

feed control to 6. 

Second, insert the No. 

25 plastic riddle in the 

riddle carriage. 

Use no sieve in the top 

sieve carriage. 

Next insert the No. 2 

sieve in the middle and 

bottom sieve carriages. 

Then start the Carter 

Dockage Tester and 

pour sample into feed 

hopper.

• The aspirated 

material in the air 

collection pan is 

dockage. 

1,000 - 1,050 

gram sample

Air #4

Hopper

Feed #6

#2 Middle

Sieve

#2 Bottom

Sieve

Air Collection Pan

# 25 DKG #1

Riddle

Over Riddle

DKG #2

Return threshed and 

sprouted kernels to 

cleaned rye

Cleaned Rye

OverBottom 

Sieve

If less than

50% rye 

DKG #3

Bottom Collection Pan

DKG #4

Total DKG = DKG 1+2+3+4

• Material over the riddle, except for threshed and sprouted kernels, is dockage. 

• Threshed and sprouted kernels of rye that pass over the riddle are not considered 

dockage. Return them to the dockage-free sample. Threshed kernels of rye are kernels 

with either no glumes attached or not more than one glume attached. 

• Consider unthreshed kernels of rye that pass over the riddle as dockage. Unthreshed 

kernels are kernels with glumes attached.

• Material that passed through the bottom sieve is dockage. 

• Material passing over the bottom sieve is dockage if it contains less than 50 percent 

by weight of rye. When the material consists of more than 50 percent by weight of rye, 

return it to the cleaned rye.

• When performing the dockage determination, check the material that passes over the 

riddle for threshed and sprouted kernels of rye.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 16

Recording Dockage

When the sample contains 1 percent or more dockage, record the percentage of dockage on 

the certificate in whole percent with fractions of a percent disregarded.

For example:

1.00 to 1.99 percent is expressed as 1.0 percent

2.00 to 2.99 percent is expressed as 2.0 percent, etc.

To save time, many inspectors check the dockage for garlic bulblets, infestation, and U.S. 

Sample grade factors; except stones.

Rye Containing Wild Buckwheat

If it appears that the sample contains more 

than 0.5 percent of wild buckwheat or similar 

seeds, analyze a portion of approximately 

50 grams of the original sample before the 

removal of dockage. If the portion contains 

more than 0.5 percent of wild buckwheat or 

other similar sized seeds, proceed as follows. 

First, set up the Carter dockage tester by 

setting the air control at 4; setting the feed 

control at 6; inserting a number 25 riddle in the 

riddle carriage, using no sieve in the top sieve 

carriage; inserting a Number 6 sieve in the 

middle sieve carriage, and inserting a number 

2 sieve in the bottom sieve carriage.

When the sample has been run, place approximately 50 grams of the material that passed 

over the Number 2 sieve on the upper edge of a 5/64, or 1.984 millimeter equilateral 

triangular hand sieve. Hold the sieve at a 10 to 20 degree angle and work the material down 

over the sieve with a gentle side to side motion.

Repeat the previous step on additional 50 gram portions until all material that passed over 

the Number 2 sieve has been sieved.

If the material remaining on top of the sieve consists of 50 percent or more of whole or 

broken kernels of rye, return it to the sieved sample. Otherwise, add it to the dockage.

Examine the material that passed through the sieve. If the material consists of 50 percent 

or more by weight of whole or broken kernels of rye, repeat the sieving process on 50 gram 

portions of all the material that passed through the sieve. Do not perform this hand sieving 

process more than twice.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 17

Rye Containing Canola-Flaxseed

There are occasional samples that will 

contain canola or flaxseed after the 

dockage is removed. In such cases, 

separate the canola or flaxseed from the 

cleaned rye. 

If it appears that the sample contains 

0.1 percent or more of canola/flaxseed, 

analyze a dockage-free portion of 50 

grams. If the representative portion 

contains 0.3 percent or more of canola/

flaxseed, sieve the entire dockage-free 

sample with either a 3/64 x 3/8 hand sieve 

or a 0.064 x 3/8 hand sieve, depending on 

which sieve is more appropriate in relation 

to the size of the rye and canola/flaxseed 

kernels in the sample.

To remove the canola/flaxseed, use the following procedure:

• Mount the sieve and a bottom pan on an approved mechanical sieve shaker.

• Place one fourth of the dockage free portion on the sieve.

• Set the stroke counter at 30 strokes.

• When the shaker has stopped, return the material lodged in the perforations to the rye 

remaining on top of the sieve.

• Clean the sieve and repeat this procedure with the three remaining similar sized 

portions.

Check for Stones

Determine stones on the dockage-free portion. Grade the sample “Sample Grade” if it 

contains 8 or more stones or any number of stones in excess of 0.2% by weight.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 18

Test Weight

Test weight is the weight per Winchester 

bushel, 2,150.42 cubic inches.Determine 

test weight on a dockage-free portion of 

sufficient quantity to overflow the kettle.

Position the hopper over the center of the 

kettle, making sure the hopper valve is 

closed. Pour grain into the hopper. 

Open the valve allowing the grain to 

overflow the kettle. Once the hopper is 

clear of grain move the hopper to the side. 

With a rounded edge striker, place it on 

the edge of the kettle and move the striker 

in three zigzag motions across the kettle 

leveling the grain. 

Move the kettle to a scale and record the 

test weight measurement.

Record the test weight on the certificate in whole and tenth pounds to the nearest tenth 

pound. If requested, convert the pounds per bushel result to kilograms per hectoliter using 

the following formula: pounds divided by bushels times 1.287 = kg/hl and record in the 

“Remarks” section in whole and tenths.

lbs/bu X 1.287 = kg/hl
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 19

Processing the Work Sample

At this point, determinations have been made for odor, test weight, moisture, dockage, 

infestation, and sample grade factors. Now divide the dockage-free work sample into 

fractional portions for determination of thin, plump, smut, ergot, foreign material, heat 

damage, and damaged kernels total.

Work Sample 

1,000 – 1,050 grams 

(DKG-Free)

1st Cut

2nd Cut

1st Cut

3rd Cut

2nd Cut 2nd Cut 2nd Cut

3rd Cut

4th Cut

5th Cut

4th Cut

6th Cut

5th Cut

6th Cut

Ergot

Smut

Thin

Plump

Foreign Material

Heat Damage

Damaged Kernels 

(Total)
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October 2016

Page 6 - 20

Thin and Plump Rye

Thin rye is rye and other matter that passes through a 0.064 x 3/8 oblong hole sieve.

Plump rye is rye that contains not more than 5.0 percent of rye and other matter that passes 

through a 0.064 X 3/8 oblong-hold sieve.

Determine thin and plump on a dockagefree portion of 250 grams using the 

following procedure.

• Mount a 0.064 x 3/8 inch oblong 

hole sieve and a bottom pan on the 

mechanical sieve shaker. Set the 

stroke counter for 30 strokes. When 

the shaker has stopped, return the 

material lodged in the perforations to 

the rye remaining on top of the sieve. 

• Consider all material passing through 

the sieve as thin rye. Consider all 

material remaining on top of the sieve 

as plump rye. Return the material 

lodged in the perforations to the rye on 

top of the sieve.

When applicable, record the percentage of thin rye on the certificate to the nearest tenth 

percent. When applicable, plump becomes a part of the grade designation and is included in 

the grade designation.

For example: U.S. No. 1 Plump rye.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 21

Smutty and Light Smutty Rye

Smut is a plant disease characterized 

by the appearance of smut balls or smut 

spores.

Determine “Smutty” on a dockage-free 

portion of 250 grams. Smutty Rye is rye that 

contains in a 250-gram portion smut balls, 

portions of smut balls, or spores of smut in 

excess of a quantity equal to 30 smut balls 

of average size.

Determine “Light smutty” on the sample as 

a whole or on a dockage free portion of 250 

grams. 

Light Smutty Rye is Rye that has an 

unmistakable odor of smut, or that contains 

in a 250-gram portion smut balls, portions 

of smut balls, or spores of smut in excess of 

a quantity equal to 14 smut balls but not in 

excess of a quantity equal to 30 smut balls 

of average size. 

Smut balls also function as foreign matter 

other than wheat. When applicable, record 

the words “Smutty,” or “Light smutty” on the 

certificate.

Ergoty Rye

Determine ergoty on a dockage-free portion 

of 250 grams. Ergot is a hard, reddishbrown or black grain-like mass of certain 

parasitic fungi that replaces the kernel of 

rye. Ergoty rye is rye that contains more 

than 0.30 percent of ergot. 

Ergot applies in the determination of ergoty 

but also functions as foreign matter other 

than wheat.

When applicable, record the word “Ergoty” 

on the certificate.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 22

Foreign Material

Determine foreign material on a dockage-free 

portion of 50 grams.

Foreign material is all matter other than rye 

that remains in the sample after the removal 

of dockage. In rye, the factor foreign material 

is divided into foreign matter other than wheat 

and foreign material.

Remove all matter other than rye from the 

representative portion and determine the 

percentage of foreign material.

Remove the wheat from the total foreign 

material separation. The percentage of foreign 

matter other than wheat is then based on the 

remaining foreign material after the removal of 

the wheat.

Record the percentages of foreign matter other than wheat and foreign material (total) on the 

certificate to the nearest tenth percent.

Damaged Kernels

Determine damaged kernels on a dockagefree portion of 15 grams. 

In general, kernels of rye and other grains 

are considered damaged for inspection and 

grading purposes only when the damage is 

distinctly apparent and of such character as 

to be recognized as damaged for commercial 

purposes. 

Damaged kernels includes kernels, pieces of 

rye kernels, and other grains that are badly 

ground damaged, badly weather damaged, 

diseased, frost damaged, germ damaged, 

heat damaged, insect bored, mold damaged, 

sprout damaged, or otherwise materially 

damaged.

Record the percent of damaged kernels to the nearest tenth percent on the certificate.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 23

Germ-Damaged Kernels

Kernels in which the germ is discolored or moldy as a result of microbial activity are 

damaged. 

The bran coat should be removed carefully because scraping too deeply could remove the 

damage.

Sprout-Damaged Kernels

Kernels that have the germ end broken open from germination and show a sprout and 

kernels that have sprouted but which have the sprouts broken off are damaged.

Exposed Germs Not Damaged

At times, rye can present a ragged appearance, particularly after excessive handling. In 

many cases, the germ ends are slightly rubbed off, giving these kernels the appearance of 

having been sprouted. Close examination, however, usually indicates that the kernels have 

not sprouted but that the ends have merely been rubbed off through excessive handling. 

Such kernels, unless otherwise damaged, are considered sound.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 24

Insect Chewed & Sprout Sockets

 A B

Do not confuse insect-chewed germs with sprout sockets. Kernels from which the germs 

have been chewed are considered sound kernels unless otherwise damaged (kernel A). 

However, “sprout sockets” which are kernels from which the sprouts have broken off are 

considered damaged (kernel AB).

Insect-Bored Kernels 

Kernels which have been bored or tunneled by insects are damaged.

Other Damaged Kernels

Kernels which have cracks, breaks, are chewed, contain mold or fungus, or are diseased are 

also damaged.

Heat-Damaged Kernels

Determine heat-damaged kernels on a dockage-free 

portion of 30 grams. Heat-damaged kernels are kernels, 

pieces of rye kernels, and other grains that are materially 

discolored and damaged by heat. In most cases, it is 

necessary to cross-section the kernels to determine if 

they are heat-damaged. Heat-damaged kernels are 

kernels which are reddish-brown, mahogany, or creamy 

in cross-section.

Record the percent of heat-damaged kernels to the nearest tenth percent on the certificate.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 25

Grade Designation

After completing the analysis, assign a grade by comparing the results with the limits for 

each grade factor specified in the grade chart. The factor with the lowest grade designation 

determines the grade assigned to the sample. 

The Official U.S. Standards for Grain provide for an optional grade designation, commonly 

referred to as “or better.” Upon the request of an applicant, rye may be certified as U.S. No. 

2 or better, U.S. No. 3 or better, etc. An “or better” grade designation cannot be applied to a 

U.S. No. 1 grade designation.
Grain Grading Primer Chapter 6: Rye

October 2016

Page 6 - 26

Documenting the Grade

Use the following guidelines when documenting grades on work records and certificates.

• First write the letters “U.S.”, then the abbreviation “No.” and the number of the grade or 

the words “Sample Grade”, 

• Next the words “or better” when applicable, and the special grade “Plump” when 

applicable,

• Followed by the word “rye”, the applicable special grade in alphabetical order, and lastly 

the word “dockage” (when applicable) and the percentage thereof.

Example: U.S. No. 1 Plump rye, Ergoty, Dockage 2.0%
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Chapter 7: Sorghum

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Chapter 7: Sorghum

Grain Grading Primer

Chapter 7

Sorghum
Contents

Chapter 7: Sorghum

Sorghum Definition ........................................................................................................................4

Classes............................................................................................................................................5

Grades and Grade Requirements ................................................................................................. 6

U.S. Sample Grade .........................................................................................................................6

Heating ............................................................................................................................................7

Distinctly Low Quality ....................................................................................................................7

General Appearance .......................................................................................................................8

Special Grades................................................................................................................................9

Processing the Original Sample ................................................................................................... 9

Boerner Divider.............................................................................................................................10

File Sample.................................................................................................................................... 11

Determine Moisture ......................................................................................................................12

Dockage.........................................................................................................................................13

Test Weight per Bushel ................................................................................................................15

TW Procedure ...............................................................................................................................16
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Processing the Work Sample ..............................................................................................17

Foreign Material ....................................................................................................................18

Broken Kernels ....................................................................................................................18

Broken Kernels and Foreign Material ................................................................................19

Computing BNFM .................................................................................................................20

BNFM Example .....................................................................................................................20

Unattached Hulls ..................................................................................................................21

Non-grain Sorghum ..............................................................................................................21

Damaged Kernels .................................................................................................................22

Visual Reference Images .....................................................................................................22

Bleach Procedure ................................................................................................................25

Computing Damaged Kernels .............................................................................................26

Heat Damage .......................................................................................................................27

Determining Class ...............................................................................................................27

Tannin Sorghum (Bleached) ...............................................................................................28

Other Official Criteria ...........................................................................................................28

Determine Grade Designation .............................................................................................29
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Chapter 7: Sorghum

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Sorghum Definition

Sorghum is defined as grain that, before the removal of dockage, consists of 50 percent or 

more of whole kernels of sorghum, excluding nongrain sorghum, and not more than 10.0 

percent of other grains for which standards have been established under the United States 

Grain Standards Act.

Normally, a visual appraisal of the sample is sufficient to determine if it meets the definition of 

sorghum. However, if an analysis is necessary, make the determination before the removal 

of dockage on a portion of 30 grams.
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Chapter 7: Sorghum

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Classes

Sorghum is divided into four classes: Sorghum, Tannin sorghum, White sorghum, and Mixed 

sorghum. There are no subclasses in sorghum.

The class Sorghum is sorghum which is low in tannin 

content due to the absence of a pigmented testa or 

subcoat and contains less than 98.0 percent White 

sorghum and not more than 3.0 percent Tannin 

sorghum. The pericarp color of this class may appear 

white, yellow, pink, orange, red, or bronze. The 

pericarp is the outer layers of the sorghum grain and is 

fused to the seedcoat.

The class Tannin Sorghum is sorghum which is high 

in tannin content due to the presence of a pigmented 

testa or subcoat and contains not more than 10.0 

percent non-Tannin sorghum. The pericarp color of 

this class is usually brown, but may also be white, 

yellow, pink, orange, red, or bronze.

The class White Sorghum is sorghum which is low in 

tannin content due to the absence of a pigmented testa 

or subcoat and contains not more than 2.0 percent 

sorghum of other classes. The pericarp color of this 

class is white or translucent and includes sorghum 

containing spots that, singly or in combination, cover 

25.0 percent or less of the kernel.

The class Mixed Sorghum is sorghum which does not 

meet the requirements for any of the classes Sorghum, 

Tannin sorghum, or White sorghum.

Each class is divided into four numerical grades and 

U.S. Sample grade.

Sorghum

Tannin Sorghum

White Sorghum

Mixed Sorghum
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Chapter 7: Sorghum

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Grades and Grade Requirements

SORGHUM

Grade

Minimum

Limits of - Maximum Limits of -

Test weight

per bushel

(pounds)

Damaged Kernels Broken Kernels and foreign material

Heat 

(percent)

Total 

(percent)

Foreign material 

(part of total) 

(percent)

Total 

(percent)

U.S. No. 1 57.0 0.2 2.0 1.0 3.0

U.S. No. 2 55.0 0.5 5.0 2.0 6.0

U.S. No. 31 53.0 1.0 10.0 3.0 8.0

U.S. No. 4 51.0 3.0 15.0 4.0 10.0

1

 Sorghum which is distinctly discolored shall not grade any higher than U.S. No. 3.

U.S. Sample Grade

U.S. Sample grade is sorghum that does not meet the requirements for the grades U.S. Nos. 

1, 2, 3, or 4; or contains:

• 8 or more stones which have an aggregate weight in excess of 0.2 percent of the 

sample weight, 

• 2 or more pieces of glass, 

• 3 or more crotalaria seeds, 

• 2 or more castor beans, 

• 4 or more particles of an unknown foreign substance or a commonly recognized 

harmful or toxic foreign substance, 

• 8 or more cocklebur (Xanthium spp.) or similar seeds singly or in combination, 

• 10 or more rodent pellets, bird droppings, or an equivalent quantity of other animal 

filth in 1,000 grams of sorghum; 

• or has a musty, sour, or commercially objectionable foreign odor, except smut odor; 

• or Is badly weathered, heating, or otherwise of distinctly low quality.
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Chapter 7: Sorghum

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Heating

Sorghum developing a high temperature due to 

microbial activity (fermenting), insect infestation, or 

sprouting is considered heating. 

As heating progresses, sorghum will usually have a 

sour or musty odor. 

Care should be taken not to confuse sorghum that 

is heating with sorghum that is warm because of 

storage in bins, railcars, or other containers during 

hot weather.

Determine heating on evidence obtained at the 

time of sampling or on the basis of the sample as a 

whole.

Grade sorghum that is heating U.S. Sample Grade 

and record the word “Heating” in the “Remarks” 

section of the certificate.

Distinctly Low Quality

Heating Sorghum

Consider sorghum distinctly low quality when it is obviously of inferior quality and the existing 

grade factors or guidelines do not accurately reflect the inferior condition. Use all available 

information to determine whether the sorghum is of distinctly low quality. This includes 

a general examination of the sorghum during sampling and an analysis of the obtained 

sample. 

Sorghum containing two or more stones, pieces of glass, pieces of concrete, or other pieces 

of wreckage or debris which are visible to the sampler but are too large to enter the sampling 

device is considered distinctly low quality.

Sorghum that is obviously affected by other unusual conditions which adversely affect the 

quality of the sorghum and cannot be properly graded by use of the grading factors specified 

or defined in the standards is considered distinctly low quality.

Grade distinctly low quality sorghum as U.S. Sample Grade. Record the words “Distinctly 

Low Quality” and the reason why in the “Remarks” section of the certificate.
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Chapter 7: Sorghum

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General Appearance

Distinctly Discolored

Distinctly Discolored Sorghum is sorghum that has been discolored by adverse weather 

conditions to a point where a sample has a slightly gray and/or blackened appearance and 

shall be graded not higher than U.S. No. 3.

Badly Weathered 

Badly Weathered Sorghum is sorghum that has been discolored by adverse weather 

conditions to a point where many of the kernels are badly discolored and shall be graded 

U.S. Sample grade.
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Chapter 7: Sorghum

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Special Grades

Special grades identify unusual conditions in grain and are part of the grade designation. 

They do not affect the numerical or sample grade designation. The sorghum standards 

include two special grades:

Processing the Original Sample

The first step in grading a sorghum sample is to use a Boerner divider to reduce the original 

sample into:

Infested Sorghum

Infested Sorghum is sorghum that is 

infested with live weevils or other live 

insects injurious to stored grain.

Smutty Sorghum

Smutty Sorghum is sorghum that has kernels 

covered with smut spores to give a smutty 

appearance in mass or contains 20 or more 

smut balls in 100 grams of sorghum.

• A file sample of approximately

 1400 grams

• A Work portion of 

approximately 1000 grams.

File Work
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Chapter 7: Sorghum

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Boerner Divider

The Boerner divider reduces the size 

of a grain sample while maintaining its

representativeness. Each pass of the 

sample through the divider splits the

sample into two equal portions.

The Boerner Divider, consists of a 

hopper, inverted cone, and a series of

baffles directing the grain into two 

collection pans. As the valve or gate 

at the

base of the hopper is opened, gravity 

carries the grain over the cone, which

serves as a surface by which the 

kernels can separate into a single 

layer.

Arranged in a circle at the base of the cone are a series of baffles forming alternate channels 

and spaces of equal width. They are arranged in a circle at their summit and are directed 

inward and downward, the channels leading to one spout and the spaces to an opposite 

spout.

Each kernel has an equal chance of falling into a channel or a space, resulting in two nearly 

identical portions of the original sample.

When Operating the Boerner Divider:

• Check the divider for condition and 

cleanliness.

• Close the hopper valve.

• Place empty collection pans under 

the discharge spout.

• Pour the sample into the hopper.

• Open the valve quickly.

For larger samples, feed more grain into the 

hopper during the dividing process.
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Chapter 7: Sorghum

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File Sample

A “file sample” is a representative sample 

or representative portion of a sample that 

is retained for a specified period of time for 

reference or review purposes.

File samples should be of sufficient size to 

accommodate subsequent examinations or 

analysis. 

The file sample shall be an unworked portion 

(if available) of the representative sample used 

for the inspection. 

The worked portion may be retained as the final file only when insufficient sample is 

available for an unworked file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, or similar containers that allow moisture losses.

Use metal cans, plastic containers, and plastic bags to preserve the sample integrity.

Do not file samples with paper identification inserted in the grain.
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Chapter 7: Sorghum

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Determine Moisture

Moisture is the water content of sorghum as determined by an approved device before the 

removal of dockage. Record the percent of moisture on the certificate to the nearest tenth 

percent.

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. 

 DICKEY-john GAC2500 Perten AM5200-A

Basically, the instruments measure the change in capacitance of two parallel plates when 

grain is placed between them. As the moisture content within the grain increases or 

decreases so does its contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.
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Chapter 7: Sorghum

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Dockage

All matter other than sorghum that can be removed from the original sample by use 

of an approved device according to procedures prescribed in FGIS instructions. Also, 

underdeveloped, shriveled, and small pieces of sorghum kernels removed in properly 

separating the material other than sorghum.

Basis of Determination. Determine dockage on a portion of 1,000 to 1,050 grams of 

the original sample.

Carter Dockage Tester
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Chapter 7: Sorghum

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To mechanically clean the sample on the Carter dockage tester:

• Set the air control to 1.

• Set the feed control to 6.

• Insert a No. 6 sieve in the top sieve carriage.

• Insert a No. 1 sieve in the bottom sieve carriage.

• Insert the No. 6 riddle in the riddle carriage.

• Run 1,000-1,050 grams through the dockage tester.

1,000-1,050 

gram sample

Air #1

Hopper

Feed #6

#6 Sieve

#1 Sieve

#6 Riddle

Air Collection Pan

Remove threshed

& unthreshed

sorghum

FM 1

Mech. Cleaned 

Sorghum

30-gram

Subportion

Hand separate

sorghum from 

all matter other 

than sorghum

FM 2

Broken Kernels 

Collection Pan DKG

Total FM = FM 1 + 2

Removed threshed, unthreshed, and clumps of sorghum from the material that passed over 

the riddle and add to the cleaned sorghum. Dockage is all matter passing through the #1 

Sieve. 

Record the word “Dockage” and the percentage on the work record in hundredths. When 

the sample contains 1 percent or more dockage, record the percentage of dockage on the 

certificate in whole percent with a fraction of a percent disregarded. 
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Chapter 7: Sorghum

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For example:

 1.00 to 1.99 percent is recorded as 1.0 percent

 2.00 to 2.99 percent is recorded as 2.0 percent

Test Weight per Bushel

The weight per Winchester bushel is determined using an approved device according to 

procedures prescribed in FGIS instructions. A Winchester bushel is 2150.42 cubic inches or 

35.24 liters.

Test weight per bushel for sorghum is determined on the original sample before the removal 

of dockage on a portion of sufficient quantity to overflow the kettle. 

Record test weight results on the work record 

as displayed on the electronic scale or in 

whole and half pounds. Disregard fractions of 

a half pound. 

Record the test weight on the certificate in 

whole and half pounds. 

Test weight per bushel can be converted to 

kilograms per hectoliter by multiplying the 

pounds per bushel result by 1.287. Upon 

request, record the kilograms per hectoliter 

result in the “Remarks” section of the 

certificate in whole and tenths.

Filling the hopper
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Chapter 7: Sorghum

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TW Procedure

Position the hopper over the center of the kettle, making sure the hopper valve is closed. 

Pour grain into the hopper. 

Open the valve allowing the grain to overflow the kettle. Once the hopper is clear of grain 

move the hopper to the side. 

With a rounded edge striker, place it on the edge of the kettle and move the striker in three 

zigzag motions across the kettle leveling the grain. 

Move the kettle to a scale and record the test weight measurement.

Open the valve

Level the grain

Weigh the kettle
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Chapter 7: Sorghum

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Processing the Work Sample

At this point all other tests required to be performed prior to the removal of dockage have 

been made and the percentage of dockage has been determined. Now the work sample is 

ready to be divided into fractional portions for those factors determined after the removal 

of dockage, broken kernels, and foreign material. This chart illustrates how the sample is 

divided into fractional parts using the Boerner divider.

Work Sample 

1,000 – 1,050 grams 

(DKG-Free)

1st Cut

2nd Cut

1st Cut

3rd Cut

2nd Cut 2nd Cut 2nd Cut

4th Cut

3rd Cut 3rd Cut 3rd Cut

5th Cut

4th Cut 4th Cut 4th Cut

6th Cut

5th Cut 5th Cut 5th Cut

6th Cut

Handpicked 

Foreign Material

Heat-Damaged 

Kernels

Class Damaged Kernels
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Chapter 7: Sorghum

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Foreign Material

Foreign material or FM is all matter except sorghum, which passes over the number six 

riddle and all matter other than sorghum that remains on top of the number six 5/64 inch or 

1.98mm triangular-hole sieve.

Handpicked FM

From the mechanically cleaned 

sample, obtain approximately a 

30-gram representative portion. 

Handpick the 30 gram portion for 

matter other than sorghum.

Broken Kernels 

Broken Kernels

Broken kernels or BK is all matter 

that passed through the number 

six 5-64th inch triangular-hole 

sieve and over the number one 

2.5-64th inch round-hole sieve.

5/64 inch = 1.98 mm 2.5/64 = 0.99 mm
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Chapter 7: Sorghum

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Broken Kernels and Foreign Material 

Broken Kernels and Foreign Material or BNFM is the combination of broken kernels and 

foreign material. The mechanically separated broken kernels and foreign material used to 

make this calculation are in the bottom collection pan and the riddle collection pan. 

Obtain the total percentage of broken kernels and foreign material by adding the percentage 

of broken kernels, mechanically cleaned foreign material, and handpicked foreign material. 

When adding these portions, as shown in the following example add the results in 

hundredths and round the sum to the nearest tenth percent.
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Chapter 7: Sorghum

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Computing BNFM

Compute BNFM as follows:

STEP 1. Determine the Percent of dockage by dividing the Weight of dockage by the weight 

 of the original sample and multiplying the result by 100.

STEP 2. Determine the weight of the dockage-free sample by subtracting the weight of 

 dockage from the weight of original sample.

STEP 3. Determine the Percent of broken kernels or BN by dividing the Weight of broken 

 kernels by the weight of the dockage-free sample and multiplying the result by 100. 

STEP 4. Determine the Percent of mechanically separated foreign material or FM by 

 dividing the weight of FM removed by the No. 6 riddle by the weight of the 

 dockage-free sample and multiplying the result by 100.

STEP 5. Determine the Percent of handpicked FM by dividing the weight of handpicked FM 

(including other grains) by the weight of the handpicked portion and multiplying the 

 result by 100.

STEP 6. Determine the Total percent of FM by adding the Percent of handpicked FM to the 

 percent of mechanically separated FM.

STEP 7. Determine the Total percent of broken kernels and foreign material or BNFM by 

 adding the Percent BN to the total percent FM.

BNFM Example

Original sample = 1,007 grams 

Dockage = 3.81 grams 

Mechanically separated broken kernels = 54.11 grams 

Foreign material removed by the No. 6 riddle = 4.33 grams 

Handpicked portion = 29.70 grams 

Handpicked separation = 0.37 grams

Step 1. Percent dockage = 3.81 / 1,007 X 100 = 0.37 

Step 2. Dockage-free sample weight = 1,007 - 4 (3.8 rounded) = 1,003 

Step 3. Percent broken kernels = 54.11 / 1,003 X 100 = 5.39 

Step 4. Percent mechanically separated FM = 4.33 / 1,003 X 100 = 0.43

Step 5. Percent handpicked FM = 0.37 / 29.7 X 100 = 1.24

Step 6. Percent total FM = 1.24 + .43 = 1.67 (1.7 rounded)

Step 7. Percent total BNFM = 5.39 + 1.67 = 7.06 (7.1 rounded)
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Chapter 7: Sorghum

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Unattached Hulls

Unthreashed kernels of sorghum are not considered as broken kernels and foreign material.

Unattached hulls are considered as broken Kernels and foreign material.

Unattached hulls with a sliver or more of a kernel inside are not considered as broken 

kernels and foreign material.

 Unthreashed Kernels Unattached hulls

Non-grain Sorghum

Kernels of non-grain sorghum are small and have tightly clasped hulls that are shiny red, 

black, lemon yellow, or buff in color but are very rarely white in color. Kernels of non-grain 

sorghum are usually more elongated than kernels of sorghum and range in size from a large 

mustard seed to a large cockle seed.
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Chapter 7: Sorghum

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Damaged Kernels

Determine damaged kernels on a portion of 15 grams after the removal of dockage and 

broken kernels, foreign material, and other grains removed by the 5/64 inch or 1.984 mm 

triangular hole sieve.

In general, a kernel of sorghum is considered damaged for inspection and grading purposes 

only when the damage is distinctly apparent and of such character as to be recognized as 

damaged for commercial purposes. 

Damaged Kernels consists of kernels, pieces of sorghum kernels, and other grains that are:

• badly ground-damaged

• badly weather-damaged

• diseased

• frost-damaged

• germ-damaged

• heat-damaged

• insect-bored

• mold-damaged

• sprout damaged

• otherwise materially damaged

Visual Reference Images

Because of the subjectivity involved in determining 

damage, and other subjective criteria, it is critical that visual 

references are available to ensure that interpretations are 

uniformly and consistently applied throughout the national 

system. 

Color images provide a basis for communicating the 

minimum “line” for various types of damage and other 

visually determined criteria such as badly weathered, 

distinctly discolored, and class.

Ground/Weather Damage

Kernels of sorghum which have dark stains or discolorations and a rough cake-like 

appearance caused by ground and/or weather conditions are considered damaged.
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Chapter 7: Sorghum

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Insect Bored Damage

Kernels and pieces of kernels of sorghum which have been bored or tunneled by insects are 

considered damaged.

Surface Mold Damage

Kernels and pieces of kernels of sorghum with surface mold are considered damaged. 

Do not confuse mold with dark stains or discolorations caused by ground and/or weather 

conditions.

Internal Mold Damage

Kernels and pieces of kernels invaded by mold, usually in the germ area under the bran layer 

are considered damaged. The bran coat should be removed carefully because scraping too 

deeply could remove the damage. 

The determination may be performed on a pre-bleached, or in the case of weathered 

sorghum, bleached portion. Bleaching turns penetrating molds black. Sorghum germs which 

have a distinctive black spot(s), or any other color associated with mold, are considered 

damage.
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Chapter 7: Sorghum

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Sprout Damage

Kernels and pieces of kernels of sorghum in which the sprout definitely protrudes from the 

germ are considered damaged. 

The illustration shows from left to right:

Kernel 1: The germ cover is broken open with a sprout protruding from 

 the bottom.

Kernel 2: The germ cover is broken open with a sprout showing at the 

 bottom and the sprout has lifted upward extending beyond the 

 surface plane of the germ area.

Kernel 3: The germ cover is broken open with a sprout protruding from 

 the top.

Split Germ (sound)

Kernels and pieces of kernels of sorghum which have a split over the germ area, but which 

have no sprout protruding, are considered sound unless otherwise damaged.

Purple Pigment Damage

Kernels and pieces of kernels which are materially discolored by purple pigment are 

considered damaged.
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Chapter 7: Sorghum

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Germ Damage

Kernels and pieces of kernels of sorghum which, after bleaching, contain dark colored germs 

are considered damaged. Sorghum containing germ damage or suspected of containing 

germ damage must be bleached to make this determination.

Bleach Procedure 

• When bleaching sorghum to determine germ 

damage place approximately 15 grams of sorghum 

in the mixing jar. 

• Add 40 milliliters of bleach.

• Add 15 grams of KOH pellets.

• Set the stirring head on the jar, place the jar on the 

mixer, and mix for 3 minutes.

• Pour the sorghum from the mixing jar into the tea 

strainer and rinse with warm tap water to remove the 

KOH-bleach solution.

• After rinsing, lightly tap the tea strainer against the 

edge of the sink to remove excess water then gently 

press the bottom of the tea strainer on a dry paper towel to remove additional water.

• Place the sorghum on the dryer sieve and dry for one to one and a half minutes or 

until the kernels are not tacky when picked up with a pair of tweezers.

• Remove the sorghum from the drying sieve and weigh the portion.

Bleaching Safety Precautions

Safety equipment should be worn while the bleach operation is in progress and the lab area 

thoroughly cleaned once bleaching is complete.

Accidental spills should first be neutralized with vinegar before the liquid is wiped up.

Avoid mixing the potassium hydroxide KOH-bleach solution used in this test with chemical 

reagents or waste solutions associated with other tests.

When disposing of the KOH-bleach solution, wash the solution down the sink drain with large 

quantities of water.
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Chapter 7: Sorghum

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Computing Damaged Kernels

Obtain the percentage of damaged kernels by adding the percentage of germ-damaged 

kernels, other damaged kernels, and damaged kernels of grain removed by the No. 6 riddle. 

Add the results in hundredths and round the sum to the nearest tenth percent.

STEP 1. The weight of other type damaged kernels divided by the weight of sample before 

 bleaching times 100 equals the percent of other type damaged kernels.

STEP 2. 100 minus the percent of other type damaged kernels divided by 100 equals the 

 change of base factor. Do not round this result.

STEP 3. The weight of the germ damaged portion divided by the weight of the damaged 

 portion after bleaching times 100 equals the percent of germ damaged kernels.

STEP 4. The percent of germ damaged kernels times the change of base factor equals the 

 adjusted percent of germ damaged kernels.

STEP 5. The weight of damaged kernels of corn & soybeans removed by No. 6 riddle 

divided by the weight of mechanically cleaned sample equals the percent of 

damaged corn & soybeans.

STEP 6. The percent of other damaged kernels plus the adjusted percent of germ damaged 

kernels plus the percent of damaged corn & soybeans equals the percent of 

damaged kernels.

Damaged Kernels Example

Weight of mechanically cleaned sample = 949 grams 

Original weight of damaged portion = 16.10 grams 

Weight of other type damaged kernels = 2.40 grams 

Sample weight before bleaching = 13.70 grams 

Sample weight after bleaching = 11.95 grams 

Weight of germ damaged kernels = 4.33 grams 

Weight of damaged kernels of corn/soybeans 

removed by No.6 riddle = 2.50 grams

STEP 1. (2.40g / 16.10g) X 100 = 14.90% of other type damaged kernels

STEP 2. (100% - 14.90%) / 100 = 0.85 change of base factor 

STEP 3. (4.33g / 11.95g) X 100 = 36.23% germ damaged kernels

STEP 4. 0.85 X 36.23 = 30.79 adjusted percent of germ damaged kernels

STEP 5. (2.50g / 949) X 100 = 0.26 percent damaged kernels of corn/soybeans 

STEP 6. (14.90% + 30.79% + 0.26% = 45.95 (46.0 rounded) percent damaged kernels
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Chapter 7: Sorghum

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Heat Damage 

Kernels and pieces of kernels of sorghum which are materially discolored and damaged 

by heat are considered heat damaged. Determine heat-damaged kernels after the removal 

of dockage and machine-separated broken kernels and foreign material on a portion of 30 

grams. It is necessary, in most cases, to cross-section the kernels to determine if the color is 

creamy. 

The percent of heat-damaged kernels of corn and/or soybeans removed by the Number 6 

riddle during the determination of dockage, broken kernels, and foreign material is added 

to the percent of heat-damaged kernels removed from the 30-gram portion. Compute the 

percent of heat-damaged kernels of corn and/or soybeans on the basis of the weight of the 

sample after the removal of dockage and mechanically cleaned broken kernels and foreign 

material. 

Record heat-damaged kernels on the certificate to the nearest tenth percent.

Determining Class

Determine the class of sorghum by the color characteristics of the pericarps and/or subcoats 

of the kernels. 

Similarities in the bleaching methods used in the determination for sorghum germ damage 

and class determination allow inspectors to effectively use the germ damage portion to 

screen samples for class. If the bleached damage portion contains darkened kernels bleach 

a separate portion for classing purposes.

Determine the percentage of White sorghum present in a mixture before bleaching due 

to the difficulty of distinguishing between White sorghum and Sorghum after bleaching. 

Recombine the sample before proceeding.

 Tannin Sorghum Not Bleached Tannin Sorghum Bleached
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Chapter 7: Sorghum

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The bleach method for class determination is identical to that used for germ damage 

determinations, with the following exception: Use 5 grams of potassium hydroxide (KOH) 

pellets instead of 15 grams.

For Mixed sorghum, record the name and percentage of each class to the nearest tenth 

percent in the order of predominance in the “Remarks” section of the certificate.

Tannin Sorghum (Bleached)

Presence of a pigmented testa or subcoat in tannin sorghum kernels allows for the 

separation of black or dark brown tannin kernels from light colored non tannin kernels.

After bleaching, Sorghum and White sorghum kernels remain light in color while Tannin 

sorghum kernels which have a brown subcoat turn black or dark brown.

Do not confuse field damaged Sorghum or White sorghum kernels with Tannin sorghum. 

Field damage may discolor/stain the kernel making it difficult to distinguish the bleached 

Tannin sorghum from the damaged Sorghum or White sorghum.

Do not confuse Tannin sorghum having a bluish-white pericarp with damaged Sorghum or 

White Sorghum kernels. When bleached, this type of Tannin sorghum is partially discolored 

similar to damaged Sorghum or White Sorghum kernels. If necessary, quickly review an 

unbleached portion for the presence of kernels having pericarps with a bluish-white cast. If 

this type of sorghum is not present, consider the sorghum in question as Sorghum.

Sorghum with White Pericarps and Brown Subcoats have a somewhat bluish-white 

appearance. To determine the presence or absence of brown subcoats with white pericarps, 

it may be necessary to scrape small areas of the pericarp.

Other Official Criteria

Other tests that can be performed on sorghum include mycotoxin analysis and pesticide 

residue analysis.

 Mycotoxin Analysis Pesticide Residue Analysis
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Chapter 7: Sorghum

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Determine Grade Designation

• The words “or better,” when applicable, shall be shown next followed by the name of 

the class; and the applicable special grades in alphabetical order. 

• Finally the word “dockage” and the percentage thereof is shown.

• In addition, when certificating Mixed sorghum, record in the “Remarks” section of the 

certificate, in the order of predominance, the name and percentage of the classes in 

the mixture.

After completing the analysis, compare 

the results with the limits for each grade 

factor on the grade chart. The factor with 

the lowest grade designation determines 

the grade assigned to the sample. 

The Official U.S. Standards for Grain 

provide for an optional grade designation, 

commonly referred to as “or better.” 

Upon the request of an applicant, 

sorghum may be certified as U.S. No. 2 

or better, U.S. No. 3 or better, etc. An 

“or better” grade designation cannot be 

applied to a U.S. No. 1 grade designation.

Apply Grade Designation

• Use the following guidelines when 

documenting the grade.

• Show the letters “U.S.” first; 

followed by the abbreviation “No.” 

and the number of the grade or 

the words “Sample grade”;
Chapter 8: Soybean

Grain Grading Primer

Chapter 8

Soybean
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 2

Contents

Chapter 8: Soybean

Definition of Soybeans ...........................................................................................................3

Grade Requirements ..............................................................................................................4

Special Grades........................................................................................................................5

Processing the Original Sample ...........................................................................................6

File Sample..............................................................................................................................7

Basis of Determination ..........................................................................................................8

Heating ....................................................................................................................................9

Infested....................................................................................................................................9

Odor Determination ..............................................................................................................10

Moisture Determination ....................................................................................................... 11

Test Weight ...........................................................................................................................12

Garlicky Soybeans ...............................................................................................................13

Purple Mottled or Stained ....................................................................................................13

U.S. Sample Grade Factors .................................................................................................15

Infested Soybeans ................................................................................................................15

Foreign Material ....................................................................................................................16

Procedure for Determining Foreign Material .....................................................................17

Processing the Work Sample ..............................................................................................18

Class......................................................................................................................................18

Splits......................................................................................................................................19

Visual Reference Images (VRI) ...........................................................................................20

Damaged Kernels .................................................................................................................21

Types of Soybean Damage ..................................................................................................21

Heat-Damaged Kernels ........................................................................................................25

Official Criteria .....................................................................................................................25

Grade Designations..............................................................................................................26

Work Record .........................................................................................................................27
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 3

Definition of Soybeans

Soybeans are defined as:

Grain that consists of 50 percent or more of whole or broken soybeans (Glycine max (L.) merr.) 

that will not pass through an 8/64 round-hole sieve and not more than 10.0 percent of other grains 

for which standards have been established under the United States Grain Standards Act.

Soybean Classes

Soybeans are divided into two classes based color:

Yellow soybeans and Mixed soybeans. There are no subclasses.
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 4

Grade Requirements

Each class is divided into four numerical grades and U.S. Sample Grade. 

Special grades are provided to emphasize special qualities or conditions affecting the value 

and are added to and made a part of the grade designation. They do not affect the numerical 

or sample grade designation.

Grades and Grade Requirement Chart

SOYBEANS

Grade

Maximum Limits of -

Damaged Kernels Foreign 

Material

(percent)

Splits

(percent)

Soybeans of 

other colors1

(percent)

Heat

(part of total)

(percent)

Total

(percent)

 U.S. No. 1 0.2 2.0 1.0 10.0 1.0

 U.S. No. 2 0.5 3.0 2.0 20.0 2.0

 U.S. No. 3 1.0 5.0 3.0 30.0 5.0

 U.S. No. 4 3.0 8.0 5.0 40.0 10.0

U.S. Sample Grade:

U.S. Sample Grade is soybeans that:

(a) Do not meet the requirements for grades U.S. No.1, 2, 3, or 4; or

(b) Contains 4 or more stones which have an aggregate weight in excess of 0.1 percent of the 

sample weight, 1 or more pieces of glass, 3 or more crotalaria seeds (Crotalaria spp.), 2 

or more castor beans (Ricinus communis L.), 4 or more particles of an unknown foreign 

substance(s) or a commonly recognized harmful or toxic substance(s), 10 or more rodent 

pellets, bird droppings, or an equivalent quantity of other animal filth in 1,000 grams of 

soybeans, or 

(c) Contain 11 or more animal filth, castor beans, crotalaria seeds, glass, stones, or unknown 

foreign substance(s) in any combination, or

(d) Have a musty, sour, or commercially objectionable foreign odor (except garlic odor); or

(e) Are heating or otherwise of distinctly low quality.

1 Disregard for Mixed Soybeans
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 5

Special Grades

Special grades identify unusual conditions in grain and are part of the grade designation.

The soybean standards include three special grades:

• Garlicky Soybeans. Soybeans that contain five or more green garlic bulblets or an 

equivalent quantity of dry or partly dry bulblets in a 1,000-gram portion.

 Example: U.S. No. 3 Yellow Soybeans, Garlicky

• Infested Soybeans. Soybeans that are infested with live weevils or other insects 

injurious to stored grain.

 Example: U.S. No. 2 Yellow Soybeans, Infested

• Purple Mottled or Stained Soybeans. Soybeans that are discolored with pink or purple 

seed coats, dirt or a dirt-like substance, or pokeberry stains, as determined on a portion of 

400 grams with the use of an FGIS Interpretive Line Print.

 Example: U.S. No. 2 Yellow Soybeans, Purple Mottled or Stained
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 6

Processing the Original Sample

The Boerner Divider reduces the size of a grain sample while maintaining the 

representativeness of the original sample. Use the Boerner divider, or a divider that gives 

equivalent results, when reducing a sample to the portion size required for a specific test/

analysis.

When dividing the original sample the first pass through the divider will result in two equal 

portions. 

File Sample Work Portion

Original Sample • One portion is set aside as a 

“file sample”. 

• One portion is the “work portion”

which is reduced down to 

smaller work portions for use in 

determining required tests and 

analysis specific to the type of 

grain being graded.

Operating Procedures 

• Check the divider for condition 

and cleanliness

• Close the hopper valve

• Place empty collection pans under the discharge spouts

• Pour the sample into the hopper

• Open the valve quickly. For large samples, feed more grain into the hopper during the 

dividing process
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 7

File Sample

A “file sample” is a representative sample or representative portion of a sample that is 

retained for a specified period of time for reference or review purposes. File samples 

should be of sufficient size to accommodate subsequent examinations or analysis. The file 

sample shall be an unworked portion (if available) of the representative sample used for 

the inspection. The worked portion may be retained as the final file only when insufficient 

sample is available for an unworked file sample. 

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes. Do not use paper bags, fiber cartons, or similar containers that 

allow moisture losses. Use metal cans, plastic containers, and plastic bags to preserve the 

sample integrity. Do not file samples with paper identification inserted in the grain. Paper 

absorbs moisture and lowers the moisture of the grain.
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Basis of Determination

The “Basis of Determination” establishes the rules for testing/analyzing all factors. Do not 

analyze any factor until the basis for making the determination is known.

BASIS OF DETERMINATION

Lot as a Whole Factors Determined Before 

the Removal of Foreign 

Material

Factors Determined After the 

Removal of Foreign Material

Distinctly low quality

Heating

Infested

Odor

Distinctly low quality

Garlicky

Heating

Infested

Kind of Grain

Moisture

Odor

Purple Mottled or Stained

Stones

Test Weight

U.S. Sample Grade factors

Heat-damaged kernels

Damaged kernels

Odor

Soybeans of other colors

Splits

Distinctly Low Quality. The determination of distinctly low quality is made on the basis of 

the lot as a whole at the time of sampling when a condition exists that may or may not appear 

in the representative sample and/or the sample as a whole. 

Certain Quality Determinations. Each determination of rodent pellets, bird droppings, other 

animal filth, broken glass, castor beans, cockleburs, crotalaria seeds, dockage, garlic, live 

insect infestation, large stones, moisture, temperature, and unknown foreign substance(s), 

and a commonly recognized harmful or toxic substance(s) is made on the basis of the 

sample as a whole. When a condition exists that may not appear in the representative 

sample, the determination may be made on the basis of the lot as a whole at the time of 

sampling according to procedures prescribed in FGIS instructions.

All Other Determinations. Each determination of class, heat-damaged kernels, damaged 

kernels, splits, and soybeans of other colors is made on the basis of the grain when free 

from foreign material. Other determinations not specifically provided for under the General 

Provisions are made on the basis of the grain as a whole. 

Consider soybeans distinctly low quality when they are obviously of inferior quality and 

existing grade factors or guidelines do not accurately reflect the inferior condition. 
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 9

Large Debri. Soybeans containing two or more stones, pieces of glass, pieces of concrete, 

or other pieces of wreckage or debris which are visible to the sampler and too large to enter 

the sampling device are considered distinctly low quality.

Other Unusual Conditions. Soybeans that are obviously affected by other unusual 

conditions which adversely affect the quality of the soybeans and cannot be properly graded 

by use of the grading factors specified or defined in the standards are considered distinctly 

low quality.

Heating

Soybeans developing a high temperature from excessive respiration are considered heating. 

Heating soybeans, in its final stages, will usually have a sour or musty odor. Care should 

be taken not to confuse soybeans that are heating with soybeans that are warm and moist 

because of storage in bins, railcars, or other containers during hot weather.

Infested

Infested soybeans are soybeans that are infested with live weevils or other live insects 

injurious to stored grain.

The presence of any live weevil or other live insects injurious to stored grain indicates 

the probability of infestation and warns that the soybeans must be carefully examined to 

determine if they are infested. In such cases, examine the work sample and the file sample 

before reaching a conclusion as to whether or not the soybeans are infested. Do not examine 

the file sample if the work portion is insect free.

INSECT INFESTATION

Samples meeting or exceeding any one of these tolerances are infested:

2 lw, or 1 lw + 5 oli, or 10 oli

1,000-gram representative sample1

(+ file sample if needed) Lot as a Whole (Stationary) Online Sample (In-Motion)2

Submitted samples

Probed lots

D/T sampled land carriers

Probed lots (at time of sampling) Railcars under the Cu-sum

Subsamples for Sacked Grain lots

Components for Bargelots3

Components for Shiplots3

1

 Examine work portion and file sample if necessary. Do not examine file sample if work portion is insect

 free.

2

 Minimum sampling rate is 500 grams per 2,000 bushels.

3

 Minimum component size is 10,000 bushels.

Key: lw = live weevil, oli = other live insects injurious to stored grain
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 10

Live weevils include rice weevils, granary weevils, cowpea weevils, maize weevils, and 

lesser grain borers. Other live insects injurious to stored grain shall include grain beetles, 

grain moths, and larvae.

Odor Determination

Basis of Determination. Determine odor on 

evidence obtained at the time of sampling 

or on the sample either before or after the 

removal of foreign material.

Odors from Heat-Damaged Soybeans. 

When heat-damaged kernels are present, 

soybeans give off an odor very similar to 

smoke. Soybeans containing a “smoke” odor 

are considered as having a “sour” odor unless 

evidence of a fire-burnt material is present 

in the lot or the original sample. If evidence 

of a fire-burnt material is present in the lot or 

the sample, the smoke odor is considered a 

commercially objectionable foreign odor.

Commercially Objectionable Foreign Odor (COFO) are odors, except smut and garlic 

odors, foreign to grain that render it unfit for normal commercial usage. Sources of COFO 

include fumigants, oil products, smoke, fertilizer, weeds, decaying animal or plant matter, etc. 
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 11

Moisture Determination

Water content in grain as determined by an approved device according to procedures 

prescribed in FGIS instructions.

Basis of Determination. Determine moisture before the removal of dockage on a portion of 

approximately 650 grams.

The user interfaces are slightly different for the two UGMA compatible moisture meters. Use 

the keypad to choose the type of grain to analyze. 

Fill the hopper and press the load key to start the test cycle. After the moisture analysis 

is complete observe the result on the display, record it and reclaim the sample from the 

discharge tray. 

For additional information, refer to the GIPSA Moisture Handbook.

 GAC2500-UGMA Perten AM 5200-A
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 12

Test Weight

Test weight per bushel is the weight per Winchester bushel (2,150.42 cubic inches) as 

determined using an approved device. The determination for test weight is made on a 

portion of sufficient quantity to overflow the kettle. 

General Operating Procedures

1. Level and balance the test weight per 

bushel apparatus.

2. Close the hopper valve.

3. Pour the work sample into the hopper.

4. Center the hopper over the kettle.

5. Fill the kettle by opening the hopper valve 

quickly.

6. Move the hopper all the way to the left 

before proceeding. Do not jar the 

apparatus. Jarring could cause inaccurate 

results.

7. Using a standard stroker, stroke the kettle 

by holding the stroker in both hands with 

the flat sides in a vertical position. Level 

the grain in the kettle by making three full 

length, zigzag motions with the stroker.

8. Place an empty sample pan or the test weight kettle on the scale and zero the scale. 

Pour the sample from the kettle into the sample pan or place the filled kettle onto the 

scale as appropriate. Read the result from the test weight mode selected.

9. Record the test weight per bushel on the work record. 
Grain Grading Primer Chapter 8: Soybean

October 2016

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Garlicky Soybeans

Soybeans that contain five or more green garlic bulblets or an equivalent quantity of dry or 

partly dry bulblets in a 1,000-gram portion.

Green garlic bulblets are bulblets which have retained all of their husks intact.

Dry or partially dry garlic bulblets are bulblets which 

have lost all or part of their husks. Consider bulblets 

with cracked husks as dry.

NOTE: Wild onion, sometimes referred to as “crow 

garlic”, is considered as garlic. Three dry or partly 

dry garlic bulblets are equal to one green bulblet.

Purple Mottled or Stained

Soybeans with pink or purple seed coats as determined on a portion of approximately 400 

grams with the use of an FGIS Interpretive Line Print.

Purple mottled or stained is an appearance factor in soybeans and when sufficient amounts 

of discolored soybeans are found, the soybeans are considered purple mottled or stained.

Soybeans Discolored by the Growth of a Fungus

Soybeans discolored by a fungus have seed coats that are discolored pink or purple. This 

type of discoloration is caused by the growth of a fungus and may cover all or part of the 

kernel. Soybeans exhibiting this type of discoloration shall be considered purple mottled or 

stained. 
Grain Grading Primer Chapter 8: Soybean

October 2016

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Soybeans Discolored by Dirt or a Dirt-Like Substance

This type of discoloration is caused by dirt or similar matter and includes nontoxic 

substances. Dirt, dirt-like substances, or other nontoxic substances are substances which 

can be readily removed by water. Soybeans exhibiting this type of discoloration shall be 

considered purple mottled or stained. 

Soybeans Purple Mottled or Stained by Pokeberry Stain

Soybeans with seed coats discolored by pokeberry stain are considered purple mottled or 

stained. 
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 15

U.S. Sample Grade Factors

Basis of Determination. Determine additional U.S. Sample Grade criteria before the 

removal of foreign material based on a work portion of 1,000 - 1,050 grams.

Soybeans inoculated with a seed 

treatment which is toxic should not be 

confused with soybeans stained by 

pokeberry juice which is not toxic.

Consider identifiable pieces of 

grain, processed grain products 

such as soybean meal, sorghum 

grits, corn meal, bulgur, etc., or feed 

pellets in grain as foreign material. 

Unidentifiable materials or material 

unrelated to grain shall function as 

"unknown foreign substance". 

Toxic Seeds Animal Filth

(Crotalaria)

If it is difficult to visually determine soybeans stained by pokeberry juice from those stained 

by a seed treatment, the following procedures may be used:

• Place discolored soybean kernels into a 100 x 15 mm petri dish.

• Use an eyedropper to add enough hydrochloric acid (HCL) to cover the soybeans. Care 

should be taken not to get HCL in the eyes or on the skin.

• If the soybeans are stained with pokeberry juice, the HCL solution (0.1 N) will remove 

the stain from the seed coat and the soybeans are not graded U.S. Sample Grade. If the 

soybeans are stained with a toxic seed treatment, the HCL solution will not remove the 

stain from the seed coat and the soybeans are graded U.S. Sample Grade.

Infested Soybeans

Infested soybeans are soybeans that are infested with live 

weevils or other live insects injurious to stored grain.

The presence of any live weevil or other live insects injurious to stored grain indicates 

the probability of infestation and warns that the soybeans must be carefully examined to 

determine if they are infested. In such cases, examine the work sample and the file sample 

before reaching a conclusion as to whether or not the soybeans are infested. Do not examine 

the file sample if the work portion is insect free.

Live weevils include rice weevils, granary weevils, cowpea weevils, maize weevils, and 

lesser grain borers. Other live insects injurious to stored grain shall include grain beetles, 

grain moths, and larvae. 
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 16

Foreign Material

All matter that passes through an 8/64 round-hole sieve and all matter other than soybeans 

remaining in the sieved sample after sieving according to procedures prescribed in FGIS 

instructions.

Coarse Foreign Material consists of the following:

• Whole kernels of corn. Whole kernels of corn are 

kernels with one-fourth or less of the kernel removed.

• Cockleburs.

• Sticks if the following criteria are met:

(a) Approximately 1 inch or more in length.

(b) Approximately 1/2 inch or more with a 

thickness of 5/32 of an inch (width of the largest 

soybean slotted sieve).

• Pods (one-half pod or more). If pods contain 

soybeans, remove the soybeans and return to sample.

• Other coarse foreign material may include but is not limited to corn cobs, large feed 

pellets, pieces of dirt larger than soybeans, sweet corn, and edible beans that are 

generally larger than soybeans.

Fine Foreign Material consists of the following:

• Broken kernels of corn with more than one-fourth of the kernel 

removed.

• Popcorn, sunflower seed, and edible beans that are generally 

equal to or smaller than soybeans.

• Star thistles, star burs, sandburs, morning glory, and kinghead 

seeds.

• Sticks not meeting the criteria for coarse foreign material.

• Soybean pods less than one-half the total pod. Any other 

material too small to function as coarse foreign material.

Soybean hulls which are not removed by the 3.175 mm (8/64) round-hole sieve are not 

considered foreign material
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Procedure for Determining Foreign Material

Step 1: Coarse Foreign Material

Handpick the 1,000 – 1,050 gram portion for coarse foreign material. 

Step 2: Fine Foreign Material

a. Cut down the cleaned sample (free of 

coarse foreign material) to a portion of 

125 grams.

b. Using an approved shaker or hand sieve,

sieve (5 strokes) the 125-gram 

portion with an 8/64’’ (3.175 mm) 

round-hole sieve.

c. Handpick the material other than

soybeans from the material remaining 

on the 8/64’’ sieve and add it to the fine 

foreign material.
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October 2016

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Soybean hulls which remain on the 8/64’’

sieve are not considered foreign material.

NOTE: An 8/64 x 3/4 (3.175 x 19.050 mm) 

or 9/64 x 3/4 (3.572 x 19.050 mm) oblonghole sieve, or 10/64 x 3/4 (3.969 x 19.050 

mm) oblong-hole sieve may be mounted 

on top of the 8/64’’ round-hole sieve and 

used an aid in separating splits. When 

a sieve is used as an aid, the material 

remaining on top of the 8/64’’ round-hole 

sieve and the material remaining on top of 

the sieve used as an aid is analyzed for 

additional fine foreign material.

Processing the Work Sample

At this point, determinations have been made for those tests that are performed prior to the 

removal of foreign material and the percentage of foreign material has been determined. 

Using the Boerner Divider divide the work sample into the following fractional portions for 

those determinations required after the removal of the foreign material. 

APPROXIMATE ANALYTICAL PORTION SIZES

Factors Grams

Damaged kernels

Foreign material

Heat-damaged kernels

Kind of grain1

Soybeans of other colors

Splits

125

125

125

125

125

125

1 Factor determined before the removal of foreign material.

Class

Determine class by the color characteristics of the kernels on a portion of 125 grams after the 

removal of foreign material. There are two classes of soybeans:

Yellow Soybeans are soybeans that have yellow or green seed coats and which in cross 

section are yellow or have a yellow tinge, and may include not more than 10.0 percent of 

soybeans of other colors.

Mixed Soybeans are soybeans that do not meet the requirements of the class Yellow soybeans.
Grain Grading Primer Chapter 8: Soybean

October 2016

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Soybeans of Other Colors

Soybeans of other colors is not a class of soybeans.

Soybeans that have green, black, brown, or bicolored seed coats. Soybeans that have green 

seed coats will also be green in cross section. Bicolored soybeans will have seed coats of 

two colors, one of which is brown or black, and the brown or black color covers 50 percent 

of the seed coats. The hilum of a soybean is not considered a part of the seed coat for this 

determination. 

Soybeans of Other Colors

Soybeans with green seed coats that are yellow when cross sectioned are considered Yellow 

soybeans. 

Yellow or Green soybeans with distinct black or brown pigmented streaks or splotches 

covering 50 percent or more of the seed coat are considered bicolored soybeans.

Black or Brown soybeans with distinct yellow or green pigmented streaks or splotches 

covering 50 percent or more of the seed coat are considered bicolored soybeans.

Splits

Soybeans with more than one-fourth of the bean removed and that are not damaged.

Note: A smaller portion size (approximately 60 grams) may be used for the analysis of splits 

when a sample contains approximately 50 percent or more of whole soybeans that pass 

through a 10/64 oblong-hole sieve.

The following sieves are used to determine splits: 

• 8/64 x 3/4 (3.175 x 19.050 mm) or 9/64 x 3/4 (3.572 x 19.50 mm) oblong-hole; or 

• 10/64 x 3/4 (3.969 x 19.50 mm) oblonghole hand sieve 

Use these sieves in conjunction with the 8/64 inch round-hole sieve used to determine 

foreign material. 

All splits are not separated by sieving. Therefore, the material remaining on top of the sieve 

and the material that passed through the sieve have to be examined for splits.
Grain Grading Primer Chapter 8: Soybean

October 2016

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Since splits are normally separated during the determination of foreign material, the weight of 

the foreign material must be subtracted from the weight of the representative portion before 

calculating the percentage of splits.

Visual Reference Images (VRI) 

Because of the subjectivity involved in determining damage and other criteria, it is critical that 

visual references are available to ensure that interpretations are uniformly and consistently 

applied throughout the national system. 

Visual Reference Images provide a basis for communicating the minimum “line” for various 

types of damage and other visually determined criteria.

For complete inventory and description of the VRI visit GIPSA’s website.
Grain Grading Primer Chapter 8: Soybean

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Damaged Kernels

Soybeans and pieces of soybeans that are badly ground-damaged, badly weathered 

damaged, diseased, frost-damaged, germ-damaged, heat-damaged, insect-bored, 

molddamaged, sprout-damaged, stinkbug-stung, or otherwise materially damaged. Stinkbugstung kernels are considered damaged kernels at the rate of one-fourth of the actual 

percentage of the stung kernels.

Note: A smaller portion size (approximately 60 grams) may be used for the analysis of 

damaged kernels when a sample contains approximately 50 percent or more of whole 

soybeans that pass through a 10/64 oblong-hole sieve.

Types of Soybean Damage

A soybean kernel is considered damaged for inspection and grading purposes when the 

damage is distinctly apparent and of such character as to be recognized as damaged for 

commercial purposes.

Badly Ground and/or Weather Damage

Soybeans and pieces of soybeans in which the seed coats are discolored to the extent that 

the area of coverage and intensity is equal to or greater than shown. 

Weather Damage (Gray/Black)

Soybeans that contain gray/black discoloration on the seed coat with the area of coverage 

and intensity equal to or greater than shown are considered damaged. 
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Damaged by Heat

Soybeans and pieces of soybeans which have been damaged by heat and the area of 

coverage and intensity is equal to or greater than shown.

Green Damage

Soybeans and pieces of soybeans that are discolored green with an area of coverage and 

intensity equal to or greater than shown.

Frost Damage (Waxy)

Soybeans and pieces of soybeans which have a glassy, wax-like appearance.

Immature (Wafer)

Soybeans and pieces of soybeans which are immature and have a thin, flat, wrinkled, or 

wafer like appearance. Immature soybeans are considered sound unless otherwise damage.
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Insect Bored Kernels

Soybeans and pieces of soybeans with obvious weevil bored holes indicating the possible 

inner presence of insects, insect webbing, or insect refuse.

Mold Damage

A. Invaded by Mold: Soybeans that are discolored, elongated, or misshapen, and contain 

white or gray mold on the seed coat equal to or greater than combined amounts shown.

B. Surface Mold Growth: Soybeans with little or no apparent deterioration having a milky 

white or grayish crusty growth caused by downy mildew.

Mold Damage (Pink)

Soybeans and pieces of soybeans that exhibit a pink discoloration (caused by fungal activity) 

on the seed coat with an area of coverage and intensity equal to or greater than shown.

Sprout Damage

Soybeans and pieces of soybeans in which the sprout protrudes from the seed coat equal to 

or greater than shown are considered damage.
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Stinkbug or Insect Stung Kernels

Soybeans or pieces of soybeans which show an indentation or discoloration on the seed 

coat. To determine the extent of damage, it is generally necessary to cross-section the 

soybean.

Shriveled and Wrinkled

Whole, sound soybeans passing through a 10/64” x 3/4” slotted sieve, and remaining on top 

of a 8/64” round-hole sieve that are wrinkled to the minimum extent shown are considered 

shriveled and wrinkled.

White Hilum

Hilum color: A. white, yellow, clear*; B. buff; C. brown; D. imperfect black; E. black

*These descriptors are used interchangeably and represent the only hilum color considered a 

“white hilum” soybean.

NOTE: For information purposes only.
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October 2016

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Heat-Damaged Kernels

Soybeans and pieces of soybeans which are materially discolored and damaged by heat with 

an area of coverage and intensity equal to or greater than shown.

SB-5.0 Heat Damage (Materially Damaged/Heating)

Official Criteria 

Official criteria factors are determined only on request and do not affect the grade 

designation. For complete instructions on analyzing and/or determining official criteria refer 

to 

• Oil and/or Protein. An applicant may request analysis for oil, protein, or oil and protein 

content.

Basis of Determination. For complete instructions on analyzing oil and/or protein content 

refer to GIPSA’s NIRT Handbook.

• Sclerotinia Sclerotiorum. The fungus S. sclerotiorum causes a stem disease (stem rot) 

in soybeans which results in large black growths (sclerotinia) on the stem and pods. Seeds 

may occasionally become infected within diseased pods. If infected early, the seeds are 

flattened and badly shriveled and are sometimes replaced by sclerotinia.

Basis of Determination. Examine the work portion, 1,000 – 1,050 grams, for the presence 

of sclerotinia.

• Black Soybeans. Soybeans that have black seed coats.

Basis of Determination. Determine the percentage of black soybeans on the color 

characteristics of the kernels on a 125-gram portion after the removal of foreign material.

• Seed Sizing. Consists of a measurement of soybeans passing through or

remaining on top of a sieve(s) size specified by the applicant for service.

Basis of Determination. Determine seed sizing on a portion of 125 grams after the removal 

of foreign material, using the Mechanical Sieving Method or Hand Sieving Method. Refer to 

GIPSA’s Grain Inspection Handbook II - Soybeans for complete instructions.

• Seed Count. A measurement of the number of soybeans contained in a specified weight 
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 26

(i.e., number of soybeans per 1,000 grams, one pound, etc.)

Basis of Determination. For complete instructions on analyzing oil and/or protein content 

refer to GIPSA’s NIRT Handbook.

• White Hilum. A test to determine the percent of whole soybeans with clear white hilum. 

Upon request, tests for other hilum colors (buff, brown, etc.) can be provided. 

Basis of Determination. Determine the percentage of clear white hilum on a portion of 

125 grams after the removal of foreign material and non-whole soybeans (soybeans with 

more than one-fourth of the bean removed).

• Cracked Seedcoats. A test to determine the percent of cracked seedcoats of sound 

soybeans.

Basis of Determination. Determine the percentage of cracked seedcoats on a portion 

of 125 grams after the removal of foreign material and damaged kernels. Soybeans with 

cracked seedcoats shall be whole (three-fourths or more of a whole soybean) sound 

soybeans which have readily discernable cracked seedcoats, or have all or part of the 

seedcoat removed.

• Shriveled and Wrinkled Soybeans. Whole non-damaged soybeans with an atypical size 

and appearance that pass through a 10/64” x 3/4” oblong-hole sieve and remain on top of 

the 8/64” round-hole sieve.

Basis of Determination. Determine shriveled and wrinkled soybeans after the removal of 

foreign material on a representative portion of 125 grams.

Grade Designations

After completing the analysis, compare the results with the limits for each grade factor 

specified in the Grades and Grade Requirement Table for Soybeans. 

Use the following guidelines when assigning grades:

• The letters “U.S.”;

• The abbreviation “No.” and the number of the grade or the words “Sample Grade”;

• The words “or better,” when applicable, shall be shown next;

• The name of the class; and

• The applicable special grades in alphabetical order.

For Mixed soybeans, record the percentage of Yellow soybeans and soybeans of other 
Grain Grading Primer Chapter 8: Soybean

October 2016

Page 8 - 27

colors to the nearest tenth percent on the work record and in the “Remarks” section of the 

certificate. 

 Example: U.S. No. 2 Yellow Soybeans

 U.S. No. 3 Mixed Soybeans

 In “Remarks”: Yellow Soybeans 75.4%

 Soybeans of other colors 24.6%

 

 U.S. No. 2 or better Yellow Soybeans

Work Record

FGIS personnel use Forms FGIS-920, “Grain Sample Ticket,” (example below) FGIS-918, 

“Sample Pan Ticket,” FGIS-919, “Sampling Ticket,” or FGIS-921, “Inspection Log,” to record 

all sampling and inspection information.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

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Chapter 9: Sunflower Seed

Grain Grading Primer

Chapter 9

Sunflower Seed
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 2

Contents

Chapter 9: Sunflower Seed

Sunflower Seed Definition .....................................................................................................4

Identifying Sunflower Seed ...................................................................................................5

Grade Requirements ..............................................................................................................6

Sample Grade .........................................................................................................................6

Special Grade .........................................................................................................................6

Heating ....................................................................................................................................7

Distinctly Low Quality ............................................................................................................7

Processing the Original Sample ...........................................................................................8

Boerner Divider.......................................................................................................................9

File Sample............................................................................................................................10

Use Moisture Proof Containers ...........................................................................................10

Determine Moisture .............................................................................................................. 11

Odor Determination ..............................................................................................................12

Check for Insects..................................................................................................................13

Live Weevils ..........................................................................................................................13
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October 2016

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Other Live Insects ................................................................................................................ 14

Check for Sample Grade ...................................................................................................... 15

Foreign Material .................................................................................................................... 16

Dockage Tester Calibration ................................................................................................. 16

Mechanical Cleaning ............................................................................................................ 18

Handpicking .......................................................................................................................... 19

Processing the Work Sample .............................................................................................. 20

Test Weight per Bushel ....................................................................................................... 21

Damaged Sunflower Seed ................................................................................................... 22

Pearling and Aspiration ....................................................................................................... 23

Heat Damage & Damaged-by-Heat...................................................................................... 23

Dehulled Seed ....................................................................................................................... 24

Other Official Criteria ........................................................................................................... 25

Determine Admixture ........................................................................................................... 26

Grade Designations.............................................................................................................. 27

Documenting the Grade ....................................................................................................... 28
Grain Grading Primer Chapter 9: Sunflower Seed

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Sunflower Seed Definition

Sunflower seed is defined as: Grain that, before the removal of foreign material, consists of 

50.0 percent or more of cultivated sunflower seed, and not more than 10.0 percent of other 

grains for which standards have been established under the United States Grain Standards 

Act. 

There are no classes or subclasses in sunflower seed. Normally, a visual appraisal of the 

sample is sufficient to determine if it meets the definition of sunflower seed. However, if an 

analysis is necessary, make the determination before the removal of foreign material, on a 

portion of 75 grams.
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October 2016

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Identifying Sunflower Seed

Cultivated Sunflower Seed is sunflower 

seed grown for oil content. Cultivated 

sunflower seed includes samples or lots 

comprised of mixtures of confectionery and 

oil type seeds or pure confectionery seed, 

provided the mixture or pure confectionery 

seed are presented for inspection as 

sunflower seed marketed for oil content. 

The term seed in this and other definitions 

related to sunflower seed refers to both 

the kernel and hull. The Hull or Husk is 

the ovary wall of the sunflower seed. The 

Kernel or Meat is the interior contents of 

the sunflower seed that are surrounded by 

the hull. The terms “kernel” and “meat” are 

used synonymously. 

Except for the definition of admixture, a 

hull does not constitute a sunflower seed. 

According to the definition, a sunflower 

seed can be either the hull and the kernel, 

or just the kernel. Please note that if 

the hull and kernel together are taken 

as a sunflower seed, the size of either is 

irrelevant as long as they are connected.

Cultivated Sunflower Seed

Confectionery Sunflower Seed
Grain Grading Primer Chapter 9: Sunflower Seed

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Grade Requirements

Sunflower seed is divided into two U.S. numerical grades and U.S. Sample grade. The 

factors affecting sunflower seed grades include: test weight, heat damaged kernels, total 

damage, and de-hulled seed.

SUNFLOWER SE ED

Grade

Minimum Limits of - Maximum Limits of -

Test weight per 

bushel (pounds)

Damaged Kernels

Dehulled Seed 

(percent)

Heat

Damaged

(percent)

Total

(percent)

U.S. No. 1 25.0 0.5 5.0 5.0

U.S. No. 2 25.0 1.0 10.0 5.0

Sample Grade

Sunflower seed that does not meet the requirements for the grades U.S. Nos. 1 and 2; 

or contains stones, glass, crotalaria seeds, castor beans, particles of an unknown foreign 

substance or a commonly recognized harmful or toxic foreign substance, rodent pellets, bird 

droppings, or other animal filth, or has a musty, sour, or commercially objectionable foreign 

odor; or Is heating or otherwise of distinctly low quality, is sample grade.

 Animal Filth Crotalaria Castor Bean Glass Stones
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

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Special Grade

There is one special grade in sunflower seed. The special grade “Infested” is sunflower 

seed that is infested with live weevils or other insects injurious to stored grain. Determine 

infestation on the lot as a whole and/or sample as a whole. 

When applicable, the word “Infested” is included in the grade designation. 

For example: U.S. No. 1 sunflower seed, Infested

The special grade does not affect the numerical or sample grade designation.

Heating

Sunflower seed developing a high temperature due to microbial activity (fermenting), insect 

infestation, or sprouting is considered heating. As heating progresses, sunflower seed will 

usually develop a sour or musty odor. 

Care should be taken not to confuse Sunflower seed that is heating with Sunflower seed that 

is warm because of storage in bins, railcars, or other containers during hot weather.

Determine heating on evidence obtained at the time of sampling or on the basis of the 

sample as a whole.

Grade heating Sunflower seed U.S. Sample Grade and record the word “Heating” in the 

“Remarks” section of the certificate.

Distinctly Low Quality

Consider sunflower seed distinctly low quality when it is obviously of inferior quality and the 

existing grade factors or guidelines do not accurately reflect the inferior condition. Use all 

available information to determine whether the sunflower seed is of distinctly low quality. This 

includes a general examination of the sunflower seed during sampling and an analysis of the 

obtained sample(s). Sunflower seed containing two or more stones, pieces of glass, pieces 

of concrete, or other pieces of wreckage or debris which are visible to the sampler but are too 

large to enter the sampling device is considered distinctly low quality.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

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Sunflower seed that is obviously affected by other unusual conditions which adversely affect 

the quality of the sunflower seed and cannot be properly graded by use of the grading factors 

specified or defined in the standards is considered distinctly low quality.

Grade distinctly low quality as U.S. Sample Grade. Record the words “Distinctly Low Quality” 

and the reason(s) why in the “Remarks” section of the certificate.

Processing the Original Sample

The first step in grading a sunflower seed sample is to use a Boerner divider to reduce the 

original sample into:

• A file sample of approximately 950 grams.

• A Work portion of approximately 600 grams.

 FILE WORK
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Boerner Divider

The Boerner divider reduces the size of a grain sample while maintaining its representativeness.

Each pass of the sample through the divider splits the sample into two equal portions. The 

Boerner Divider, consists of a hopper, inverted cone, and a series of baffles directing the 

grain into two collection pans.

As the valve or gate at the base of the hopper is opened, gravity carries the grain over 

the cone, which serves as a surface by which the kernels can separate into a single layer. 

Arranged in a circle at the base of the cone are a series of baffles forming alternate channels 

and spaces of equal width. They are arranged in a circle at their summit and are directed 

inward and downward, the channels leading to one spout and the spaces to an opposite 

spout. Each kernel has an equal chance of falling into a channel or a space, resulting in two 

nearly identical portions of the original sample.

When Operating the Boerner Divider:

• Check the divider for condition and cleanliness.

• Close the hopper valve.

• Place empty collection pans under the discharge spout.

• Pour the sample into the hopper.

• Open the valve quickly.

For larger samples, feed more grain into the hopper during the dividing process.
Grain Grading Primer Chapter 9: Sunflower Seed

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File Sample

A “file sample,” is a representative sample or 

representative portion of a sample that is retained 

for a specified period of time for reference or review 

purposes.

File samples should be of sufficient size to 

accommodate subsequent examinations or analysis. 

The file sample shall be an unworked portion (if 

available) of the representative sample used for the 

inspection. 

The worked portion may be retained as the final 

file only when insufficient sample is available for an 

unworked file sample.

Use Moisture Proof Containers

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes.

Do not use paper bags, fiber cartons, or similar containers that allow moisture losses. Use 

metal cans, plastic containers, and plastic bags to preserve the sample integrity. 

Do not file samples with paper identification inserted in the grain. Paper absorbs moisture 

and lowers the moisture of the grain.
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Determine Moisture

Moisture is the water content in grain.

Determine moisture before the removal of foreign material on approximately 400 grams.

The DICKEY-john GAC2500-UGMA and the Perten AM5200-A are the designated official 

moisture meters for performing moisture analysis in grains. 

 DICKEY-john GAC2500 Perten AM5200-A

Basically, the instruments measure the change in capacitance of two parallel plates when 

grain is placed between them. As the moisture content within the grain increases or 

decreases so does its contribution to capacitance, known as its dielectric constant. 

The instruments also measure sample density and temperature and perform automatic 

corrections for those parameters.

Calibration equations have been developed to convert these properties into precise moisture 

percentages for each grain measured by the instruments.

The test they perform takes about 30 seconds to complete and is a simple and accurate way 

to obtain moisture analysis in the field.

Certify moisture to the nearest tenth percent.
Grain Grading Primer Chapter 9: Sunflower Seed

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Odor Determination

Determine odor on evidence obtained at 

the time of sampling or on the sample either 

before or after the removal of mechanically 

cleaned foreign material. Odors are classified 

as OK, Musty, Sour, or COFO (commercially 

objectionable foreign odors). 

Grade sunflower seed containing a “distinct” 

musty, sour, or commercially objectionable 

foreign odor as U.S. Sample grade. Record 

the words “Musty,” “Sour,” or “Commercially 

Objectionable Foreign Odor” in the “Remarks” 

section of the certificate.

Musty odors indicate the presence of fungal activity in the grain and are generally 

characterized as an earthy smell. 

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are 

often characterized as an acrid, boot pit or pigpen smell. 

Commercially objectionable foreign odors are odors foreign to grain that render it unfit for 

normal commercial usage. 

Fumigant or insecticide odors are considered commercially objectionable foreign odors if 

they linger and do not dissipate. 

When heat-damaged kernels are present, sunflower seed gives off an odor very similar 

to smoke. Sunflower seed containing a “smoke” odor is considered as having a “sour” 

odor unless evidence of a fire-burnt material is present in the lot or the original sample. 

If evidence of fire-burnt material is present in the lot or the sample, the smoke odor is 

considered a commercially objectionable foreign odor.
Grain Grading Primer Chapter 9: Sunflower Seed

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Check for Insects

Infested sunflower seed is sunflower seed that is infested with live weevils or other live 

insects injurious to stored grain. The presence of any live weevil or other live insects injurious 

to stored grain indicates the probability of infestation and warns that the sunflower seed must 

be carefully examined to determine if it is infested. 

In such cases, examine the work sample and the file sample before reaching a conclusion as 

to whether or not the sunflower seed is infested. Do not examine the file sample if the work 

portion is insect free.

Determine infestation on the lot as a whole and/or sample as a whole. Samples meeting or 

exceeding any one of these tolerances are infested: 

2 live weevils

1 live weevil + 5 other live insects

10 other live insects

When applicable, record the word “Infested” on the certificate.

Live Weevils

Live weevils include rice weevils, granary weevils, maize weevils, cowpea weevils, and 

lesser grain borers. 

Rice

Weevil

Granary

Weevil

Maize

Weevil

Cowpea

Weevil

Lessor Grain

Borer
Grain Grading Primer Chapter 9: Sunflower Seed

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Other Live Insects

Other live insects injurious to stored grain include grain beetles, sunflower moths, banded 

sunflower moths, Indian meal moths, grain moths, and larvae.

Angoumois

Grain Moth

Indian Meal

Moth

Red Flour

Beetle

Flat Grain

Beetle

Gray Sunflower Seed Weevil

Larvae of the red or gray sunflower seed weevil are small, white, legless grubs approximately 

1/8 inch in size that wander among sunflower seeds. When disturbed, these larvae curl into 

a ball and remain motionless for minutes. They chew out from inside the sunflower seed and 

cannot re-infest the seed in storage. Consequently, lots containing sunflower seed weevil 

larvae are not considered infested. Sunflower seed weevil larvae are considered foreign 

material.
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Check for Sample Grade

Determine U.S. Sample grade criteria before the removal of foreign material based on a work 

portion of 600 grams. Sunflower seed is graded Sample Grade if it contains:

 Animal Filth Crotalaria Castor Bean Glass Stones

• 8 or more stones which have an aggregate weight in excess of 0.20 percent of the 

sample weight, 

• 2 or more pieces of glass, 

• 3 or more crotalaria seeds, 

• 2 or more castor beans, 

• 4 or more particles of an unknown foreign substance or a commonly recognized harmful 

or toxic foreign substance, 

• 10 or more rodent pellets, bird droppings, or an equivalent quantity of other animal filth, 

per 600 grams of sunflower seed;

Consider identifiable pieces of grain, processed grain products (e.g., soybean meal, sorghum 

grits, corn meal, bulgur, etc.), or feed pellets in grain as foreign material. Unidentifiable 

materials or material unrelated to grain shall function as “unknown foreign substance.” 

Grade sunflower seed U.S. Sample grade when one or more of the limits are exceeded. 

Record the reasons why in the “Remarks” section of the certificate. Record count factors to 

the nearest whole number.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 16

Foreign Material

Foreign Material consists of all matter other than whole sunflower seeds containing kernels 

that can be removed from the original sample by use of a Carter Dockage Tester and by 

handpicking a portion of the sample. Determine foreign material on 600 grams of the original 

sample.

Dockage Tester Calibration

Calibrate each dockage tester that will be used to 

inspect sunflower seed prior to testing sunflower seed 

and whenever the internal air-control adjustment is 

changed. Only dockage testers that are in tolerance 

for wheat may be calibrated for sunflower seed. 

The National Grain Center will provide six sunflower 

seed calibration samples for calibrating each official 

field dockage tester. Empty the first sample into a 

hand sieve bottom pan and mix it thoroughly. The light 

air dockage may tend to cling to the containers; make 

an extra effort to retain all components of the sample. 

Do not weigh the samples. Calculations shall be based 

on 600 grams.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 17

• Turn the tester on. Allow the machine 

to run until the riddle separation has 

cleared the riddle. Turn the machine 

off.

• Clean the riddle and place any 

material that was lodged in it into its 

separation pan. Clean the sieves and 

place any material lodged in them 

into the clean sample. Put the air, 

riddle, over-the-bottom sieve, and 

through-the-bottom sieve separations 

into individual pans. Weigh each 

separation and record the results to 

0.01 g.

• Compare the weight of the air 

separation to the known air separation 

weight for that sample and adjust the 

air to “0” deviation. Test the second 

and third samples in the same manner 

as the first. After each test, correct the 

air setting as needed. 

• After the dockage tester is calibrated, 

mark the air setting. Test the fourth, 

fifth, and sixth samples in the same 

manner as the first three. If the 

average variation of the test results is 

within ± 0.5 percent total dockage of 

TSD’s results, the tester calibration is 

acceptable.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 18

Mechanical Cleaning

If the percentage of foreign material is requested, use the following procedure. 

First mechanically clean the sample using the Carter Dockage Tester using the following 

settings: 

• Insert the No. 3 sieve in the top sieve carriage, 

• no sieve in the middle carriage, 

• the No. 8 sieve in the bottom sieve carriage and 

• insert the oilseed riddle.

• Set the air at the standardized setting and the feed control to 7.5.

600 - 650

gram Sample

Air 

Air Collection Pan Std

FM 1

Hopper

Feed #7.5

#3 Sieve

No Sieve

#8 Sieve

FM 3

Total FM = FM 1 + 2 + 3 + Handpicked

Oil Seed Riddle

Remove

SF Seeds

FM 2

Mech. Cleaned 

SF Seed

75-gram

Subportion

Hand separate

all matter

other than

sunflower seed

Handpicked FM
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 19

Run 600 grams through the dockage tester. 

Remove sunflower seeds from the material 

removed by the riddle and add to the 

cleaned sunflower seed.

The aspirated material in the air collection 

pan is foreign material, the material over 

the riddle, except for sunflower seeds, is 

foreign material, and the material in bottom 

collection pan is foreign material. 

Calculate the mechanically separated 

foreign material.

Handpicking

Cut down the cleaned sample to a portion 

of 75 grams. 

Handpick the 75-gram portion for all matter 

other than sunflower seed. 

Calculate the handpicked foreign material.

 

Add the percent of mechanically cleaned 

foreign material and the percent of 

handpicked foreign material and report 

to the nearest whole and half percent as 

follows:

0.00 to 0.24 = 0.0 percent

0.25 to 0.74 = 0.5 percent

0.75 to 1.24 = 1.0 percent, etc.

Mechanically Seperated FM

Handpicked FM
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 20

Processing the Work Sample

At this point, determinations have been made for those factors determined before the 

removal of foreign material and the percentage of foreign material has been determined.

Now divide the work sample into fractional portions for those determinations required after 

the removal of foreign material.

600 – 650 gram

Work Sample

Mechanically Separated FM

1st Cut

2nd Cut

1st Cut

3rd Cut

2nd Cut

4th Cut

3rd Cut

4th Cut

Handpicked FM

Kind of Grain

Dehulled Seed Heat-Damaged

Damaged
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 21

Test Weight per Bushel

The weight per Winchester bushel is 

determined using an approved device 

according to procedures prescribed in 

FGIS instructions. A Winchester bushel is 

2150.42 cubic inches or 35.24 liters.

Determine test weight per bushel after the 

removal of mechanically separated foreign 

material on a portion of sufficient quantity to 

overflow the kettle. 

Position the hopper over the center of the 

kettle, making sure the hopper valve is 

closed. Pour grain into the hopper. 

Open the valve allowing the grain to 

overflow the kettle. Once the hopper is 

clear of grain move the hopper to the side. 

With a rounded edge striker, place it on 

the edge of the kettle and move the striker 

in three zigzag motions across the kettle 

leveling the grain. 

Move the kettle to a scale and record the test weight measurement.

Record test weight results on the work record as displayed on the electronic scale or in whole 

and half pounds. Disregard fractions of a half pound. 

Record the test weight on the certificate in whole and half pounds. 

If requested, convert the pounds per bushel result to kilograms per hectoliter by multiplying 

the result by 1.287. Record the result in the “Remarks” section in whole and tenths.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 22

Damaged Sunflower Seed

Damaged sunflower seed is seed and pieces of sunflower seed that are:

Sunflower Seeds containing surface mold on one or both sides are considered damaged, 

if the coverage is equal to or greater than the amount of mold shown on both seeds 

collectively.

• Badly ground damaged

• Badly weathered

• Diseased 

• Frost damaged

• Heat damaged

• Damaged-by-heat

• Mold damaged

• Sprout damaged

• Otherwise materially damaged

In general, sunflower seed is considered to be damaged for inspection and grading purposes 

only when the damage is distinctly apparent and of such character as to be recognized as 

damaged for commercial purposes. Insect bored kernels are not considered damaged. 

After the removal of mechanically separated foreign material, examine a 30-gram portion (± 

1.5 gram) and remove all damaged seed except heat-damaged and damaged-by-heat seeds. 

Compute the percentage for the damaged seed removed.

Mold Damaged
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 23

Pearling and Aspiration

Pour the remainder of the 30-gram portion 

into the barley pearler. Set the timer for a 

standardized pearl, and pearl the portion. 

Remove the hulls from the pearled portion, using 

the aspirator.

If the hulls are not all removed from the kernels, 

remove the remaining hulls by hand. 

Weigh the pearled portion. After pearling and 

aspiration, the pearled sample should weigh 

14 to 16 grams. If outside this range, reset the 

timer and pearl another portion.

Pearler

Aspirator

Heat Damage & Damaged-by-Heat

Separate the heat-damaged kernels and damaged-by-heat kernels from the sound kernels.

Record the percentage of damaged and heat-damaged sunflower seed on the certificate to 

the nearest tenth percent.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 24

Damaged-by-heat

Kernels and pieces of kernels with both sides as dark or darker than the kernel shown are 

damaged-by-heat.

Heat Damaged

Seeds damaged by heat usually have a dull dead appearance and are discolored brown or 

black. Kernels and pieces of kernels with both sides as dark or darker than the kernel shown 

are heat damaged, and are included in the total percentage for damaged sunflower seed.

Dehulled Seed

Dehulled Seed is sunflower seed that 

has the hull completely removed from the 

sunflower kernel. 

Determine dehulled seed after the removal 

of mechanically separated foreign material 

on a portion of 30 grams. 

Record the percent of dehulled seed on the 

certificate to the nearest tenth percent.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 25

Other Official Criteria

Admixture and oil content are “official 

criteria factors” and are determined only 

upon request. They do not affect the grade 

designation. 

Admixture consists of all material other 

than sunflower seed which can be removed 

from a test portion by hand sieving and 

handpicking. Consider empty hulls and 

parts of seed as sunflower seed. 

The major difference between admixture 

and foreign material is that hulls and pieces 

of hulls are not included in admixture. 

Consequently, the percent admixture will 

usually be lower than the percent foreign 

material. 

Admixture

The Oil Content of sunflower seed is determined using Nuclear Magnetic Resonance, or 

NMR technology.

NMR Oil Content Determination
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 26

Determine Admixture

Determine admixture on a portion of 60 grams before the removal of mechanically separated 

foreign material as follows: 

• Place the 60-gram portion on the upper edge of a 5/64 equilateral triangular hand sieve. 

• Hold the sieve at a 10 to 20-degree angle and gently work the material down over the 

sieve with a side-to-side motion. 

• After sieving, handpick all material other than sunflower seed from the material 

remaining on top of the hand sieve and add it to the material that passed through the 

hand sieve. Consider empty hulls and parts of seeds as sunflower seed 

Admixture consists of all material passing through the sieve, and all material other than 

sunflower seed, handpicked from the material remaining on top of the sieve. 

 Foreign Material Hulls and Partial Seeds

Record the percentage of admixture on the certificate to the nearest tenth percent.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 27

Grade Designations

After completing the analysis, assign a grade by comparing the results with the limits for each 

grade factor specified in the grade chart. 

The factor with the lowest grade designation determines the grade assigned to the sample. 

The Official U.S. Standards for Grain provide for an optional grade designation, commonly 

referred to as “or better.” 

Upon the request of an applicant, sunflower seed may be certified as U.S. No. 2 or better, 

U.S. No. 3 or better, etc. 

An “or better” grade designation cannot be applied to a U.S. No. 1 grade designation.
Grain Grading Primer Chapter 9: Sunflower Seed

October 2016

Page 9 - 28

Documenting the Grade

Use the following guide for documenting the assigned grade: 

• First write the letters “U.S.”, 

• Then, the abbreviation “No.” and the number of the grade or the words “Sample grade”, 

followed by the words “or better”, when applicable. 

• The words “sunflower seed”, 

• and finally, the special grade designation “Infested” when applicable

For Example: U.S. No. 2 sunflower seed, Infested
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 1

Chapter 10: Wheat

Grain Grading Primer

Chapter 10

Wheat
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 2

Contents

Chapter 10: Wheat

Definition of Wheat .................................................................................................................4

Wheat Classes ........................................................................................................................5

Grade Requirements ..............................................................................................................6

Sample Grade .........................................................................................................................6

Distinctly Low Quality ............................................................................................................8

Odor Determination ................................................................................................................9

Special Grades........................................................................................................................9

Processing an Original Sample...........................................................................................10

File Sample............................................................................................................................ 11

Moisture Determination .......................................................................................................12

U.S. Sample Grade Factors .................................................................................................13

Dockage ................................................................................................................................14

Determine Dockage ..............................................................................................................16

Test Weight ...........................................................................................................................17

Shrunken and Broken Kernels ...........................................................................................18
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 3

Dividing the Work Sample ...................................................................................................19

Class Determination .............................................................................................................20

Subclass ...............................................................................................................................22

Determine Damaged Kernels (Total) ...................................................................................23

Visual Reference Images (VRI) ...........................................................................................24

Insect Damaged Kernels (IDK) ............................................................................................30

Contrasting Classes (CCL) .................................................................................................31

Wheat of Other Classes (WOCL) .........................................................................................31

Determine Heat Damage (HT) ..............................................................................................32

Determine Foreign Material (FM) .........................................................................................32

Total Defects ........................................................................................................................32

Official Criteria .....................................................................................................................33

Work Record .........................................................................................................................33

Grade Designation ...............................................................................................................34

Optional Grade Designation ................................................................................................35

Certify the Result ..................................................................................................................35

Additional Information ........................................................................................................35
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 4

Grain that, before the removal of dockage, 

consists of 50 percent or more common 

wheat (Triticum aestivum L.), Club wheat 

(T. compactum Host.), and Durum 

wheat (T. durum Desf.) and not more 

than 10 percent of other grains for 

which standards have been 

established under the United 

States Grain Standards Act 

and that, after the removal 

of dockage, contains 

50 percent or more of 

whole kernels of one 

or more of these 

wheats.

Wheat is defined as:

Definition of Wheat
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 5

Wheat Classes

Wheat is divided into eight classes based on color and kernel and variety characteristics: 

Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, Soft White, Durum, 

Unclassed and Mixed Wheat. 

Hard Red Spring, Soft White and Durum Wheat are further divided into subclasses. 

Hard Red Spring Wheat includes all varieties of Hard Red Spring wheat. This class is 

divided into three subclasses: Dark Northern Spring, Northern Spring and Red Spring Wheat.

Hard Red Winter Wheat includes all varieties of Hard Red Winter wheat. There are no 

subclasses in this class.

Soft Red Winter Wheat includes all varieties of Soft Red Winter wheat. There are no 

subclasses in this class.

Hard White Wheat includes all hard endosperm white wheat varieties. There are no 

subclasses in this class.

Soft White Wheat includes all soft endosperm white wheat varieties. This class is divided 

into three subclasses: Soft White, White Club and Western White Wheat.

Durum Wheat includes all varieties of white (amber) Durum Wheat. This class is divided 

into three subclasses: Hard Amber Durum, Amber Durum and Durum Wheat.

Un-classed Wheat is any variety of wheat which is not classifiable under other criteria 

provided in the wheat standards. There are no subclasses in this class. This class includes 

any wheat which is other than red or white in color.

Mixed Wheat is any mixture of wheat which consists of less than 90 percent of one class 

and more than 10 percent of one other class, or a combination of classes which meet the 

definition of wheat. 
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 6

Grade Requirements

Each class and subclass is divided into five U.S. numerical grades and U.S. Sample Grade. 

Special grades are provided to emphasize special qualities or conditions affecting the value 

of wheat and are added to and made a part of the grade designation. Special grades do not 

affect the numerical or sample grade designation.

Grade Mixed wheat according to the U.S. numerical and U.S. Sample Grade requirements of 

the predominating class in the mixture. Disregard wheat of other classes.

GRADES AND GRADES REQUIREMENT CHART

WHEAT

Grade

Minimum Limits 

of - Maximum Limits of -

Test Weight per bushel

Damaged 

Kernels

Foreign 

material

(percent)

Shrunken 

and 

broken 

kernels

(percent)

Defects1

(percent)

Wheat of other 

classes2

Hard Red 

Spring 

Wheat 

or White 

Club 

Wheat

(pounds)

All other 

classes and 

subclasses

(pounds)

Heat 

damage

(part of 

total)

(percent)

Total

(percent)

Contrasting 

classes

(percent)

Total3

(percent)

U.S. No. 1 58.0 60.0 0.2 2.0 0.4 3.0 3.0 1.0 3.0

U.S. No. 2 57.0 58.0 0.2 4.0 0.7 5.0 5.0 2.0 5.0

U.S. No. 3 55.0 56.0 0.5 7.0 1.3 8.0 8.0 3.0 10.0

U.S. No. 4 53.0 54.0 1.0 10.0 3.0 12.0 12.0 10.0 10.0

U.S. No. 5 50.0 51.0 3.0 15.0 5.0 20.0 20.0 10.0 10.0

 1 Defects include damaged kernels (total), foreign material, and shrunken and broken kernels. The sum of these three 

 factors may not exceed the limit for defects for each numerical grade.

 2 Unclassed wheat of any grade may contain not more than 10.0 percent of wheat of other classes.

 3 Includes contrasting classes.

Sample Grade

U.S. Sample Grade is wheat that:

• Does not meet the requirements for grades U.S. No. 1 through 5;

• Contains 4 or more stones or any number of stones which have an aggregate weight in 

excess of 0.1 percent of the sample weight; 1 or more pieces of glass, 3 or more crotalaria 

seeds, 2 or more castor beans, 4 or more particles of an unknown foreign substance or 

a commonly recognized harmful or toxic foreign substance, 2 or more rodent pellets, bird 

droppings, or an equivalent quantity of other animal filth per 1,000 grams of wheat;

• Contains 5 or more animal filth, castor beans, crotalaria seeds, glass, stones, or unknown 

foreign substance(s) in any combination;
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 7

Has a musty, sour, or commercially objectionable foreign odor (except smut or garlic odor); 

• Is heating or otherwise of distinctly low quality;

• Contains more than 31 insect-damaged kernels in 100 grams.

Basis of Determination

The “Basis of Determination” establishes the rules for testing/analyzing all factors. Do not 

analyze any factor until the basis for making the determination is known.

BASIS OF DETERMINATION

Lot as a Whole

Factors Determined 

Before the Removal of 

Dockage

Factors Determined 

After the Removal of 

Dockage

Factors Determined 

After the Removal of 

Dockage and Shrunken 

and Broken Kernels

Distinctly low quality

Heating

Infested

Odor

Distinctly low quality

Garlicky

Heating

Infested

Kind of grain

Shrunken and broken 

Moisture

Odor

Odor (smut)

Other unusual conditions

U.S. Sample Grade 

factors

Ergot

Kind of grain

Odor

Protein

Shrunken and broken 

kernels

Smut

Stones

Test weight

Treated

Class

Contrasting classes

Damaged kernels (total)

Foreign material

Heat-damaged kernels

Subclass

Wheat of other classes

The determination of Distinctly Low Quality (DLQ) is made on the basis of the lot as a 

whole at the time of sampling when a condition exists that may or may not appear in the 

representative sample and/or the sample as a whole.

Each determination of rodent pellets, bird droppings, other animal filth, broken glass, castor 

beans, cockleburs, crotalaria seeds, dockage, garlic, live insect infestation, large stones, 

moisture, temperature, and unknown foreign substance(s), and a commonly recognized 

harmful or toxic substance(s) is made on the basis of the sample as a whole. When a 

condition exists that may not appear in the representative sample, the determination may 

be made on the basis of the lot as a whole at the time of sampling according to procedures 

prescribed in FGIS instructions.

Each determination of heat-damaged kernels, damaged kernels, foreign material, wheat of 

other classes, contrasting classes, and subclasses is made on the basis of the grain when 

free from dockage and shrunken and broken kernels. Other determinations not specifically 

provided for under the General Provisions are made on the basis of the grain when free from 

dockage, except the determination of odor is made on either the basis of the grain as a whole 

or the grain when free from dockage.
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 8

Distinctly Low Quality

Consider wheat DLQ when it is obviously of inferior quality and the existing grade factors or 

guidelines do not accurately reflect the inferior condition. 

Use all available information to determine whether the wheat is DLQ. This includes a general 

examination of the wheat during sampling and an analysis of the obtained sample. 

Wheat containing two or more stones, pieces of glass, pieces of concrete, or other pieces of 

wreckage or debris which are visible to the sampler but are too large to enter the sampling 

device is considered DLQ. 

Wheat that is obviously affected by other unusual conditions which adversely affect its quality 

but which cannot be properly graded by use of the grading factors specified or defined in the 

standards is also considered DLQ.

Wheat suspected of containing diatomaceous 

earth is considered distinctly low quality 

unless the applicant specifically requests an 

examination to verify the presence of 

diatomaceous earth. If the laboratory 

examination verifies that the wheat contains 

diatomaceous earth, then the wheat is not 

considered distinctly low quality due to 

diatomaceous earth. Refer to Program 

Directive 9180.49, for additional information 

regarding diatomaceous earth.

Heating

Wheat developing a high temperature from microbial activity is considered heating. As 

heating progresses wheat will develop a sour or musty odor. Care should be taken not to 

confuse wheat that is heating with wheat that is warm because of storage in bins, railcars, or 

other containers during hot weather. 
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 9

Odor Determination

Basis of Determination. Determine odor on evidence obtained at the time of sampling or 

on the sample either before or after the removal of dockage.

When grain has a “distinct” odor, it should be graded musty, sour, or commercially 

objectionable foreign odor.

The definition of “distinct”, when it pertains to odor, is not the intensity of the off-odor, but 

the presence of the off-odor. The consensus approach is not required if no odor, or a distinct 

odor, is present. 

Musty odors indicate the presence of fungal activity in the grain and are generally 

characterized as an earthy smell.

Sour odors indicate that the grain is fermenting due to microbial activity. Sour odors are 

often characterized as an acrid, boot pit or pigpen smell.

Commercially Objectionable Foreign Odor (COFO) are odors, except smut and garlic 

odors, foreign to grain that render it unfit for normal commercial usage. Sources of COFO 

include fumigants, oil products, smoke, fertilizer, weeds, decaying animal or plant matter, etc. 

Special Grades

Special grades are provided to emphasize special qualities or conditions affecting the value 

of wheat and are added to and made a part of the grade designation. There are six special 

grades in wheat: 

Ergoty wheat is wheat that contains more than 0.05 percent ergot. Ergot is a hard, reddishbrown or black grain-like mass of certain parasitic fungi that replaces the kernels of wheat. 

Ergot also functions as foreign material. 

Garlicky wheat is wheat that contains in a 1,000-gram portion more than two green garlic 

bulblets or an equivalent quantity of dry or partly dry bulblets. Three dry or partly dry garlic 

bulblets are equal to one green bulblet. Garlic bulblets also function as dockage or foreign 

material. 

Light Smutty wheat is wheat that has an unmistakable odor of smut or which contains, in a 

250-gram portion, smut balls, portions of smut balls, or spores of smut in excess of a quantity 

equal to 5 smut balls, but not in excess of a quantity equal to 30 smut balls of average size.

Smutty wheat is wheat that contains in a 250-gram portion, smut balls, portions of smut 

balls, or spores of smut in excess of a quantity equal to 30 smut balls of average size. 
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 10

Infested wheat is wheat that is infested with live weevils or other live insects injurious 

to stored grain. Do not examine the file sample if the work portion is insect free. If the 

work and file samples contain 2 or more live insects injurious to stored grain the sample is 

infested.

Treated wheat is wheat that has been scoured, limed, washed, sulfured, or treated in such 

a manner that the true quality is not reflected by either the numerical grades or the U.S. 

Sample grade designation alone. 

Processing an Original Sample

The Boerner Divider reduces the size of a grain sample while maintaining the representativeness

of the original sample. Use the Boerner divider, or a divider that gives equivalent results, 

when reducing a sample to the portion size required for a specific test/analysis.

When dividing the original sample the first pass through the divider will result in two equal 

portions. One of these portions should be set aside as a “file sample”. The other portion, a 

“work portion” will be reduced down to smaller quantities or use in determining required tests 

and analysis specific to the type of grain being graded.

Original Sample

File Work
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 11

Operating Procedures 

• Check the divider for condition and cleanliness

• Close the hopper valve

• Place empty collection pans under the discharge spouts

• Pour the sample into the hopper

• Open the valve quickly. For large samples, feed more grain into the hopper during the 

dividing process.

File Sample

A “file sample” is a representative sample or representative portion of a sample that is 

retained for a specified period of time for reference or review purposes. File samples 

should be of sufficient size to accommodate subsequent examinations or analysis. The file 

sample shall be an unworked portion (if available) of the representative sample used for 

the inspection. The worked portion may be retained as the final file only when insufficient 

sample is available for an unworked file sample. 

Keep all samples in sealed moisture proof containers if they cannot be tested within 

approximately 15 minutes. Do not use paper bags, fiber cartons, or similar containers that 

allow moisture losses. Use metal cans, plastic containers, and plastic bags to preserve the 

sample integrity. Do not file samples with paper identification inserted in the grain. Paper 

absorbs moisture and lowers the moisture of the grain.
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 12

Moisture Determination

Water content in grain as determined by an approved device according to procedures 

prescribed in FGIS instructions.

Basis of Determination. Determine moisture before the removal of dockage on a portion of 

approximately 650 grams.

The user interfaces are slightly different for the two UGMA compatible moisture meters. Use 

the keypad to choose the type of grain to analyze. 

Fill the hopper and press the load key to start the test cycle. After the moisture analysis 

is complete observe the result on the display, record it and reclaim the sample from the 

discharge tray. 

For additional information, refer to the GIPSA Moisture Handbook. 

 GAC2500-UGMA

Perten AM 5200-A
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 13

U.S. Sample Grade Factors

Basis of Determination. Determine U.S. Sample Grade criteria, except stones, before the 

removal of dockage based on a work portion of 1,000-1,050 grams. 

Examine the sample for Sample Grade factors such as animal filth, glass, toxic seeds, and 

unknown foreign substances. 

Consider identifiable pieces of grain, processed grain products such as soybean meal, 

sorghum grits, corn meal, bulgur, etc., or feed pellets in grain as foreign material. 

Unidentifiable materials or material unrelated to grain shall function as "unknown foreign 

substance". 

Kernels of wheat discolored by treatment with a fungicide or similar substance such as “pink 

wheat” are considered as being discolored by an unknown foreign substance. 

 Toxic Seeds Animal Filth

 (Crotalaria)
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 14

Dockage 

All matter other than wheat that can be removed from the original sample (1,000 to 

1,050 grams) by use of an approved device according to procedures prescribed in FGIS 

instructions. Also, underdeveloped, shriveled, and small pieces of wheat kernels removed in 

properly separating the material other than wheat and that cannot be recovered by properly 

rescreening or recleaning.

The Carter Dockage Tester uses aspiration or air and a combination of riddles and sieves to 

prepare samples for grading by removing the readily separable foreign matter. 

Generally, foreign material removed consists of all matter lighter, larger, or smaller than grain.
Grain Grading Primer Chapter 10: Wheat 

October 2016

Page 10 - 15

Carter Dockage Tester

AIR COLLECTION PAN AIR (4)

HOPPER

RIDDLE (#2 or #25 Durum)

TOP SIEVE (no sieve)

RIDDLE

COLLECTION PAN

BOTTOM COLLETION PAN

TOP SIEVE

COLLECTION PAN

MIDDLE SIEVE

COLLECTION PAN

BOTTOM SIEVE

COLLECTION PAN

FEED CONTROL (6)

MIDDLE SIEVE (#2)

BOTTOM SIEVE (#2)
Grain Grading Primer Chapter 10: Wheat 

October 2016

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Dockage Tester Operating Procedures

• Air Control: 4

• Feed Control: 6

• Riddle Carriage: #2 riddle for wheat other than Durum or #25 riddle for Durum

• No sieve in the top sieve carriage

• Middle and Bottom Sieve Carriages: #2 sieves

• Check the air collection pan to see if it is empty and place the collection pans in the 

prescribed locations. 

• Start the dockage tester and pour the wheat sample in the feed hopper. When all of the 

grain has cleared the hopper, riddle, and sieves, turn the tester off. Collect all material 

separated by the riddle, aspirator, and sieves. 

Determine Dockage

Aspirated material in the air collection pan is dockage.

Material over the riddle, except for threshed and sprouted kernels is dockage. Threshed 

kernels do not have more than one glume attached. Place threshed and sprouted kernels in 

the cleaned wheat.

Material passing over the bottom sieve is dockage if it contains less than 50 percent (by 

weight) of wheat kernels. If 50 percent or more of wheat kernels pass over the bottom sieve, 

return the material to the cleaned wheat.

Material in the bottom collection pan is dockage.

Record dockage to the nearest tenth percent on the work record and the certificate. If 

dockage is less than one-tenth percent, report as “Dockage 0.0%.”
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General Operating Procedures

Test Weight

Test weight per bushel is the weight per Winchester bushel (2,150.42 cubic inches) as 

determined using an approved device. The determination for test weight is made on a 

portion of sufficient quantity to overflow the kettle. 

1. Level and balance the test

weight per bushel apparatus.

2. Close the hopper valve.

3. Pour the work sample into the 

hopper.

4. Center the hopper over the 

kettle.

5. Fill the kettle by opening the 

hopper valve quickly.

6. Move the hopper all the way 

to the left before proceeding. 

Do not jar the apparatus. 

Jarring could cause 

inaccurate results.

7. Using a standard stroker, stroke the 

kettle by holding the stroker in both 

hands with the flat sides in a vertical 

position. Level the grain in the kettle 

by making three full length, zigzag 

motions with the stroker.

8. Place an empty sample pan or the test weight kettle on the scale and zero the scale. 

Pour the sample from the kettle into the sample pan or place the filled kettle onto the 

scale as appropriate. Read the result from the test weight mode selected.

9. Record the test weight per bushel on the work record. 
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Shrunken and Broken Kernels 

Shrunken and broken kernels consist of all matter that passes through a 0.064 x 3/8 oblonghole sieve after sieving. Mechanical sieving is preferred over the hand-sieving method 

because the results are more uniform and accurate in counting the number of strokes. Cut 

out a 250 gram portion for shrunken & broken kernels using the Boerner Divider.

Mechanical Sieving Procedures

1. Make sure mechanical

shaker is level.

2. Mount the 0.064 x 3/8-inch 

oblong-hole sieve and 

the bottom pan on the 

mechanical sieve shaker 

with the sieve perforations 

parallel to the direction of 

movement. 

3. Set the stroke counter for 

30 strokes. 

4. Gently pour the 250-gram 

portion of Wheat in the 

center of the sieve. Turn 

the machine on. After the 

required number of strokes 

has been completed, the 

machine will automatically 

stop. Carefully remove the

sieve and bottom pan. 

All material passing through the sieve is considered shrunken and broken kernels. Return 

the material that is lodged in the perforations to the wheat which remained on top of the 

sieve. To remove the lodged material from the perforations, rub the sieve bottom gently. 

NOTE: Tapping will warp the sieve and lead to inaccurate results in future determinations.
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October 2016

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If an approved mechanical shaker is unavailable, inspectors may handsieve the sample. 

When handsieving, place the 250-gram portion in the center of the sieve, hold the sieve level 

in both hands with elbows close to the sides, in a steady motion, move the sieve from left to 

right approximately 10 inches and then return from right to left. Repeat this motion 30 times.

Dividing the Work Sample

After all tests required to be performed prior to the removal of dockage have been made, the 

percentage of dockage has been determined and the sample has been test weighed and 

examined for certain sample grade and special grade factors, divide the work sample into 

fractional portions for other determinations required after the removal of dockage. 

APPROXIMATE ANALYTICAL PORTION SIZES

Factors Grams

Ergot 

Shrunken and broken kernels 

Smut 

Class 

Contrasting classes 

Damaged kernels (total)

Foreign material 

Heat-damaged kernels 

Insect-damaged kernels 

Insect-damaged kernels Stage 1 

Insect-damaged kernels Stage 2 

Insect-damaged kernels Stage 3 

Subclass 

Wheat of other classes

1,000

250

250

15

15

15

50

50

100

15

15

100 – (Stage 1 + Stage 2)

15

15
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October 2016

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Class Determination

Determine class on a dockage-free and shrunken and broken-free portion of 15 grams. Use 

kernel and varietal characteristics when making this determination.

Durum wheat is divided into three subclasses: 

• Hard Amber Durum Wheat is durum wheat with 75 percent or more of hard and 

vitreous kernels of amber color. 

• Amber Durum Wheat is durum wheat with 60 percent or more but less than 75 percent 

of hard and vitreous kernels of amber color. 

• Durum Wheat is durum wheat with less than 60 percent of hard and vitreous kernels of 

amber color.

Hard Red Spring wheat is divided into three subclasses: 

• Dark Northern Spring Wheat is Hard Red Spring wheat with 75 percent or more of 

dark, hard, and vitreous kernels;

• Northern Spring Wheat is Hard Red Spring wheat with 25 percent or more but less 

than 75 percent of dark, hard and vitreous kernels;

• Red Spring Wheat is Hard Red Spring wheat with less than 25 percent of dark, hard, 

and vitreous kernels.

Hard Red Winter Wheat. All varieties of Hard Winter wheat. There are no subclasses in this 

class.

Soft Red Winter Wheat. All varieties of Soft Red Winter wheat. There are no subclasses in 

this class.

Hard White Wheat. All hard endosperm white wheat varieties. There are no subclasses in 

this class.

Soft White Wheat is divided into the following three subclasses: 

• Soft White Wheat which is soft endosperm white wheat varieties that contain not more 

than 10 percent of white club wheat. 

• White Club Wheat which is soft endosperm white club wheat containing not more than 

10 percent of other soft white wheats. 

• Western White Wheat which is soft white wheat containing more than 10 percent of 

white club wheat and more than 10 percent of other soft white wheats.

Unclassed Wheat. Any variety of wheat which is not classifiable under other criteria 

provided in the wheat standards. There are no subclasses in this class. This class includes 

any wheat which is other than red or white in color.

Mixed Wheat. Any mixture of wheat which consists of less than 90 percent of one class 

and more than 10 percent of one other class, or a combination of classes which meet the 

definition of wheat.
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Kernel Characteristics. Kernel characteristics include the color, shape, and length of the 

kernel and the shape of the germ, crease, and brush. Inspection personnel should be familiar 

with kernel characteristics of all classes of wheat handled in their market.

Varietal Characteristics. Some varieties possess characteristics of two or more classes. 

Knowledge of distinct varietal characteristics is necessary in making class determinations. 

Inspection personnel should be familiar with the characteristics of all varieties of wheat 

handled in their market.

Classification of Recognized Varieties. Hard red varieties of wheat grown during the winter 

season in Arizona, California, Nevada, New Mexico, and Texas and marketed in these States 

are classed as Hard Red Winter Wheat.

Distinguishing Between White and Red Kernels in Hard or Soft Wheat. To assist in the 

detection of white and red wheat kernels in samples of Hard or Soft wheat, official personnel 

may use the commercially available sodium-hydroxide test kit, or the potassium-hydroxide 

test method developed by FGIS. 

The tests can serve as a useful tool when samples challenge the normal visual inspection 

method. Due to the resulting similarity in kernel color after the process is completed and 

the affect these chemical processes may have on kernel morphology, it is necessary 

to determine whether a sample contains different classes of white or red wheat prior to 

performing the test.

Sodium-Hydroxide Test. The sodium-hydroxide turns red wheat a dark red in color, and 

turns white wheat a straw yellow in color. When using the commercially available test kit, 

follow the procedures as provided by the test kit manufacturer.

Potassium-Hydroxide Test. Use the following procedure: 

1. Place approximately 15 grams of wheat in a mixing jar.

2. Add 10 grams of potassium-hydroxide (KOH) pellets.

3. Add 40 ml of bleach.

4. Set stirring head on jar, place jar on mixer, and mix for 1 to 11⁄2 minutes.

5. Pour the wheat from the mixing jar into a tea strainer and rinse with warm tap water to 

remove the sodium-hydroxide/bleach solution.

6. After rinsing, lightly tap the tea strainer against the edge of the sink to remove the 

excess water. Gently press the bottom of the tea strainer on a dry paper towel to 

remove any additional water.

7. Place the wheat on a dryer sieve and dry until the kernels are not tacky when picked up 

with a pair of tweezers.
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October 2016

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8. Remove the wheat from the drying sieve and observe the color. 

 White wheat turns a light straw or amber color. Red wheat turns a 

 dark brownish /red color.

Caution: Too much potassium-hydroxide (step 2) or over mixing (step 4) may remove the 

bran in red wheat.

Subclass 

Subclass is determined on Hard Red Spring wheat, Durum wheat and Soft White wheat. 

When an analysis is necessary, determine subclass on a dockage-free and shrunken and 

broken-free portion of 15 grams. 

Record the subclass and percentage of Dark Hard And Vitreous kernels (DHV), Hard & 

Vitreous kernels of Amber Color (HVAC), and White Club wheat kernels on the work record to 

the nearest tenth percent and on the certificate to nearest whole percent.

Hard Red Spring Wheat 

• Consider hard red spring kernels which are bleached but are hard, or hard and vitreous as 

DHV. 

• Consider hard red spring kernels which have cracks or checks that cause a cloudy or 

shadowy spot on the kernel but are otherwise dark, hard, and vitreous as DHV. 

• Consider kernels of Soft Red Winter wheat and Hard Red Winter wheat as DHV when they 

are dark, hard, and vitreous in texture. 

• Kernels which are yellow or contain a mottled spot, regardless of size, distinctly green 

immature kernels, severely affected by scab, sprouted, foreign material, and kernels 

of Hard White wheat, Unclassed wheat, Soft White wheat, and Durum wheat are not 

considered DHV.

DHV Wheat Kernels (cross-sectioned)
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October 2016

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Durum Wheat

• Consider Durum kernels which are bleached but which are hard and vitreous as HVAC. 

• Consider Durum kernels which have cracks or checks that cause a cloudy or shadowy 

spot on the kernel but which are otherwise hard and vitreous as HVAC. 

• Kernels with mottled or chalky spots, regardless of size, are not considered HVAC. 

• Distinctly green immature kernels, kernels affected by scab, sprouted kernels, foreign 

material, and all other classes of wheat are not considered HVAC.

•

HVAC Wheat Kernels (cross-sectioned)

Soft White Wheat

• The percentage of White Club wheat is applicable to all subclasses of Soft White wheat.

Determine Damaged Kernels (Total)

Damaged Kernels Total (DKT) is kernels, pieces of wheat kernels and other grains that are 

badly ground-damaged, badly weather-damaged, diseased, frost-damaged, germ-damaged, 

heat-damaged, insect-bored, mold-damaged, sprout-damaged, or otherwise materially 

damaged. 

Determine damaged kernels on a dockage-free and shrunken and broken-free portion of 15 

grams.

In general, a kernel of wheat and/or kernels of other grains are considered damaged for 

inspection and grading purposes only when the damage is distinctly apparent and of such 

character as to be recognized as damaged for commercial purposes. 
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October 2016

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Visual Reference Images (VRI) 

Because of the subjectivity involved in determining damage and other criteria, it is critical that 

visual references are available to ensure that interpretations are uniformly and consistently 

applied throughout the national system. 

Visual Reference Images provide a basis for communicating the minimum “line” for various 

types of damage and other visually determined criteria.

For the complete inventory of GIPSA’s VRI visit GIPSA’s website.

BLACK TIP DAMAGE (Fungus)

Kernels affected by black tip fungus to the extent that the discoloration or fungus growth 

extends beyond the germ and continues around at least one check and into the crease are 

considered damaged. All conditions MUST be met to be considered damage. 
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SCAB DAMAGE

Fusarium head blight or head scab is caused by the fungus Fusarium graminearum. Kernels 

with a dull, lifeless and chalky appearance resulting from this disease are considered 

damaged. The germ and crease may also contain a visible white or pinkish mold. 

FROST DAMAGE (Blistered)

Kernels that have blisters due to frost are considered damaged. The Illustration shows 

kernels with distinct frost blisters extending around the back of the kernel and into the crease. 

The blister and wrinkle effect must be distinct.

FROST DAMAGE (Candied)

Kernels that have a distinctly wax-like or candied appearance are considered damaged. 

Frost-damaged (candied) kernels can be greenish, greenish yellow, brownish, or blackish in 

color. They frequently have dark stripes showing through the sides of the kernels.
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FROST DAMAGE (Discolored Black/Brown)

Kernels which are completely discolored black or brown and/or have a bleached or blistered 

appearance with dark lines showing through both sides are considered damaged. 

FROST DAMAGE (Flaked)

Kernels that have a slightly flaked-off bran coat due to frost are considered damaged. The 

flaked area singularly or in combination, must be equal to or greater than depicted by the 

kernel shown. Evidence of frost must be present on suspect kernels. Do not confuse flakedby-frost with kernels which have had the bran coat rubbed off because of handling. 

GERM DAMAGE

Kernels and pieces of wheat which have discolored germs that are as dark or darker than 

shown shall be damage. Scrape the germ carefully to avoid scraping too deeply and 

destroying the evidence of damage. Discolored germs that do not meet the minimum 

coverage requirement may be considered damage provided the degree of discoloration is 

greater than shown and the overall “prorated” appearance meets the minimum coverage and 

intensity level depicted. 
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GERM DAMAGE (Bleach Method) 

Kernels and pieces of wheat which, after bleaching, have discolored germs that are as 

dark or darker than shown are damaged. Discolored germs that do not meet the minimum 

coverage requirement may be considered damage provided the degree of discoloration is 

greater than shown and the overall “prorated” appearance meets the minimum coverage and 

intensity level depicted. For example, when the degree of discoloration is twice that shown, 

only half of the germ area needs to be discolored.

MOLD DAMAGE

Kernels containing any amount of mold in the germ or an applicable amount in the crease 

shall be damage. Mold occurs in many colors. The bran coat covering the germ should be 

removed carefully as scraping the bran coat too deep could remove the mold.

GREEN DAMAGE (Immature)

Kernels which are green (immature) in color are considered damaged. The green color must 

meet the minimum intensity shown on both sides of the kernel. Also there should be no 

yellow cast showing through the green. Do not confuse green damaged kernels with candied 

kernels.
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HEAT DAMAGE (Durum)

Kernels and pieces of kernels of wheat that are materially discolored to the extent shown are 

considered damaged. Cross-sectioning of whole kernels may be necessary to confirm that 

the face of both halves are as dark as shown. A kernel with a combination of vitreous and 

creamy discoloration meeting the VRI shall be heat damage. 

HEAT DAMAGE (Other Than Durum)

Kernels and pieces of kernels of wheat that are materially discolored to the extent shown are 

considered damaged. Cross-sectioning of whole kernels may be necessary to confirm that 

the face of both halves are as dark as shown. A kernel with a combination of vitreous and 

creamy discoloration meeting the VRI shall be heat damage.

SPROUT DAMAGE

Kernels with the germ end broken open from germination exhibiting sprout or from which 

the sprouts have been broken off are considered damaged. The sprout is broken off leaving 

part of the germ cover over the socket area. Sprout sockets typically have bran around the 

perimeter of the germ that resembles a “horse collar”
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OTHER DAMAGE (Mold)

Kernels which are broken, cracked, or insect chewed and contain distinct mold on the 

exposed endosperm, regardless of size, are damaged. 

WEEVIL OR INSECT-BORED 

Kernels and pieces of wheat kernels and other grains which have been bored or tunneled 

by insects are considered damage. Pin holes in the germ area must be examined further to 

determine if penetration extends into the endosperm.

INSECT CHEWED WHEAT (Not Damaged)

Kernels which are slightly chewed by insects but are otherwise sound are not considered 

damaged. Kernels in which the germ has been chewed are sound unless otherwise 

damaged. 
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Insect Damaged Kernels (IDK)

To coincide with the Food and Drug Administration's defect action levels, the U.S. Standards 

for Wheat consider wheat containing 32 or more insect-damaged kernels per 100 grams to 

be U.S. Sample grade. Insect-damaged kernels are kernels bored or tunneled by insects. 

Determine insect-damaged kernels or IDK 

on a representative portion of dockage-free 

and shrunken and broken-free wheat. A 

three-stage inspection process has been 

developed to eliminate the need to always 

examine 100 grams. This process involves 

examining up to a total of 100 grams and 

applying tolerances calculated to duplicate, 

as near as possible, the 32 insect-damaged 

kernels per 100 grams limit.

IDK Stage 1: Examine the damaged kernel portion for insect-damaged kernels and apply 

the result to the following guidelines: For 0 - 1 insect-damaged kernels the lot is not sample 

grade. For 9 or more insect-damaged kernels the lot is sample grade. For 2 - 8 insectdamaged kernels go to Stage 2. 

IDK Stage 2: Examine a second portion of approximately 15 grams, for example the 

classing portion, for insect-damaged kernels and apply the result to the following guidelines: 

For 0 - 1 insect-damaged kernels the lot is not sample grade. For 9 or more insect-damaged 

kernels the lot is sample grade. For 2 - 8 insect-damaged kernels go to Stage 3.

IDK Stage 3: Examine a third portion for insect-damaged kernels. Determine this portion 

size by subtracting from 100 grams the combined weight of the work portions used in Stage 

1 and Stage 2. Add together the total number of insect-damaged kernels found in all three 

stages and apply the total to the following guidelines: For 31 or less insect-damaged kernels 

the lot is not sample grade. For 32 or more the lot is sample grade.
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Contrasting Classes (CCL) 

Contrasting classes are defined as: (1) Durum wheat, Soft White wheat, and Unclassed 

wheat in the classes Hard Red Spring wheat and Hard Red Winter wheat; (2) Hard Red 

Spring wheat, Hard Red Winter wheat, Hard White wheat, Soft Red Winter wheat, Soft White 

wheat, and Unclassed wheat in the class Durum wheat; (3) Durum wheat and unclassed 

wheat in the class Soft Red Winter wheat; (4) Durum wheat, Soft Red Winter wheat, and 

Unclassed wheat in the class Hard White wheat; and (5) Durum wheat, Hard Red Spring 

wheat, Hard Red Winter wheat, Soft Red Winter wheat, and Unclassed wheat in the class 

Soft White wheat.

Determine contrasting classes on a dockage-free and shrunken and broken-free portion of 15 

grams. Use kernel and varietal characteristics when making this determination.

CONTRASTING CLASSES OF WHEAT

Class Contrasting Class

Hard Red Winter and Hard Red Spring wheat Durum, Soft White, and Unclassed wheat

Durum wheat Hard Red Spring, Hard Red Winter, Soft Red Winter, 

Hard White, Soft White, and Unclassed wheat

Soft Red Winter wheat Durum and Unclassed wheat

Hard White wheat Durum, Soft Red Winter and Unclassed wheat

Soft White wheat Durum, Hard Red Winter, Hard Red Spring, Soft 

Red Winter, and Unclassed wheat

Wheat of Other Classes (WOCL)

Wheat of other classes is the total of all classes of wheat other than the predominating class 

and which, combined with the predominating class, meets the requirements for any one of 

the classes except Mixed wheat. 

Because all other classes of wheat are considered contrasting classes in durum wheat, the 

factor wheat of other classes is not applicable to durum.

Determine wheat of other classes on a dockage-free and shrunken and broken-free portion 

of 15 grams. Use kernel and varietal characteristics when making this determination.

Record the percent of wheat of other classes on the certificate to the nearest tenth percent 

unless that percentage falls within 10.1 to 10.4 percent. When this occurs, to be consistent 

with the reporting requirements for Mixed wheat, certify wheat of other classes as 10.0 

percent. 
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Determine Heat Damage (HT)

Kernels, pieces of wheat kernels, and other grains that are materially discolored and 

damaged by microbial activity that remain in the sample after the removal of dockage and 

shrunken and broken kernels are considered heat damaged. Determine heat-damaged 

kernels on a dockage-free and shrunken and broken-free portion of 50 grams. Record the 

percent of heat-damaged kernels on the certificate to the nearest tenth percent. 

Determine Foreign Material (FM)

Foreign material or FM consists of all matter other than wheat that remains in the sample 

after the removal of dockage and shrunken and broken kernels. Determine foreign material 

on a dockage-free and shrunken and broken-free portion of 50 grams. 

Other grains including oat groats, hull-less oats, glumes on threshed or unthreshed kernels 

and all matter other than wheat are considered foreign material and removed from the 

portion. Remove the glumes from the kernels of wheat and add to the foreign material. 

Record the percent of FM on the certificate to the nearest tenth percent.

Total Defects 

Total Defects is the sum of damaged kernels, foreign material, and shrunken and broken 

kernels. The sum of these three factors may not exceed the limit for the factor defects for 

each numerical grade. A percentage for defects cannot be shown when only one or two of 

the factors defined as defects have been determined. 

When one or two factors are determined and their sum would change the numerical grade, or 

come close to changing the grade, determine the other factor and record the percentage of 

defects. Record the percent of defects on the certificate to the nearest tenth percent. When 

the percentages for damaged kernels, shrunken and broken kernels, and foreign material 

are added together and the total exceeds 100 percent, adjust the percentage of defects by 

adjusting damaged kernels total.
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Official Criteria 

Factors, such as protein, mycotoxins, falling number and single kernel hardness are 

considered as official criteria that are determined upon request and do not affect the grade.

 Mycotoxin Testing Protein Analysis

Work Record

FGIS personnel use Forms FGIS920, “Grain Sample Ticket,” (example 

below) FGIS-918, “Sample Pan Ticket,” 

FGIS-919, “Sampling Ticket,” or FGIS921, “Inspection Log,” to record all 

sampling and inspection information.
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Grade Designation

After completing the analysis, compare the results with the limits for each grade factor 

specified the Grades and Grades Requirements table. The factor with the lowest grade 

designation determines the grade assigned to the sample. 
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Optional Grade Designation

The Official U.S. Standards for Grain provide for an optional grade designation, commonly 

referred to as “or better”. Upon the request of an applicant wheat may be certified as U.S. 

No. 2 or better, U.S. No. 3 or better, etc. An “or better” grade designation cannot be applied 

to a U.S. No. 1 grade designation.

Certify the Result

Use the following guidelines when documenting the assigned grade. First write the letters 

“U.S.”, then the abbreviation “No.” and the number of the grade or the words “Sample grade”, 

the words “or better” when applicable, the subclass or, in the case of Hard Red Winter wheat, 

Hard White wheat, Mixed wheat, Soft Red Winter wheat and Unclassed wheat, the class.

Next, indicate the applicable special grade in alphabetical order except for treated wheat. 

The grade designation for treated wheat includes, following the class or subclass and any 

special grade designations, the word “treated” followed by a statement indicating the kind of 

treatment, for example, scoured, limed, washed, sulfured, etc. and finally the word “dockage” 

and the percentage thereof. 

Additional Information 

Include the following in the “Remarks” section of the certificate: 

For Western White wheat, the name and percentage of White Club wheat. 

For Unclassed wheat, the color or other characteristics which describe the wheat, together 

with the percentage thereof.

For Mixed wheat, the name and percentage of the classes that comprise the mixture in the 

order of predominance. 

When applicable, the percentage of protein, falling number value, parts per million of 

Deoxynivalenol and/or the hardness score.