United States Department of Agriculture

Agricultural Marketing Service

Federal Grain Inspection Service

Directive 9180.64 March 14, 2022

Distribution: FGIS, OSP, Industry Originating Office: FMD PPMAB

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INSPECTION OF POPCORN

Contents

DIRECTIVE TITLE �����������������������������������������������������������������������������������������������������������������1

1. PURPOSE����������������������������������������������������������������������������������������������������������������������������

2. REPLACEMENT HIGHLIGHTS��������������������������������������������������������������������������������������������

3. DEFINITION OF POPCORN������������������������������������������������������������������������������������������������

4. GENERAL INFORMATION���������������������������������������������������������������������������������������������������

5. PERCENTAGES�������������������������������������������������������������������������������������������������������������������

6. BASIS OF DETERMINATION ����������������������������������������������������������������������������������������������

7. INSPECTION FACTORS������������������������������������������������������������������������������������������������������

8. TYPE OF SERVICES���������������������������������������������������������������������������������������������������������1

9. LEVEL OF SERVICE����������������������������������������������������������������������������������������������������������1

a. Original service is the initial inspection of a lot or a submitted sample. �����������������������������

10. TESTING SERVICE ���������������������������������������������������������������������������������������������������������1

11. CERTIFICATION���������������������������������������������������������������������������������������������������������������1

12. QUESTIONS ��������������������������������������������������������������������������������������������������������������������1
FGIS Directive 9180.64 March 14, 2022

Page 2

1. PURPOSE

This directive establishes uniform procedures for the factor analysis of popcorn. This

service is provided under the authority of the Agricultural Marketing Act of 1946 (AMA), 

as amended

2. REPLACEMENT HIGHLIGHTS

This directive is revised to specify that any moisture meter listed as approved in 

the Moisture Handbook can be used to determine moisture content. This directive

supersedes FGIS Directive 9180.64, dated 5/01/1

3. DEFINITION OF POPCORN

a. Popcorn (Zea Mays Everta) as used in this directive is commodity that, before the

removal of FM, consists of 80 percent or more of whole or broken popcorn kernels

b. Whole kernels are kernels with three-fourths or more of the kernel presen

c. Normally, a visual appraisal of the sample is sufficient to determine if it meets the 

definition of popcorn. However, if an analysis is necessary, make the determination 

on a portion of 125 grams before the removal of FM

4. GENERAL INFORMATION

There are no classes, subclasses, or grades for popcorn. The inspection of popcorn is

on a factor only basis. The factors analyzed are: kind of grain, insects, heating, odor,

animal filth, moisture, bird dropping, broken glass, castor beans, cockleburs, color, 

crotalaria seeds, stones, unknown foreign substances, heat-damaged kernels, damaged 

kernels, foreign material, aflatoxin, and popping ratio.

5. PERCENTAGES

Except for kind of commodity, state all percentages in whole and tenth percent. State 

the kind of grain to the nearest whole percent
FGIS Directive 9180.64 March 14, 2022

Page 3

6. BASIS OF DETERMINATION

Table 1

Basis of Determination

Factors Determined on the 

Basis of Lot as a Whole

Factors Determined Before 

the Removal of FM

Factors Determined After the 

Removal of FM

Heating

Odor

Heating

Insects

Kind of grain

Moisture

Odor

Stones

Unknown foreign substances

Aflatoxin

Foreign material

Damaged kernels

Heat-damaged kernels

Odor

Popping ratio

Color

7. INSPECTION FACTORS

a. Factors Determined Before the Removal of F

(1) Insects

Insects refer to popcorn that has live weevils or other live insects injurious to 

stored grain, according to procedures prescribed in Federal Grain Inspection 

Service (FGIS) instructions

(a) Examination Procedure Order. Examine the work sample and the file for 

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

(b) Injurious Insect References. Live weevils will include rice weevils,

granary weevils, and lesser grain borers. Other live insects injurious to

stored grain will include grain beetles, grain moths, mealworms, vetch 

bruchids, and larvae

(c) Basis of Determination. Determine insects on evidence obtained at the

time of sampling on the lot as a whole or the sample before the removal 

of FM (approximately 1,000 grams).

(d) Certification. If the lot is found to contain insects, record the word

“Insects” on the certificate and pan ticket showing the number and kind 

of live weevils and other live insects injurious or damaging to stored 

grain
FGIS Directive 9180.64 March 14, 2022

Page 4

(2) Heating

(a) Definition. A high temperature from excessive respiration is considered 

heating. Heating popcorn in its final stages usually produces a sour or 

musty odor

Do not confuse a lot that is heating with a lot that is warm and moist 

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

weather

(b) Basis of Determination. Determine heating on evidence obtained at the

time of sampling on the lot as a whole or the sample before the removal 

of FM

(c) Certification. When heating is detected, show the word “Heating” on the

pan ticket and certificate.

(3) Animal Filth, Glass, and Unknown Foreign Substance

(a) Basis of Determination. Determine animal filth, glass, and unknown 

foreign substances on the basis of the sample as a whole before the 

removal of FM (approximately 1,000 grams).

(b) Notification. Immediately report any animal filth found in the sample to 

the Food and Drug Administration District office nearest to the location of 

the Popcorn lot

(c) Certification. Record the number of pieces of animal filth, glass, and 

unknown foreign substances on the pan ticket and the certificate.

(4) Moisture

(a) Definition. Moisture is the water content in popcorn as determined b

approved moisture instruments listed in the Moisture Handbook using the 

approved calibration (see FGIS Directive 9180.61

(b) Basis of Determination. Determine moisture on a portion of approximatel

650 grams before the removal of FM

(c) Certification. Record the percentage of moisture on the pan ticket and

the certificate to the nearest tenth percent.
FGIS Directive 9180.64 March 14, 2022

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(5) Odor

(a) Basis of Determination. Determine odor on evidence obtained at the

time of sampling, either before or after the removal of FM. Odor detected

at the time of sampling must be recorded on the pan ticket. However, the

final determination for odor must be performed in the laboratory.

Table No. 2 - Odor Classification Examples

Sour Musty Commercially Objectionable

Foreign Odors

Boot

Fermenting

Insect (acrid)

Pigpen

Ground

Insect

Moldy

Animal hides

Decaying animal and vegetable matter

Fertilizer

Fumigant

Insecticide

Oil products

Skunk

Smoke

Strong weed

(b) Commercially Objectionable Foreign Odors. Commercially Objectionable

Foreign Odors (COFO) are odors foreign to popcorn that render it unfit 

for normal commercial usage

(c) Odor Dissipation. Fumigant or insecticide odors are considered COFO

if they linger and do not dissipate. When a sample of popcorn contains a

fumigant or insecticide odor that prevents a determination as to whether 

any other odor(s) exists, apply the following guidelines:

1 Original Inspection. Allow the work portion to aerate in an open

container for 4 hours, or less, if the odor dissipates in less time

2 Appeal Inspections, and Board Appeal Inspections. Allow unworke

file samples and new samples to aerate in an open container for a 

period not to exceed 4 hours. Do not aerate file samples (unworked 

files) which were previously aerated and retained as the final file.

(d) Odor Does Not Dissipate. Consider the sample as having a COFO if the

fumigant or insecticide odor persists based on the above criteria

(e) Certification. If present, record the words “Musty,” “Sour,” or

“Commercially Objectionable Foreign Odor” on the pan ticket and the 

certificate.
FGIS Directive 9180.64 March 14, 2022

Page 6

(6) Foreign Material

All matter other than popcorn

(a) Basis of Determination. Determine the factor Foreign Material (FM) on a

portion of approximately 1,000 grams.

The approved methods for determining the factor FM are the methods 

described in this section. The procedure is performed in two steps: The

sieve sizes are used as an aid in the determination of FM

1 A mechanical separation of FM is made using a Carter Dockage 

Tester to remove the larger and finer particulate matter from the 

sample

2 The mechanically cleaned sample is then handpicked to remove 

any remaining similarly sized FM from the sample

To avoid repeating operations, check the material found in the FM 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
FGIS Directive 9180.64 March 14, 2022

Page 7

PROCEDURE FOR DETERMINING FM

STEP 1. Carter Dockage 

 Tester

a. Set the air control to 1 an

the feed control to 6

b. Insert the No. 3 (12/6

sieve in the top sieve 

carriage

c. Insert a 5/64 or 6/64 roundhole sieve in the botto

sieve carriage

d. Run 1,000 – 1,050 gram

through the dockage tester

STEP 2. Handpick (foreign 

 material)

a. Remove all matter oth

than popcorn from the 

mechanically cleaned 

portion

b. Combine the mechanicall

separated and handpicked 

FM
FGIS Directive 9180.64 March 14, 2022

Page 8

(b) Alternate Procedure for Determining FM (Hand Sieve Method)

Official personnel have the option of manually hand-sieving or 

mechanically sieving (using a sizer shaker) the FM portion

Follow the procedures listed below to separate the component FM

1 Mechanically Sieving Method

a Mount a 5/64 or 6/64 round-hole hand sieve and a bottom 

collection pan on a mechanical sieve shaker

b Set the stroke counter to 5

c Add approximately 250 grams of the work portion to the sieve 

shaker

d Turn the sieve shaker on

e After the sieve shaker has stopped carefully remove the sieve 

and bottom collection pan

f Combine the material that lodged in the perforations with the 

material that remained on top of the sieve. Consider this

material as popcorn

g Consider the material in the bottom collection pan as foreign 

material

h Remove all matter other than popcorn from the mechanically 

cleaned portion and combine with the foreign material in step 

g above. This combination of mechanically separated FM and

hand-picked FM functions as foreign material

i Repeat the above steps until all of the sample has been 

sieved

j Calculate the percentage FM

2 Hand Sieving Method

a Mount a 5/64 or 6/64 round-hole hand sieve to a bottom 

collection pan

b Add approximately 250 grams of the work portion to the sieve.

c Hold the sieve level in both hands with elbows close to the 

body
FGIS Directive 9180.64 March 14, 2022

Page 9

d In a steady motion, move the sieve from left to right 

approximately 10 inches and then return from right to left.

e Repeat this operation 5 times

f Combine the material that lodged in the perforations with the 

material that remained on top of the sieve. Consider this

material as popcorn

g Consider the material in the bottom collection pan as foreign 

material

h Remove all matter other than popcorn from the mechanically 

cleaned portion and combine with the foreign material in step 

g above. This combination of mechanically separated FM and

hand-picked FM functions as foreign material

i Repeat the above steps until all of the sample has been sieved

j Calculate the percentage FM

(c) Certification. Record the percentage of FM on the certificate to the 

nearest tenth percent

(7) Stones

(a) Definition. Stones are concreted earthy or mineral matter and other

substances of similar hardness that do not readily disintegrate in water

(b) Basis of Determination. Determine stones on a representative portion of

approximately 1-1/8 to 1-1/4 quarts.

(c) Certification. Show stones on the work record and certificate to the 

nearest tenth percent

b. Factors Determined After the Removal of F

(1) Damaged Kernels

(a) Definition. Kernels and pieces of popcorn kernels that are badly

ground-damaged, badly weather-damaged, diseased, frost-damaged, 

germ-damaged, heat-damaged, insect-bored, mold-damaged, sproutdamaged, or otherwise materially damaged. A 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

(b) Basis of Determination. Determine damaged kernels on approximately 

125 grams of foreign material-free popcorn
FGIS Directive 9180.64 March 14, 2022

Page 10

(2) Types of Damage (Reference Images: Corn)

(a) Blue-eye Mold. A germ infected with blue-eye mold, regardless of the

amount. If the mold is distinct, it is not necessary to open or scrape the

kernel. Otherwise, lift the germ cover carefully to avoid destroying the

evidence of mold

Do not confuse purple plumule with blue-eye mold. Purple plumule is not

damage but is a genetic or varietal characteristic

(b) Cob Rot. Cob rot is caused by a fungus that attacks weakened plants. I

is detected by the presence of a distinct discoloration or rotting. Opening

the kernel is not required to detect cob rot but may be necessary to 

determine the extent of other types of damage.

(c) Drier-Damaged Kernels. Kernels and pieces of kernels which have

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

swollen and slightly discolored and which often have damaged germs; 

or whose seedcoats are peeling off or have already peeled off; or which 

have a fractured or checked appearance resulting from external heat 

caused by artificial drying methods. Do not confuse drier damage with 

heat damage (drier)

(d) Germ-damaged Kernels (Slight Discoloration By Respiration). Kernels

and pieces of kernels damaged by respiration or heat but not materially 

discolored

In most cases, the germ covering will have to be removed, exposing the 

area around the plumule. The discoloration must extend into the meat of 

the germ to be considered damaged

(e) Heat-Damaged Kernels. Kernels and pieces of kernels which are

materially discolored by excessive respiration, with the dark discoloration 

extending out of the germ through the sides and into the back of the 

kernel

(f) Heat-Damaged Kernels (Drier). Kernels and pieces of kernels, which ar

puffed or swollen and materially discolored and damaged by external 

heat caused by artificial drying methods. Determine heat-damaged 

kernels on a portion of 125 grams of FM-free popcorn

Record the percent of heat-damaged kernels on the certificate to the 

nearest tenth percent
FGIS Directive 9180.64 March 14, 2022

Page 11

(g) Insect-Bored Kernels. Kernels and pieces of kernels with obvious insectbored holes or which have tunneling, insect webbing, or insect refus

Do not consider kernels partially eaten but entirely free from refuse, 

webbing, insects, or other forms of damage as damaged. Do not cut

open the kernel when making this determination. If the determination

cannot be made without cutting the kernel, the kernel is considered 

damaged

(h) Mold-Damaged Kernels. Kernels and pieces of kernels infected with

mold on exposed endosperm. When a kernel of popcorn has been 

broken exposing the starch, it becomes susceptible to mold. Check 

broken pieces carefully for mold

(i) Mold-like Substance. Whole kernels of popcorn that are 50 percent or

more covered and pieces of kernels which are discolored and covered 

with a mold-like substance. Do not confuse kernels that have dirt on

them with kernels containing mold. Mold is usually blue or green in colo

(j) Silk-Cut Kernels. Kernels and pieces of kernels with mold in silk-cut

Kernels with clean silk cuts and are otherwise sound are not considered 

as being damaged

(k) Surface Mold (Blight). Kernels and pieces of kernels which have mold

caused by popcorn leaf blight on them which appears to be only on the 

surface but actually penetrates the seed coats

(l) Surface Mold. Kernels and pieces of kernels, which contain surface,

mold in any area or combination of areas equal to or greater than shown 

on the visual reference image

(m) Mold (pink Epicoccum). Kernels and pieces of kernels with germs

infected with mold

(n) Sprout-Damaged Kernels. Sprouted kernels or those showing evidence

of a sprout

(o) Certification. Record the percent of damaged kernels on the pan ticket

and certificate to the nearest tenth percent.
FGIS Directive 9180.64 March 14, 2022

Page 12

(3) Color

There are no subclasses in Popcorn. Popcorn is either white or yellow in

color

(a) Certify the lot as popcorn without any description of color (e.g., yellow

white, mixed).

(b) Upon request, the percentage of yellow and/or white kernels can be 

determined

(c) When the percentage of color is requested, make this determination on a 

representative portion of approximately 125 grams.

(d) Record the percentage of white and/or yellow kernels in the sample 

portion on the work record and the certificate in whole percentages.

8. TYPE OF SERVICES

a. Lot Inspection Service requires FGIS or an authorized cooperator to obtain

a representative sample from an identified lot using the following procedures and 

forwarding the sample to the Technical Services Division, Quality Systems and 

Services Unit (QSS) for popping ratio testing

(1) Maximum Lot Size.

(a) The maximum lot size is 500,000 lbs. (225,000 kg.).

(b) If the lot exceeds the maximum lot size, inform the applicant that

the lot will have to be divided into smaller lots that do not exceed the 

maximum lot size.

(2) Sample Rates

The following table shows the number of individual containers or the time 

intervals to use for obtaining sample portions

Lot Size In Pounds Lot Size In Kilograms Number of Containers or 

Time Intervals Per Lot

45,000 or less

45,001 - 180,000

180,001 - 500,000

20,250 or less

20,251 - 81,000

81,001 - 225,000

12

20

35

b. Submitted Sample Inspection Service consists of an applicant obtaining and

forwarding a sample to QSS through a field office for testing. The applicant must 

identify the sample and send it to the local FGIS field office or QSS for popping 

ratio testing
FGIS Directive 9180.64 March 14, 2022

Page 13

9. LEVEL OF SERVICE

a. Original service is the initial inspection of a lot or a submitted sampl

b. Field Office or TSD personnel will perform only one appeal inspection on any 

original inspection service. An applicant may request an appeal inspection on any

of the kinds of inspection services performed for an original inspection. For appeal

inspections, the field office and/or TSD can analyze the specified quality factor(s) 

that would be predetermined during an appeal or a Board appeal.For appeal

inspections of analytical factors, however, the QSS must perform the analysis

c. An applicant who is dissatisfied with the original or appeal inspection results may 

appeal to the FGIS Board of Appeals and Review (BAR). The Board appeal

is limited to an analysis of the file sample. When a request for a Board appeal 

inspection is filed, the file sample(s) and all other pertinent information will be 

immediately submitted to the BAR. The field office will act as a liaison between the 

BAR and the applicant

10. TESTING SERVICE

a. Testing will be performed at the Technical Services Division, QSS. Intereste

persons wishing to receive these testing services may contact QSS directly or 

request service through their local field office or an authorized cooperator to 

arrange for service. Application forms may be obtained from FGIS field offices.

b. QSS will, upon request, provide popping ratio on all submitted and official file 

samples

c. Field personnel will maintain representative file samples when official sampling 

services are provided. FGIS personnel and cooperators will forward samples for

testing to QSS. QSS will maintain a file sample (balance of the representative 

portion after testing) on each original, retest, and appeal inspection service

d. QSS uses a Metric Weight Volume Tester (MWVT) approved by the Popcorn

Institute in the determination of popping ratio. Samples are analyzed 1 or 2

business days after QSS receives the sample. Results are immediately reported

to the appropriate FGIS field office or cooperator after analyses are recorded by 

QSS. (see section 11 b., Certification and Billing).

e.  For MWVT information, cooperators and interested parties in the popcorn industr

may obtain a copy of the basis guideline for the MWVT at the following address:

Popcorn Board

401 N. Michigan Av

Chicago, IL 60611-4267

Phone: (312) 644-6610

Fax: (312) 321-6869
FGIS Directive 9180.64 March 14, 2022

Page 14

11. CERTIFICATION

a. Type of Certificate. Certify the analysis of popcorn on officially sampled lots on

a commodity inspection certificate (FGIS-993). Issue a submitted sample certificate 

(FGIS-994) for samples submitted by an applicant or their agent

b. Certification and Billing. For all popping ratio service performed by QSS, the field

office or cooperator nearest the location where the request originated will issue 

the applicable certificate(s) based on the results from QSS and complete the 

billing. Testing fees will be assessed in accordance with section 868.90 of the AM

regulations

c. Popping Ratio Unit of Measure. The appropriate field office/cooperator will show

the popping value on the work record and certificate in cubic centimeters of 

popped corn per gram of raw corn

12. QUESTIONS

Direct any questions concerning this directive to the Policies, Procedures, and Market 

Analysis Branch at (202) 720-0228