United States

Department of

Agriculture

Marketing and

Regulatory

Programs

Agricultural

Marketing 

Service

Fruit and 

Vegetable

Programs

Processed 

Products 

Branch

Grading Manual 

for 

Peanut Butter

Effective April 2011
1

This manual is designed for Processed Products Branch personnel of the U.S. 

Department of Agriculture. Its purpose is to give background information and guidelines 

to assist in the uniform application and interpretation of U.S. grade standards, other 

similar specifications and special procedures.

The citation of any data, techniques, illustrations, copyrighted material, or pictorial 

representation accredited to private authorship is used with the permission of the 

individuals or sources cited. Unless a specific reference is cited, the information in this 

manual has been compiled or developed from sources available to the public as well as 

from technical knowledge of personnel in the Department.

Compliance with the suggested guidelines in this manual does not excuse failure to 

comply with the Federal Food, Drug, and Cosmetic Act or any other applicable Federal 

or State laws or regulations.

Except for official USDA inspection aids or devices and color guides (or standards) 

produced under license of the Department, the mention of any supplier, patented 

device, product, brand name or equipment does not imply endorsement by the 

Department over any other similar, or equally effective, material.

Address inquiries to:

Chief, Processed Products Branch

Fruit and Vegetable Programs, AMS

U.S. Department of Agriculture

STOP 0247

1400 Independence Ave., SW

Washington, DC 20250-0247
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April 2011

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TABLE OF CONTENTS

Page

SAMPLING PROCEDURES ........................................................................................... 3

NONQUALITY INSPECTION PROCEDURES................................................................ 3

SUGGESTED ORDER FOR LOT GRADING OF A SAMPLE......................................... 4

SUGGESTED ORDER FOR ON-LINE GRADING OF A SAMPLE UNIT........................ 6

SPECIAL ON-LINE SITUATIONS................................................................................. 10

TECHNICAL SECTION................................................................................................. 11

 List of Equipment..................................................................................................... 12

 List of Chemicals...................................................................................................... 12

 Preparation of Pancreatin Extract............................................................................. 13

 Methods of Analysis

 Basic steps-WIIR, Light Filth, Heavy Filth, Texture .................................................. 13

 Salt........................................................................................................................... 17

 Texture..................................................................................................................... 17
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SAMPLING PROCEDURES

1. LOT (Stationary lot.) Follow:

- Regulations (File Code 109-A-1)

- Sampling Procedures (File Code 120-A-1)

 - Condition of Container (File Code 125-A-1)

- Determination of Salt Content (File Code 135-A-19)

- Foreign Material (File Code 172-A-1)

- The Food Defect Action Levels (File Code 172-A-2)

- Aflatoxin Analysis of Peanut Butter and Other Peanut Products (File 

Code 172-A-3)

2. ON-LINE (Moving Lot.) Follow:

- Regulations (File Code 109-A-1)

- In Process (On-Line) Sampling Acceptance and

- Segregation Procedures for Quality Factors (File Code 120-A-4)

- In Plant Inspection (File Code 160-A-1)

 - Condition of Container (File Code 125-A-1)

- Determination of Salt Content (File Code 135-A-19)

- Foreign Material (File Code 172-A-1)

- The Food Defect Action Levels (File Code 172-A-2)

- Aflatoxin Analysis of Peanut Butter and Other Peanut Products (File 

Code 172-A-3)

NONQUALITY PROCEDURES

1. Time Sampling (File Code 120-A-5)

2. Net Weight (File Code 128-A-10)

3. Fill of Container (File Code 128-A-40)

4. General Inspection Procedures (File Code 130-A-1)

5. Vacuum (File Code 128-A-20)
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April 2011

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SUGGESTED ORDER FOR LOT GRADING OF A SAMPLE

Inspectors performing lot inspections should use the applicable procedures provided for 

on-line grading. In addition, for lot inspection of peanut butter, the following guidance 

applies:

 

1. Check the flavor and odor of a sample first, and then continue as shown for 

on-line grading (steps 1 through 6).

2. For consistency, allow sample to naturally cool to 70°F to 80°F (21°C to 

27°C). Do not remove samples and cool artificially (e.g., in a cooler or water 

bath). Do not assign a final score for Consistency until samples have been 

permitted to equalize, a Minimum of 48 hours after packing. 

Upon opening a container of peanut butter, carefully check the surface for the 

presence of free oil -- both in stabilized and nonstabilized types. Free oil in 

nonstabilized peanut butter is considered normal, but not in stabilized peanut 

butter.

NOTE THAT THE NATURAL GLOSS OF THE PRODUCT IS NOT 

CONSIDERED "FREE OIL".

For stabilized peanut butter, it has been administratively determined that any free 

oil that may be present in:

U.S. Grade A - cannot be poured off or collected, and does not flow 

when container is tilted.

U.S. Grade B - can be poured, and/or flows when the container is 

tilted, and/when collectable -- such collectable oil 

does not exceed 1 cubic centimeter (mL) per pound of 

product.

Check through the entire sample to be sure there are no pockets of oil below the 

surface. The bottoms of sample containers should also be checked for free oil or 

excessive dryness.

For non-stabilized peanut butter, slight to moderate mixing to disperse the 

separated oil should be possible in 30 to 35 seconds.
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SUGGESTED ORDER FOR LOT GRADING OF A SAMPLE (continuation)

3. Sampling rates for Water Insoluble Inorganic Residues (WIIR), and light and 

heavy filth are in accordance with file codes 172-A-1 and 172-A-2.

4. Analyze each sample unit for salt content. Perform analysis using either Mohr 

Method or Conductivity (Salt Meter Method) in accordance with file code 

135-A-19, Determination of Salt Content. Salt content is expressed as percent 

by weight. Use sample size specified in the instructions for each salt test 

method; if no sample size is specified, use a sample size of 5 grams.
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SUGGESTED ORDER FOR ON-LINE GRADING OF A SAMPLE UNIT

1. Evaluate each sample unit for flavor and odor. Evaluate the flavor and odor 

quickly, as soon as the container is opened. The first impression is the best 

because the taste and smell sensations are quickly satisfied. Often, further

flavor and odor evaluations of the sample fail to give reliable results. Good 

flavor is the result of properly roasted peanuts (neither under roasted nor over 

roasted) blended with the right proportion of additives (salt, sugar, honey, 

dextrose, etc.) for the particular type, style, and texture of peanut butter being 

produced. Good flavor in light brown, non-stabilized, medium texture "old 

fashioned" peanut butter cannot be used as a guide for evaluating the flavor 

of a dark brown, stabilized, smooth texture peanut butter containing all the 

permitted additives. The flavor should be evaluated based on the ideal for the 

particular style, type, and texture. The degree of roast has a great influence 

on flavor, odor and color. Peanut butter with good color could be expected to 

have better flavor than peanut butter with less than good color. The aroma of 

peanut butter should be that of freshly roasted and ground peanuts. The 

aroma must be free from musty, rancid, moldy, or any other objectionable 

odor. Record the flavor score after determining salt content, step 2, below.

2. Analyze each sample unit for salt content. The salt content is required 

to assign a flavor score; analyze all sample units. Perform analysis using 

either Mohr Method or Conductivity (Salt Meter Method) in accordance with 

file code 135-A-19, Determination of Salt Content. Salt content is expressed 

as percent by weight. Use sample size specified in the instructions for each 

method; if no sample size is specified, use a sample size of 5 grams.

3. Analyze the sample unit for Water Insoluble Inorganic Residue (WIIR), 

Light Filth and Heavy Filth by following the instructions in Technical Section 

of this manual. These tests are required to determine compliance with the 

U.S. Food and Drug Administration requirements (see File Codes 172-A-1

and 172-A-2). Products which fail these tests fail to meet the requirements of 

the Federal Food, Drug and Cosmetic Act and cannot be assigned a grade. 

Please contact your supervisor if this situation occurs. WIIR level is also a 

factor for determining U.S. grade.

NOTE: ALSO SEE TEXTURE, pages 7 and 17.

It is not practical to run a WIIR on every sample unit. If No. 1 peanuts are 

being used and the history of plant operations indicates WIIRs of less than 5 

mg per 100 grams of product can be anticipated, one determination per eight 
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April 2011

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SUGGESTED ORDER FOR ON-LINE GRADING OF A SAMPLE UNIT (continuation)

hour shift is sufficient. If WIIRs are running above 5 mg per 100 grams of 

product, perform one determination for every eight quality samples with a

minimum of two per eight hour shift. If WIIRs are close to the upper limit, a 

WIIR should be run for every four quality samples, with a minimum of three

per eight hour shift. See pages 11 through 15 of this manual for the 

procedures for running WIIR. Light filth and heavy filth are run on the residue 

and the decanted material obtained in the BASIC STEPS of the WIIR 

determination. See pages 13 through 17 of this manual for the procedure for 

running light filth or heavy filth. The sampling rates for light filth and heavy 

filth are specified in File Code 172-A-1.

4. Evaluate the color of each sample unit. With a spatula, place a smear of 

peanut butter (about 1/2 inch wide and about 2 inches long) on white paper. 

Spread the smear to about the area and depth of the peanut butter color 

standards. A wide spatula, with a groove the correct width and depth, is an 

invaluable aid for getting the peanut butter smear to the correct size and 

depth for evaluating its color using the plastic color comparators. With a 

small spatula, remove the sheen from the top of the prepared sample. Select 

the two color standards that most closely match the color of the peanut butter. 

Place the color standards on each side of the prepared sample and, using the 

Macbeth Examolite or other approved lighting source, classify and record

the color designation and assign score points for the factor of color. 

Information for obtaining color standards for peanut butter is available at:

http://www.ams.usda.gov/processedinspection.

 5. Evaluate each sample unit for dark particles using Inspection Aid No. 95. 

Follow the instructions included on the aid and evaluate the sample for 

defects by comparing the sample unit with Photo-Guides for Peanut Butter 

Illustrating Dark Particles in Peanut Butter, PG-4. Record the score for the 

factor of defects. Information for obtaining PG-4 for peanut butter is available 

at: http://www.ams.usda.gov/processedinspection.

6. Determine the texture of each sample unit. Generally texture can be 

determined by spreading a subsample on a grading tray, and observing the 

size of the peanut particles. In borderline situations the texture should be 

determined as outlined on page 16 of this manual.

7. Evaluate the sample unit for consistency. Consistency refers to the 

spreadability of the product and to the amount of oil separation in either 

stabilized or nonstabilized type peanut butter. Peanut butter should set 
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April 2011

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SUGGESTED ORDER FOR ON-LINE GRADING OF A SAMPLE UNIT (continuation)

undisturbed after packaging and palletizing and reach an internal temperature 

between 70°F and 80°F (21°C and 27°C) before consistency is evaluated. 

Allow sample to naturally cool to 70°F to 80°F (21°C to 27°C). Do not cool 

artificially (e.g., in a cooler or water bath). Do not assign a final score for 

consistency until samples have been permitted to equalize, a minimum of 48 

hours after packing. (Unless otherwise specified by the contract or purchase 

order.)

Upon opening a container of peanut butter, carefully check the surface for the 

presence of free oil -- both in stabilized and nonstabilized types. A slight 

amount of free oil in nonstabilized peanut butter is considered normal, but not 

in stabilized peanut butter.

THE NATURAL GLOSS OF THE PRODUCT IS NOT CONSIDERED 

"FREE OIL".

For stabilized peanut butter, it has been administratively determined that 

any free oil that may be present in:

U.S. Grade A - cannot be poured off or collected, and does not flow 

when container is tilted.

U.S. Grade B - can be poured, and/or flows when the container is 

tilted, and/when collectable -- such collectable oil 

does not exceed 1 cubic centimeter (mL) per pound of 

product.

Check through the entire sample to be sure there are no pockets of oil 

below the surface. The bottoms of sample containers should also be 

checked for free oil or excessive dryness.

For non-stabilized peanut butter, slight to moderate mixing to disperse the 

separated oil should be possible in 30 to 35 seconds.

Peanut butter must not be abnormally sticky in U.S. Grade A. Excessive 

stickiness can be caused by: incorrect setting for the fineness of grind, 

improper cooling time, or by altering the percentages of added ingredients.
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SUGGESTED ORDER FOR ON-LINE GRADING OF A SAMPLE UNIT (continuation)

Noting that peanut butter is used primarily as a spread for bread, the 

consistency for U.S. Grade A should be such that it spreads easily on 

fresh bread (having a moderately dense crumb) without appreciable 

tearing or breaking of the bread.

Consistency may be checked by drawing the flat side of a table knife 

(blade about 3/4 inches wide) through the peanut butter. The blade 

should be inserted approximately 2-1/2 inches into the peanut butter and 

held at an approximate 45° angle. If there is more than a slight resistance 

to drawing the knife through the peanut butter or the product is so thin that 

the path collapses within about 3 seconds, the peanut butter should not be 

graded above U.S. Grade B.

Peanut butter may also lack U.S. Grade A consistency because it hasn't 

set properly. Product with a gelatin like consistency is the result of a poor 

set. This may not be evident upon opening the container but can develop 

a short time after the surface of the product is disturbed. After the sample 

unit has been opened:

a. Perform a 45° angle cut through the product.

b. On samples that are borderline "Soft" or "Thin," proceed as follows:

1. Using a table knife, remove portions of the product from the 

container. (Follow normal procedure in spreading product on 5-6 

slices of bread.)

2. Perform another 45° angle cut through the product. If the 

product has developed a gelatin like condition that is more than 

slightly noticeable or if the knife path collapses within about 3 

seconds, the peanut butter should not be graded above 

U.S. Grade B.
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SUGGESTED ORDER FOR ON-LINE GRADING OF A SAMPLE UNIT (continuation)

SPECIAL ON-LINE SITUATIONS

Government Contracts.

In addition to the grade determination, the inspector checks other requirements (such as 

markings, coding) when Government contracts are being run. Review the terms of the 

contract and specifications for any special requirements and verify these requirements 

with your supervisor. Follow instructions in File Codes 147-A-22, Inspection of FSA 

Peanut and Peanut Products, and 172-A-3 for submission of samples for aflatoxin 

testing. The Branch may implement review programs to ensure uniform application of 

procedures and delivery of compliant product to applicants. 
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TECHNICAL SECTION

This section describes technical procedures for performing:

Water Insoluble Inorganic Residue (WIIR);

Light Filth;

Heavy Filth; and 

Texture (used in borderline cases.)

It is Branch policy to perform these tests to confirm that peanut butter graded by the 

Branch does not exceed FDA Defect Action Levels (DALs). (See File Codes 172-A-1 

and 172-A-2.) Products which fail these tests fail to meet the requirements of the 

Federal Food, Drug and Cosmetic Act and cannot be assigned a grade. Please contact 

your supervisor if this situation occurs. Note that WIIR level is also a factor for 

determining U.S. grade. The U.S. Standards for Grades of Peanut Butter indicate these 

tests are performed in accordance with the latest official methods outlined in the Official 

Methods of Analysis of the Association of the Official Analytical Chemists (AOAC) or 

any other method that gives equivalent results.

The Light and Heavy Filth Test Methods in this Manual may be used for determining 

light and heavy filth in peanut butter. Light filth and heavy filth are run on the residue 

and the decanted material obtained in the BASIC STEPS of the WIIR.

AOAC Method 968.35, section B may also be used to obtain material for running light 

and heavy filth.

Alternatively, samples for WIIR and Light and Heavy Filth determination may be sent to 

designated field offices for analysis.

Since corrosive, explosive, and/or cumulatively toxic chemicals are used in the following 

procedures, follow current Branch instructions for laboratory safety. All analyses should 

be conducted under a suitable laboratory fume hood. Uncontrolled open flames shall 

not be permitted.

NOTE: THESE PROCEDURES MAY BE USED IN APPROVED, 

PROPERLY EQUIPPED LABORATORIES ONLY. IF IN DOUBT 

CONSULT YOUR SUPERVISOR.
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TECHNICAL SECTION (continuation)

1. List of Equipment

Balance, triple beam, with 0.1 g precision.

Balance, analytical, with 0.1 mg precision.

Boiling Chips

Beakers, Griffin, low form plastic or Pyrex - 250 mL, 600 mL

Bottles, wash - 250 mL polyethylene

Brush, camel’s hair

Burner, Bunsen

Burettes, 100 mL capacity, with 0.1 mL precision.

Crucibles, Platinum or silica

Cylinder, graduated, 100 mL graduated in 0.5 mL

Dish, platinum or silica

Flask, Erlenmeyer, w/rubber stopper - 250 mL, 500 mL, 2 L

Flask, vacuum - 500 mL or 1000 mL

Funnel, Buchner, 15 cm

Funnel 60°, short stem, 4 or 5 inch diameter

Furnace, muffle - 0° to 500° C

Glass, watch - 3 or 4 inch diameter

Microscope, wide field - 20X and 30X

Paper, rapid filter - ashless 15 cm

pH meter

Pump, acid, calibrated to 0.1 mL

Rods, stirring, plastic (or glass w/policeman)

Sieves, U.S. Standard 20, 30, and 40 mesh, fine series, 8 inch

Thermometer, 0° to 100°C

Vacuum source

Water bath

Wildman trapflask

2. List of Chemicals (Unless noted, all chemicals should be reagent grade.)

Acid, Hydrochloric, HCl

Chloroform, CHCl3

Ether, petroleum

Formaldehyde, HCOH

Kerosene, commercial

Pancreatin, Merck, U.S.P. (keep refrigerated at 10°C or 50°F)

Sodium phosphate, tribasic, Na3PO4.12H2O (5%)
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TECHNICAL SECTION (continuation)

3. Preparation of Pancreatin Extract (for Light Filth)

a. Standard Procedure

i. Mix 5 grams of pancreatin with 100 mL of warm water (not over 40°C or 

104°F) for 10 minutes in a blender, or allow to stand for 30 minutes with 

intermittent stirring.

ii. Filter solution through 4 inches of loosely packed cotton in a 60° funnel.

iii. Repeat filtering, using the same cotton. (If filtering is very slow, cotton 

may be changed.)

iv. Filter with suction through a fast filter paper in a Buchner funnel.

NOTE: IF FILTERING IS SLOW, POUR THROUGH A SLIGHTLY 

COMPRESSED COTTON PLUG IN A 60° FUNNEL. REPEAT IF 

NECESSARY UNTIL RAPID FILTRATION THROUGH PAPER IS 

OBTAINED.

b. Alternate Procedure

Mix 10 grams of pancreatin with 100 mL of warm water, allow to stand for 

2-1/2 hours and proceed as indicated for the standard pancreatin extract.

4. WATER INSOLUBLE INORGANIC RESIDUE (WIIR), LIGHT FILTH, HEAVY 

FILTH, TEXTURE

NOTE: CHLORIDE FREE, DISTILLED WATER (ONLY) SHOULD BE USED 

IN THESE ANALYSES.

METHODS OF ANALYSIS

a. Basic steps - WIIR, Light Filth, Heavy Filth, Texture

Steps 1 through 19 are common to the WIIR, light filth, heavy filth, and 

texture.

NOTE: STEP 12: THE DECANTED PETROLEUM ETHER FROM THE 

PREVIOUS STEPS IS TO BE DISCARDED.
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April 2011

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TECHNICAL SECTION (continuation)

(1) Weigh 100 grams of subsample into a tared 250 mL beaker.

(2) Add 10 mL of petroleum ether and mix thoroughly.

(3) Gradually add approximately 140 mL of petroleum ether, mixing continually.

(4) Cover and allow to settle for 25 minutes.

(5) Float off light tissue by carefully decanting about 100 mL of the petroleum 

ether layer.

(6) Add approximately 125 mL of petroleum ether to the residue in the beaker, 

washing down the sides of the beaker with a stream of petroleum ether from 

the wash bottle, mix thoroughly.

(7) Cover and let settle for 15 minutes.

(8) Float off light tissue by carefully decanting about 100 mL of the petroleum 

ether layer.

(9) Add approximately 125 mL of petroleum ether to the residue, washing down 

the sides of the beaker with a stream of petroleum ether from the wash 

bottle, mix thoroughly.

(10) Cover and allow to settle for 10 minutes.

(11) Float off light tissue by carefully decanting about 100 mL of the petroleum 

ether layer.

(12) Discard all decanted petroleum ether, saving only the residue remaining in 

the beaker.

(13) Evaporate the remaining petroleum ether from the residue in the beaker 

using a water bath. (The evaporation may be accomplished in a fume hood 

by allowing the air flow to pass over the residue in the beaker).

(14) Add 100 mL of chloroform (CHCl3), washing down the sides of the beaker 

with a stream of chloroform from the wash bottle, mix thoroughly.

(15) Cover and allow to settle for 20 minutes, stirring the top layer several times 

while settling to dislodge any heavy filth trapped in the crust.

(16) Without disturbing the heavy residue at the bottom of the beaker - decant 

the CHCl3 and the floating peanut tissue into a clean beaker and SAVE.

(17) Repeat steps 14, 15, and 16 using CHCl3.

(18) Repeat steps 14, 15, and 16 making sure all particles are washed from the 

sides of the beaker.

(19) Save all decanted peanut tissue for later light filth or texture determination.

All of the residue in the beaker is used for the determination of heavy filth and 

WIIR.
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April 2011

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TECHNICAL SECTION (continuation)

(20) Heavy filth - Examine the residue in the beaker (from step 19 of the basic 

steps) for obvious contamination by sand, rodent excreta, or other heavy 

filth.

b. WIIR

METHOD I

(1) Wash the heavy residue from step 18, above, thoroughly several times with 

hot water. Carefully decant the hot water and discard.

(2) Dry the residue in the beaker on a hot plate or by standing in air.

(3) Transfer the dried residue to a tared crucible with the aid of a camel’s hair 

brush.

(4) Ignite the residue and dry in a muffle furnace at 500°C - 550°C. (932°F -

1022°F) for one hour.

(5) Weigh to the nearest 0.1 mg (0.0001 g) and round to nearest mg (0.001 g).

METHOD II

(1) Add 50 mL of dilute HCl (1+35) to the heavy residue in the beaker from step 

18. Add 90 mL hot water, stir thoroughly and allow to stand 30 minutes.

NOTE: ONE PART HCl TO 35 PARTS WATER.

(2) With the aid of a stream of hot water transfer the residue from the beaker to 

an ashless filter paper using a Buchner funnel and a vacuum source.

(3) Wash the filter paper thoroughly with hot water to ensure water soluble 

residue is dissolved.

(4) Transfer the filter paper to a tared crucible.

(5) Ignite the filter paper and dry in a muffle furnace at 500°C - 550°C. (932°F -

1022°F) for one hour. 

(6) Weigh to the nearest 0.1 mg (0.0001 g) and round to nearest mg (0.001 g).
Peanut Butter

April 2011

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TECHNICAL SECTION (continuation)

c. LIGHT FILTH - Light filth is run on the decanted peanut tissue from steps14 

through 18 of the basic steps.

NOTE: ALL TEMPERATURES STARTING WITH STEP 4 IN THIS 

PROCEDURE ARE OF A CRITICAL NATURE. SUFFICIENT 

MARGINS HAVE BEEN ALLOWED FOR MINOR 

FLUCTUATIONS. IF TEMPERATURE EXCEEDS 40°C (104°F) AT 

ANY POINT, DISCARD AND START OVER.

(1) Filter the decanted peanut tissue (from step 19 of the basic steps) through a 

rapid filter paper.

(2) Transfer all collected residue to a hard surface paper. Save the filter paper 

for later washing.

(3) Break up any caked or lumpy peanut material and dry. [Overnight at room 

temperature or for 1 hour in an oven at 80°C (176°F.)]

(4) Transfer the dry residue to a 600 mL beaker.

(5) Rinse the filter paper (saved from step 2) with cold water and add the 

washings to the beaker.

(6) Add 300 - 400 mL of cold water and stir until smooth.

(7) Add freshly prepared, filtered, aqueous pancreatin extract and mix. (Total 

volume of extract (approximately 100 mL) prepared as shown on page 12 is 

required for this step.)

(8) Adjust to pH 8.0 with Na3PO4 solution (5%), and set aside for 15 minutes.

(9) Re-adjust to pH 8.0 and set aside for 45 minutes.

(10) Re-adjust to pH 8.0 and proceed.

(11) Add 5 drops of formaldehyde, U.S.P.

(12) Allow mixture to “digest” for 16 to 18 hours in a warm oven 30°C - 37°C 

(86°F - 99°F).
Peanut Butter

 April 2011 

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TECHNICAL SECTION (continuation)

NOTE: DIGESTION MAY BE ACCOMPLISHED IN 2 1/2 HOURS BY USING 

THE ALTERNATE PANCREATIN EXTRACT ON PAGE 12 AND 

DIGESTING AT 37° - 39°C (99°F - 102°F).

(13) Cool to room temperature and transfer the digested material to a 2 liter 

Wildman trapflask.

(14) Add sufficient deaerated water to bring the volume to 800 or 900 mL.

(15) Add 35 mL of kerosene, agitate vigorously without breaking the surface or 

incorporating air into the mixture.

(16) Add sufficient deaerated water to raise the kerosene level into the neck of 

the flask.

(17) Allow to stand for 30 minutes.

(18) Trap off the kerosene into a beaker.

(19) Add 25 mL of kerosene to the flask, agitate vigorously without breaking the 

surface or incorporating air into the product. Allow to stand for 10 minutes.

(20) Trap off the kerosene layer into the beaker used in the step 18.

(21) Filter the kerosene fraction through a ruled, fast filter paper.

(22) Examine microscopically using a wide field microscope at 20X for scanning 

and at 30X for identification of light filth.

d. SALT

Salt in peanut butter is determined in accordance with the latest method in the 

Official Methods of Analysis of the Association of Analytical Communities 

(AOAC) International, or either the Mohr Method or Conductivity (Salt Meter 

Method) in accordance with File Code 135-A-19, or any other method 

approved by the Branch that gives equivalent results.

e. TEXTURE

This procedure should be used when there is a question about the texture of 
Peanut Butter

 April 2011 

18

TECHNICAL SECTION (continuation)

a sample. (Borderline situation).

(1) Pour all of the decanted material from steps 14, 15, 16, 17, and 18 of the 

basic steps through a nest of sieves, having as U.S. number 20 on top, a U.S.

number 30 in the middle, and a U.S. number 40 on the bottom.

(2) Allow to dry in the open air for 5 to 10 minutes.

(3) Shake moderately, allowing the dry peanut residue to pass through the 

sieves.

Classify the texture using the following guidelines.

Smooth texture - All the dried peanut residue passes through the U.S. number

20 sieve. Not more than one half gram is retained on the 

U.S. number 30 sieve.

Medium texture - More than one half gram of the dried peanut residue is 

retained on the U.S. number 30 sieve, with not more than 

one half gram being retained on the U.S. number 20 sieve.

Chunky or - More than one half gram of the dried peanut residue is 

Crunchy texture retained on the U.S. number 20 sieve.