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United States Standards

for Grades of

Pistachio Nuts

in the Shell

Effective December 23, 2004
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United States Standards for Grades of Pistachio Nuts in the Shell

General

51.2540 General

Grades

51.2541 Grades

U.S. Artificially Opened

51.2542 U.S. Artificially Opened

U.S. Non-Split Grade

51.2543 U.S. Non-Split Grade

Tolerances

51.2544 Tolerances

Application of Tolerances

51.2545 Application of Tolerances

Size

51.2546 Size

Definitions

51.2547 Definitions

Average Moisture Content Determination

51.2548 Average Moisture Content Determination

Metric Conversion Table

51.2549 Metric Conversion Table

§ 51.2540 General

(a) Compliance with the provisions of these standards shall not excuse failure to comply with

provisions of applicable Federal or State laws.

(b) These standards are applicable to pistachio nuts in the shell which may be in a natural, dyed,

raw, roasted, or salted state; or in any combination thereof. 

Grades

§ 51.2541 U.S. Fancy, U.S. Extra No. 1, U.S. No. 1 And U.S. Select Grades.

"U.S. Fancy," "U.S. Extra No. 1," "U.S. No. 1," and "U.S. Select" consists of pistachio nuts in

the shell which meet the following requirements:

(a) Basic requirements:

(1) Free from:

(i) Foreign material;

(ii) Loose kernels;

(iii) Shell pieces;

(iv) Particles and dust; and,

(v) Blanks.

(b) Shells:

(1) Free from:

(i) Non-split shells; and,
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(ii) Shells not split on suture.

(2) Free from damage by:

(i) Adhering hull material;

(ii) Light stained;

(iii) Dark stained; and,

(iv) Other External (shell) defects.

(c) Kernels:

(1) Well dried, or, very well dried when specified in connection with the grade.

(2) Free from damage by:

(i) Immature kernels;

(ii) Kernel spotting; and,

(iii) Other Internal (kernel) defects.

(3) Free from serious damage by:

(i) Minor insect or vertebrate injury;

(ii) Insect damage;

(iii) Mold;

(iv) Rancidity;

(v) Decay; and,

(vi) Other Internal (kernel) defects.

(d) The nuts are of a size not less than 30/64 inch in diameter as measured by a round hole

screen.

(e) For tolerances, see §51.2544.

§ 51.2542 U.S. Artificially Opened.

"U.S. Artificially Opened" consists of artificially opened pistachio nuts in the shell which meet

the following requirements: 

(a) Basic Requirements:

(1) Free from:

(i) Foreign material;

(ii) Loose kernels;

(iii) Shell pieces;

(iv) Particles and dust; and,

(v) Blanks.

(b) Shells:

(1) Free from:

(i) Non-split shells; and,

(ii) Shells not split on suture.

(2) Free from damage by:

(i) Adhering hull material;

(ii) Light stained;

(iii) Dark stained; and,

(iv) Other External (shell) defects.

(c) Kernels;

(1) Well dried, or, very well dried when specified in connection with the grade; 

(2) Free from damage by: 
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(i) Immature kernels;

(ii) Kernel spotting; and,

(iii) Other Internal (kernel) defects. 

(3) Free from serious damage by:

(i) Minor insect or vertebrate injury;

(ii) Insect damage;

(iii) Mold;

(iv) Rancidity; 

(v) Decay; and,

(vi) Other Internal (kernel) defects.

(d) The nuts are of a size not less than 30/64 inch in diameter as measured by a round hole

screen.

(e) For Tolerances, see §51.2544.

§ 51.2543 U.S. Non-Split.

"U.S. Non-Split" consists of non-split pistachio nuts in the shell which meet the following

requirements: 

(a) Basic requirements: 

(1) Free from: 

(i) Foreign material;

(ii) Loose kernels;

(iii) Shell pieces;

(iv) Particles and dust; and, 

(v) Blanks. 

(b) Shells:

(1) Free from damage by:

(i) Adhering hull material; and,

(ii) Dark stain.

(c) Kernels:

(1) Well dried, or very well dried when specified in connection with the grade.

(2) Free from damage by:

(i) Immature kernels;

(ii) Kernel spotting; and,

(iii) Other internal (kernel) defects. 

(3) Free from serious damage by: 

(i) Minor insect or vertebrate injury; 

(ii) Insect damage;

(iii) Mold;

(iv) Rancidity; 

(v) Decay; and,

(vi) Other Internal (kernel) defects.

(d) The nuts are of a size not less than 30/64 inch in diameter as measured by a round hole

screen.

(e) For Tolerances, see §51.2544.
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§ 51.2544 Tolerances.

(a) In order to allow for variations incident to proper grading and handling, the tolerances in

Tables I, II, and III of this section are provided.

Table I - Tolerances

Factor U.S. 

Fancy

U.S. 

Extra

No. 1

U.S. 

No. 1

U.S. 

Select

U.S. 

Artificially

Opened

U.S. 

NonSplit

External (shell) Defects (tolerances

by weight)

Percent Percent Percent Percent Percent Percent

(a) Non-split and not split on suture 2 3 6 10 10 N/A

(1) Non-split included in (a) 1 2 3 4 4 N/A

(b) Adhering hull material 111 2 2 2

(c) Light stained 7 12 25 N/A N/A N/A

(1) Dark stained, included in (c) 233 3 3 3

(d) Damage by other means 1 1 2 3 10 N/A

(e) Total External Defects 9 16 N/A N/A N/A N/A

(f) Undersized (Less than 30/64 inch

in diameter): 

555 5 4 5

Table II - Tolerances

Factor U.S. 

Fancy

U.S. 

Extra

No. 1

U.S. 

No. 1

U.S. 

Select

U.S. 

Artificially

Opened

U.S. 

NonSplit

Internal (Kernel) Defects (tolerances

by weight)

Percent Percent Percent Percent Percent Percent

(a) Damage 366 6 6 6

(b) Serious Damage (Minor Insect or

Vertebrate Injury, Mold, Rancid,

Decay)

344 4 4 4

(1) Insect Damage, included in (b) 122 2 2 2

(c) Total Internal Defects 489 9 9 9
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Table III - Tolerances

Factor U.S.

Fancy

U.S. 

Extra

No. 1

U.S. 

No. 1

U.S. 

Select

U.S. 

Artificially

Opened

U.S. 

NonSplit

Other Defects (tolerances by weight) Percent Percent Percent Percent Percent Percent

(a) Shell pieces and Blanks 222 2 2 2

(1) Blanks, included in (a) 111 1 1 1

(b) Foreign material (No glass, metal

or live insects shall be permitted)

.25 .25 .25 .25 .25 .25

(c) Particles and Dust .25 .25 .25 .25 .25 .25

(d) Loose kernels 456 6 6 6

§ 51.2545 Application of tolerances.

The tolerances for the grades apply to the entire lot and shall be based on a composite sample

drawn from containers throughout the lot. Any container or group of containers which have nuts

obviously different in quality or size from those in the majority of the containers shall be

considered a separate lot and shall be sampled separately.

§ 51.2546 Size.

Nuts may be considered as meeting a size designation specified in Table IV or a range in number

of nuts per ounce, provided, the weight of 10 percent, by count, of the largest nuts in a sample

does not exceed 1.50 times the weight of 10 percent, by count, of the smallest and the average

number of nuts per ounce is not more than one-half nut above or below the extremes of the range

specified.

Table IV - Nut Size

Size Designations Average Number of Nuts Per Ounce1

Colossal Less than 18

Extra Large 18 to 20

Large 21 to 25

Medium 26 to 30

Small More than 30

1 Before Roasting

§ 51.2547 Definitions.

(a) Well dried means the kernel is firm and crisp.
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(b) Very well dried means the kernel is firm and crisp and the average moisture content of the

lot does not exceed 7.00 percent or is specified. (See §51.2548.)

(c) Loose kernels means edible kernels or kernel portions which are out of the shell and which

cannot be considered particles and dust.

(d) External (shell) defects means any blemish affecting the hard covering around the kernel. 

Such defects include, but are not limited to, non-split shells, shells not split on suture, adhering

hull material, light stained, or dark stained.

(1) Damage by external (shell) defects means any specific defect described in paragraphs (d) (1)

(i) through (v) of this section, or an equally objectionable variation of any one of these defects,

any other defect, or any combination of defects, which materially detracts from the appearance

or the edible or marketing quality of the individual shell or of the lot. (For tolerances see

§51.2544, Table I.)

(i) Non-split shells means shells are not opened or are partially opened and will not allow an

18/1000 (.018) inch thick by 1/4 (.25) inch wide gauge to slip into the opening.

(ii) Not split on suture means shells are split other than on the suture and will allow an 18/1000

(.018) inch thick by 1/4 (.25) inch wide gauge to slip into the opening.

(iii) Adhering hull material means an aggregate amount covers more than one-eighth of the total

shell surface, or when readily noticeable on dyed shells.

(iv) Light stained on raw or roasted nuts, means an aggregate amount of yellow to light brown

or light gray discoloration is noticeably contrasting with the predominate color of the shell and

affects more than one-fourth of the total shell surface or, on dyed nuts, when readily noticeable.

(v) Dark stained on raw or roasted nuts, means an aggregate amount of dark brown, dark gray or

black discoloration affects more than one-eighth of the total shell surface, or, on dyed nuts, when

readily noticeable, provided that speckled appearing stain located within the area of one-fourth

of the shell nearest the stem end shall be disregarded.

(e) Internal (kernel) defects means any blemish affecting the kernel. Such defects include, but

are not limited to evidence of insects, immature kernels, rancid kernels, mold, or decay.

(1) Damage by internal (kernel) defects means any specific defect described in paragraphs (e)

(1) (i) through (ii) of this section; or an equally objectionable variation of any one of these

defects, any other defect, or any combination of defects, which materially detracts from the

appearance or the edible or marketing quality of the individual kernel or of the lot. (For

tolerances see §51.2544, Table II.)

(i) Immature kernels are excessively thin or when a kernel fills less than three-fourths, but not

less than one-half the shell cavity.

(ii) Kernel spotting refers to dark brown or dark gray spots aggregating more than one-eighth of

the surface of the kernel.

(2) Serious damage by internal (kernel) defects means any specific defect described in

paragraphs (e) (2) (i) through (v) of this section; or an equally objectionable variation of any one

of these defects, any other defect, or any combination of defects, which seriously detracts from

the appearance or the edible or the marketing quality of the individual kernel or of the lot. (For

tolerances see §51.2544, Table II.)

(i) Minor insect or vertebrate injury means the kernel shows conspicuous evidence of feeding.

(ii) Insect damage is an insect, insect fragment, web or frass attached to the kernel. No live

insects shall be permitted.
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(iii) Mold which is readily visible on the shell or kernel.

(iv) Rancidity means the kernel is distinctly rancid to taste. Staleness of flavor shall not be

classed as rancidity.

(v) Decay means one-sixteenth or more of the kernel surface is decomposed.

(f) Other defects means defects which cannot be considered internal defects or external defects. 

Such defects include, but are not limited to shell pieces, blanks, foreign material or particles and

dust. The following shall be considered other defects. (For tolerances see

§51.2544, Table III.)

(1) Shell pieces means open in-shell nuts not containing a kernel, half shells or pieces of shell

which are loose in the sample.

(2) Blank means a non-split shell not containing a kernel or containing a kernel that fills less

than one-half the shell cavity.

(3) Foreign material means leaves, sticks, loose hulls or hull pieces, dirt, rocks, insects or insect

fragments not attached to nuts, or any substance other than pistachio shells or kernels. Glass,

metal or live insects shall not be permitted.

(4) Particles and dust means pieces of nut kernels which will pass through a 5/64 inch round

opening.

(5) Undersize means pistachio nuts in the shell which fall through a 30/64 inch round hole

screen.

§ 51.2548 Average Moisture Content Determination.

(a) Determining average moisture content of the lot is not a requirement of the grades, except

when nuts are specified as "very well dried." It may be carried out upon request in connection

with grade analysis or as a separate determination.

(b) Nuts shall be obtained from a randomly drawn composite sample. Official certification shall

be based on the air-oven method or other officially approved methods or devices. Results

obtained by methods or devices not officially approved may be reported and shall include a

description of the method or device and the owner of any equipment used.
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§ 51.2549 Metric Conversion Table

Use the following table for metric conversion:

Inches Millimeters

5/64 1.98

18/1000 0.46

1/4 6.35

30/64 11.88

Ounces Grams

1 28.35

2 56.70