Marketing and

Regulatory

Programs

Agricultural

Marketing 

Service

Specialty 

Crops

Program

Specialty

Crops

Inspection

Division

United States Standards

for Grades of Shelled 

Walnuts (Juglans regia)

September 21, 2017
This issue of the United States Standards for Grades of Shelled Walnuts (Juglans 

regia) (82 FR 39655) supersedes the previous issue which has been in effect since

September 1, 1968.

Voluntary U.S. grade standards are issued under the authority of the Agricultural 

Marketing Act of 1946, which provides for the development of official U.S. grades to 

designate different levels of quality. These grade standards are available for use by 

producers, suppliers, buyers, and consumers. As in the case of other standards for 

grades of fresh and processed fruits, vegetables, and specialty crops these 

standards are designed to facilitate orderly marketing by providing a convenient 

basis for buying and selling, for establishing quality control programs, and for 

determining loan values. 

The U.S. grade standards and inspection instructions for all fresh and processed fruits,

vegetables, and specialty crops are available on the internet and upon request at the 

address below. These documents provide detailed interpretations of the grade standards 

and provide step-by-step procedures for grading the product. 

Grade standards are issued by the U.S. Department of Agriculture (USDA) after careful 

consideration of all data and views submitted during rulemaking. The Department 

welcomes suggestions for improving the standards in future revisions. Comments may be 

submitted to, and copies of standards and inspection instructions obtained from: 

Director, Specialty Crops Inspection Division

Specialty Crops Program, 

USDA, Agricultural Marketing Service

1400 Independence Avenue, SW, STOP 0240 

Washington, D.C. 20250

__________________________________________________________________________

Authority: 7 U.S.C. 1621-1627. 

Note: Compliance with the provisions of these standards shall not excuse failure to 

comply with the provisions of the Federal Food, Drug, and Cosmetic Act, or 

with applicable State laws and regulations.

Non-Discrimination Policy: In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights 

regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA 

programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender 

expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, 

political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all 

bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. 

Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, 

American Sign Language, etc.) should contact the responsible Agency or USDA’s TARGET Center at (202) 720-2600 (voice and TTY) 

or contact USDA through the Federal Relay Service at (800) 877-8339. Additionally, program information may be made available in 

languages other than English. 

To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online 

at http://www.ascr.usda.gov/complaint_filing_cust.html and at any USDA office or write a letter addressed to USDA and provide in the 

letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632-9992. Submit your completed 

form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 

Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: program.intake@usda.gov. 

USDA is an equal opportunity provider, employer, and lender.
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

1

United States Standards for Grades of Shelled Walnuts (Juglans regia)

Section Page No.

General........................................................................................................................... 3

§51.2275 Application................................................................................................... 3

§51.2276 [Reserved]. .................................................................................................. 3

Grades............................................................................................................................ 3

§51.2277 U.S. No. 1.................................................................................................... 3

§51.2278 U.S. Commercial. ........................................................................................ 3

Reserved........................................................................................................................ 3

§51.2279 [Reserved]. .................................................................................................. 3

Tolerances for Grade Defects ...................................................................................... 4

§51.2280 Tolerances for grade defects....................................................................... 4

Color Requirements...................................................................................................... 4

§51.2281 Color classifications..................................................................................... 4

§51.2282 Tolerances for color..................................................................................... 4

§51.2283 Off color....................................................................................................... 5

Size Requirements ........................................................................................................ 5

§51.2284 Size classification. ....................................................................................... 5

§51.2285 Tolerances for size. ..................................................................................... 6

Application of Tolerances ............................................................................................ 6

§51.2286 Application of tolerances.............................................................................. 6

Definitions...................................................................................................................... 6

§51.2287 Well dried..................................................................................................... 6

§51.2288 Clean. .......................................................................................................... 7

§51.2289 Shell............................................................................................................. 7

§51.2290 Insect injury. ................................................................................................ 7

§51.2291 Rancidity...................................................................................................... 7

§51.2292 Damage....................................................................................................... 7
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

2

§51.2293 Serious damage. ......................................................................................... 8

§51.2294 Very serious damage................................................................................... 8

§51.2295 Half kernel. .................................................................................................. 9

§51.2296 Three-fourths half kernel.............................................................................. 9
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

3

General

§51.2275 Application.

The standards contained in this subpart apply only to walnuts commonly known as 

English or Persian walnuts (Juglans regia). They do not apply to walnuts commonly 

known as black walnuts (Juglans nigra).

§51.2276 [Reserved].

Grades

§51.2277 U.S. No. 1.

“U.S. No. 1” consists of portions of walnut kernels which are well dried, clean, free from 

shell, foreign material, insect injury, decay, rancidity, and free from damage caused by 

shriveling, mold, discoloration of the meat, or other means. (See §51.2280.) 

(a) Color shall be specified in connection with this grade in terms of “extra light,”

“light,” “light amber,” or “amber” from the USDA Walnut Color Chart or in terms of 

“red” color. The color classifications in the USDA Walnut Color Chart shall not 

apply to “red” color. Furthermore, “red” color shall not be mixed with “extra light,” 

“light,” “light amber,” or “amber” colors. (See §51.2281 and §51.2282.)

(b) Size shall be specified in connection with this grade in terms of one of the size 

classifications. (See §51.2284 and §51.2285.)

§51.2278 U.S. Commercial.

“U.S. Commercial” consists of portions of walnut kernels which meet the requirements 

of U.S. No. 1 grade, except for increased tolerances. (See §51.2280.)

(a) Color of walnuts based on the USDA Walnut Color Chart shall be not darker than 

the “amber” classification. There are no color requirements for “red” color. Color 

may be specified in connection with the grade in terms of one of the color 

classifications in the USDA Walnut Color Chart or “red” color. “Red” color shall 

not be mixed with “extra light,” “light,” “light amber,” or “amber” colors. (See 

§51.2281 and §51.2282.)

(b) Size shall be specified in connection with this grade in terms of one of the size 

classifications. (See §51.2284 and §51.2285.)

Reserved

§51.2279 [Reserved].
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

4

Tolerances for Grade Defects

§51.2280 Tolerances for grade defects.

(a) All percentages shall be calculated on the basis of weight. 

(b) In order to allow for variations, other than for color and size, incident to proper 

grading and handling, tolerances shall be permitted for the respective grades as 

indicated in Table I:

Table I

Grade

Tolerances for grade defects

Total defects Serious damage Very serious 

damage

Shell and foreign 

material

U.S. No. 1 5% 2% (included in 

5% total defects).

1% (included in 2%

serious damage).

0.05% (included in 1%

very serious damage).

U.S. Commercial 8% 4% (included in 

8% total defects).

2% (included in 4%

serious damage).

0.05% (included in 2%

very serious damage).

Color Requirements

§51.2281 Color classifications.

The following color classifications are provided to describe the color of any lot:

(a) “Extra light," "light," "light amber," and "amber:” The portions of kernels in the lot 

shall be not darker than the darkest color permitted in the specified classification 

as shown on the USDA Walnut Color Chart.

(b) “Red:” There are no color requirements.

§51.2282 Tolerances for color.

(a) All percentages shall be calculated on the basis of weight.

(b) In order to allow for variations incident to proper grading and handling, tolerances 

shall be permitted for the respective color classifications as indicated in Table II:
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

5

Table II

Color 

classification

Tolerances for color

Darker than 

extra light1 Darker than light1 Darker than light amber1

Darker than 

amber1

Extra light 15%

2% (included in 

15% darker than 

extra light).

----- -----

Light ----- 15%

2% (included in 

15% darker than 

light).

-----

Light amber ----- ----- 15%

2% (included in 

15% darker than 

light amber).

Amber ----- ----- ----- 10%

Red ------ ----- ----- -----

1See illustration of this term on USDA Walnut Color Chart.

§51.2283 Off color.

The term “off color” is not a color classification, but shall be applied to any lot which fails 

to meet the requirements of the “amber” classification when applying the color 

classifications in the USDA Walnut Color Chart. Off color shall not be used for “red” 

color.

Size Requirements

§51.2284 Size classification.

The following classifications are provided to describe the size of any lot: “Halves”, 

“Pieces and Halves”, “Pieces” or “Small Piece”. The size of portions of kernels in the lot 

shall conform to the requirements of the specified classification as defined below:

(a) Halves. Lot consists of 85 percent or more, by weight, half kernels, and the 

remainder three-fourths half kernels. (See §51.2285.)

(b) Pieces and halves. Lot consists of 20 percent or more, by weight, half kernels, 

and the remainder portions of kernels that cannot pass through a sieve with 

24/64 inch round openings. When a lot exceeds this minimum requirement, the 

actual percentage of halves may be specified. (See §51.2285.)

(c) Pieces. Lot consists of portions of kernels that cannot pass through a sieve with 

24/64 inch round openings. (See §51.2285.)

(d) Small pieces. Lot consists of portions of kernels that pass through a sieve with 
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

6

24/64 inch round openings, but that cannot pass through a sieve with 8/64 inch 

round openings. When desired, the actual size ranges within such size ranges 

may be specified. (See §51.2285.)

§51.2285 Tolerances for size.

(a) All percentages shall be calculated on the basis of weight.

(b) In order to allow for variations incident to proper sizing and handling, tolerances 

shall be permitted for the respective size classifications as indicated in Table III:

Table III

Size 

classification

Tolerances for size

Smaller than 

3/4 halves

Will not pass 

through 24/64 

inch round 

hole

Pass through 

24/64 inch 

round hole

Pass through 

16/64 inch 

round hole

Pass through 

8/64 inch 

round hole

Halves 5% ----- ----- 1% (included 

in 5%) -----

Pieces and 

halves1 ----- ----- 18% 3% (included 

in 18%)

1% (included 

in 3%)

Pieces ----- ----- 25% 5% (included 

in 25%)

1% (included 

in 5%)

Small pieces2 ----- 10% ----- ----- 2%

1No part of any tolerance shall be used to reduce the percentage of halves required or specified in a lot of 

“pieces and halves.” 2The tolerances of 10% and 2% for “small pieces” classification shall apply, respectively, to any smaller 

maximum or any larger minimum sizes specified.

Application of Tolerances

§51.2286 Application of tolerances.

The tolerances provided in these standards are on a lot basis, and they shall be applied 

to a composite sample representative of the lot. However, any container or group of 

containers in which the walnuts are obviously of a quality materially different from that in 

the majority of containers shall be considered a separate lot, and shall be sampled 

separately.

Definitions

§51.2287 Well dried.

“Well dried” means that the portion of kernel is firm and crisp, not pliable or leathery.
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

7

§51.2288 Clean.

“Clean” means that the appearance of the individual portion of kernel, or of the lot as a 

whole, is not materially affected by adhering dust, dirt or other foreign material.

§51.2289 Shell.

“Shell” means the outer shell and/or the woody partition from between the halves of the 

kernel, and any fragments of either.

§51.2290 Insect injury.

“Insect injury” means that the insect, web, frass or other evidence of insects is present 

on the portion of kernel.

§51.2291 Rancidity.

“Rancidity” means that the portion of kernel is noticeably rancid to the taste. Rancidity 

should not be confused with a slightly astringent flavor of the pellicle (skin) or with 

staleness (the stage at which the flavor is flat but not objectionable).

§51.2292 Damage.

“Damage” means any defect, other than color, which materially affects the appearance, 

or the edible or shipping quality of the individual portion of kernel, or of the lot as a 

whole. Any one of the following defects or any combination of defects the seriousness 

of which exceeds the maximum allowed for any one defect shall be considered as 

damage:

(a) Shriveling when more than one-eighth of the portion of kernel is severely 

shriveled, or a greater area is affected by lesser degrees of shriveling producing 

an equally objectionable appearance, except that kernels which are thin in crosssection but which are otherwise normally developed shall not be considered as 

damaged;

(b) Mold when plainly visible;

(c) Discoloration of the meat when more than one-eighth the volume of the portion 

of kernel is severely discolored, or a greater volume is affected by lesser degrees 

of discoloration producing an equally objectionable appearance;

(d) Not well dried; and,

(e) Not clean.
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

8

§51.2293 Serious damage.

“Serious damage” means any defect, other than color, which seriously affects the 

appearance, or the edible or shipping quality of the individual portion of kernel or of the 

lot as a whole. Any one of the following defects or any combination of defects the 

seriousness of which exceeds the maximum allowed for any one defect shall be 

considered as serious damage:

(a) Shriveling when more than one-fourth of the kernel is severely shriveled, or a 

greater area is affected by lesser degrees of shriveling producing an equally 

objectionable appearance;

(b) Mold when plainly visible on more than one-eighth of the surface of the kernel in 

the aggregate; and,

(c) Discoloration of the meat when more than one-fourth the volume of the portion 

of kernel is severely discolored, or a greater volume is affected by lesser degrees 

of discoloration producing an equally objectionable appearance.

§51.2294 Very serious damage.

“Very serious damage” means any defect, other than color, which very seriously affects 

the appearance, or the edible or shipping quality of the individual portion of kernel or of 

the lot as a whole. Any one of the following defects or any combination of defects the 

seriousness of which exceeds the maximum allowed for any one defect shall be 

considered as very serious damage:

(a) Shriveling when more than 50 percent of the portion of kernel is severely 

shriveled;

(b) Mold when plainly visible on more than one-fourth of the surface of the portion of 

kernel in the aggregate;

(c) Discoloration of the meat when more than one-half the volume of the portion of 

kernel is severely discolored;

(d) Insect injury;

(e) Rancidity or decay; and,

(f) Shell, or any foreign material.
United States Standards for Grades of Shelled Walnuts (Juglans regia) 

(September 21, 2017)

9

§51.2295 Half kernel.

“Half kernel” means the separated half of a kernel with not more than one-eighth broken 

off.

§51.2296 Three-fourths half kernel.

“Three-fourths half kernel” means a portion of a half of a kernel which has more than 

one-eighth but not more than one-fourth broken off.