United States 

Department of 

Agriculture 

Agricultural 

Marketing 

Service 

Fruit and 

Vegetable 

Programs 

Fresh Products 

Branch

Blueberries 

Shipping Point and Market 

Inspection Instructions

 

October 2002 

Previously May 

1998 

 

 
Shipping Point and Market 

Inspection Instructions for 

Blueberries 

These inspection instructions are specifically developed and designed by the 

Fresh Products Branch to assist officially licensed inspectors in the interpretation and 

application of the U.S. Standards for Grades of Blueberries, Section 51.3475. 

These instructions do not establish any substantial rule not legally authorized by 

the official grade standards. This publication supersedes any previously issued 

inspection instructions. 

Refer to General Inspection Instructions for additional information pertaining to 

date, inspection point, carrier, condition of carrier, lading, etc. not covered in these 

instructions. (Reference to "General Inspection Instructions" in all Fresh Products 

Branch publications refers to any one, or all of the following - General Shipping Point 

Inspection Instructions, General Market Inspection Instructions, or Fresh Fruit and 

Vegetable Certificate Writing Handbooks.) 

Any portion of these instructions beginning with a section number such as 51.--- 

and followed with bold print is material copied directly from the U.S. standards. The 

U.S. Standards for Grades Blueberries are printed in the appendix of this instruction. All 

of the U.S. standards are available on the Internet under the USDA homepage. 

This replaces instructions dated June 1966. 

Previously May 1998

October 2002 

This publication may be duplicated without authorization from USDA. 
ii

Factors noted with (Q) are considered quality only. Factors noted with (C) are 

considered condition at market. Factors noted with (Q or C) may be quality or condition 

depending on the circumstances. 

TABLE OF CONTENTS 

GENERAL ....................................................................................................................... 1

REPRESENTATIVE SAMPLING .................................................................................... 1

SIZE OF SAMPLE ............................................................................................................ 1

NUMBER OF SAMPLES .................................................................................................... 2

TOLERANCES AND APPLICATION OF TOLERANCES .............................................. 2

APPLICATION OF TOLERANCES ........................................................................................ 3

NOTESHEET AND CERTIFICATE ................................................................................. 4

PRODUCT ...................................................................................................................... 5

NUMBER/TYPE OF CONTAINERS ...................................................................................... 5

BRANDS/MARKINGS........................................................................................................ 5

ORIGIN .......................................................................................................................... 6

CONDITION OF PACK ................................................................................................... 6

TEMPERATURE OF PRODUCT .................................................................................... 6

SIZE ................................................................................................................................ 7

QUALITY AND CONDITION ........................................................................................... 8

ATTACHED STEMS (Q) .................................................................................................... 8

BROKEN SKINS (Q OR C) ................................................................................................ 9

CLEAN (Q) ................................................................................................................... 10

CLUSTERS (Q) ............................................................................................................. 10

CRUSHED, SPLIT, OR LEAKING (C) ................................................................................. 11

FIRMNESS (C) .............................................................................................................. 12

GREEN BERRIES (Q) .................................................................................................... 12

INSECTS OR INSECT INJURY (Q OR C) ............................................................................ 13

MUMMIFIED BERRIES (Q) .............................................................................................. 13

SCARS (Q) .................................................................................................................. 14

SHRIVELING (C) ........................................................................................................... 14

SIMILAR VARIETAL CHARACTERISTICS (Q) ...................................................................... 15

WELL COLORED (Q) ..................................................................................................... 15

WET (C) ...................................................................................................................... 15

DECAY OR MOLD (C) .................................................................................................... 16

APPENDIX I – INSPECTION OF “WILD” BLUEBERRIES IN THE MARKET ............. 17
iii

APPENDIX II – MAGGOT TEST ................................................................................... 18

APPENDIX III – U. S. GRADE STANDARDS ............................................................... 20

UNITED STATES STANDARDS FOR GRADES OF BLUEBERRIES ........................................... 20

APPENDIX IV – EXAMPLES ........................................................................................ 23

EXAMPLE 1 - INSPECTION NOTESHEET ........................................................................... 23

EXAMPLE 1 - INSPECTION CERTIFICATE .......................................................................... 24

EXAMPLE 2 - INSPECTION NOTESHEET ........................................................................... 25

EXAMPLE 2 - INSPECTION CERTIFICATE .......................................................................... 26

EXAMPLE 3A - INSPECTION NOTESHEET ......................................................................... 27

EXAMPLE 3B - INSPECTION NOTESHEET ......................................................................... 28

EXAMPLE 3A - INSPECTION SCORESHEET....................................................................... 29

EXAMPLE 3B - INSPECTION SCORESHEET....................................................................... 30

EXAMPLE 3A - INSPECTION CERTIFICATE ....................................................................... 31

EXAMPLE 3B - INSPECTION CERTIFICATE ....................................................................... 32

EXAMPLE 4 - INSPECTION NOTESHEET ........................................................................... 33

EXAMPLE 4 - INSPECTION SCORESHEET ......................................................................... 34

EXAMPLE 4 - INSPECTION CERTIFICATE .......................................................................... 35
iv
1

GENERAL 

The U.S. Standards for Grades of Blueberries applies to blueberries produced 

under cultivation; varieties of the highbush and rabbiteye. The standards do not

apply to lowbush or "wild" blueberries. 

Lowbush or "wild" blueberries are generally grown in the State of Maine and 

parts of Canada. The lowbush (wild) blueberries may be distinguished from the 

highbush (cultivated) blueberries, in that the plants are usually 6 to 18 inches high 

and spread into large colonies by means of underground shoots called rhizomes. 

The lowbush (wild) berries are generally smaller in size than the cultivated berries 

and the lowbush berries may vary in color. 

Containers that are marked "wild" blueberries, shall be restricted to condition 

only inspections. Inspection procedures for "wild" blueberries shall be the same as 

described in the following pages for "cultivated" blueberries. The condition factors 

shall be described and not reported as damage or serious damage. The lot may be 

inspected on the basis of the Maine Marketing Order at applicant's request. A copy 

of the Maine Marketing Order may be obtained from the Maine Department of 

Agriculture. (See Appendix I) 

REPRESENTATIVE SAMPLING 

The importance of obtaining representative samples cannot be over 

emphasized. Accurate certification is possible only if the samples examined are 

truly representative of the entire lot or accessible portion. All portions of a lot or load 

shall receive the same attention in sampling regardless of the difficulty involved in 

reaching all layers or parts of a load. 

Size of Sample 

The tolerances in the U.S. Standards for Grades of Blueberries are 

determined on the basis of count. Before an inspector opens a container that is to 

be sampled, the inspector shall predetermine from what area in the container to take 

the sample. A minimum of 100 berries or the entire container (when less than 100 

berries) shall be examined. Whenever a load or lot is out of grade because defects 

in a sample exceed the sample tolerance or lot tolerance, at least double (200 

berries) or the entire container (when less than 200 berries) shall be examined. 

When two or more berries are attached together by stems they are to be 

counted as one berry when obtaining the sample. 

When the size of the samples are not uniform, the percentage shall be 

determined for each sample. All percentages must be totaled and divided by the 
2

number of samples examined, in order to determine the average percentages for the 

lot. 

When the size of the samples are uniform, the total number of defects shall 

be divided by the total number blueberries sampled. 

Number of Samples 

As a general rule a minimum of 1% of the lot must be examined. For lots of 

less than 300 packages a minimum of 3 samples must be examined. It is the 

inspector's responsibility to examine additional representative samples when the 

quality, condition, or size in samples is decidedly different to ensure an accurate 

description of the lot. 

As a guide, for a full load of blueberries the inspector shall sample the 

equivalent of two master containers and obtain one sample from each master 

container. For example, the blueberries are packed in 12 - 1-pint flats. The 

inspector shall sample a minimum of 24 - 1-pint containers, and obtain one pint from 

24 different flats.

TOLERANCES AND APPLICATION OF TOLERANCES 

§51.3478 Tolerances...(a) For defects at shipping point. Ten 

percent for blueberries which have attached stems. Additionally, 

not more than 8 percent of the blueberries may be below the 

remaining requirements of the grade: Provided, that included in 

this amount not more than 4 percent shall be allowed for defects 

causing serious damage, including in this latter amount not more 

than 1 percent for blueberries which are affected by mold or 

decay. 

(b) For defects en route or at destination. Ten percent for 

blueberries which have attached stems. Additionally, not more 

than 12 percent of the blueberries may be below the remaining 

requirements of the grade: Provided, that included in this amount 

not more than the following percentages shall be allowed for 

defects listed: (1) 8 percent for blueberries which fail to meet the 

requirements for this grade because of permanent defects; or, (2) 

6 percent for blueberries which are seriously damaged, including 

therein not more than 4 percent for blueberries which are 

seriously damaged by permanent defects and not more than 2 

percent for blueberries which are affected by mold or decay. 
3

(c) Off-size: When size is designated according to one or more of 

the size classifications in §51.3477, not more than 10 percent of 

the samples in any lot or one sample, whichever is the greater 

number, may fail to meet the range in count specified. 

SUMMARY OF TOLERANCES 

FACTORS At Shipping Point1 En Route or 

At Destination 

A. Attached Stems 10% 10% 

B. Defects other than 

 attached stems 

8% 12% 

1. Damage by 

 Permanent Defects 

(included in "B") 

---- 8% 

2. Serious Damage 

(included in "B") 

4% 6% 

a. Serious Damage by 

 Permanent Defects 

(included in "1" and "2") 

---- 4% 

b. Mold or Decay 

(included in "2") 

1% 2% 

1Shipping point, as used in these standards, means the point of origin of the shipment in the producing area or at port of 

loading for ship stores or overseas shipment, or, in the case of shipments from outside the continental United States, the port

of entry into the United States. 

Off-size. Not more than 10% of the samples in any lot or one sample, 

whichever is greater, may fail to meet the range in count specified. 

Note: "Permanent" and "Quality" defects are used interchangeably. 

Application of Tolerances 

§51.3479 Application of Tolerances...Individual samples are 

subject to the following limitations: Provided, that the averages 

for the entire lot are within the tolerances specified for the grade: 

(a) For tolerances of 10 percent or more, individual samples may 

contain not more than one and one-half times the specified 

tolerances. 
4

(b) For a tolerance of less than 10 percent, individual samples 

may contain not more than double the specified tolerance. 

SUMMARY OF APPLICATION OF TOLERANCES 

FACTORS At Shipping Point1 En Route or 

At Destination 

A. Attached Stems 15% 15% 

B. Defects other than 

 attached stems 

16% 18% 

1. Damage by 

 Permanent Defects 

(included in "B") 

---- 16% 

2. Serious Damage 

(included in "B") 

8% 12% 

a. Serious Damage by 

 Permanent Defects 

(included in "1" and "2") 

---- 8% 

b. Mold or Decay 

(included in "2") 

2% 4% 

1Shipping point, as used in these standards, means the point of origin of the shipment in the producing area or at port of 

loading for ship stores or overseas shipment, or, in the case of shipments from outside the continental United States, the port

of entry into the United States. 

Note: "Permanent" and "Quality" defects are used interchangeably. 

NOTESHEET AND CERTIFICATE 

Entries on the notesheet and certificate must be kept in a legible and accurate 

manner. It is mandatory that all information which appears on the certificate be 

supported by information on the notesheet. It is the responsibility of the inspector to 

ensure that all information is properly recorded. Notations shall be recorded so that 

anyone familiar with inspection procedures can interpret them and write a certificate. 

Also remember that notesheets and certificates are prima facie evidence and must 

be able to withstand legal scrutiny. 

Detail instructions pertaining to date, inspection point, place of inspection, 

type of carrier, lading, etc., which are not covered by these instructions may be 
5

found in the General Inspection Instructions. Additional information and instructions 

may be given by your supervisor. 

Product 

"Blueberries" shall be used to describe this commodity in the “Product” 

heading. Type may be reported in conjunction with “Blueberries” or may be reported 

in the “Product/Variety” section on the shipping point inspection certificates or in the 

“Lot ID” section on market notesheet and certificate. 

When containers are marked with the name of the variety, it shall be quoted 

rather than a positive statement, as to the variety. If the applicant requests variety 

certification only, the inspection shall be declined with an explanation that the law 

under which the Inspection Service operates does not cover variety. 

Number/Type of Containers 

The number of containers shall always be reported. In the market and at 

shipping point locations for stationary lot certification, the inspector shall always 

verify the container count provided by the applicant for each lot and report it as the 

“inspector’s count.” If the number of containers available for inspection does not 

match the application it is the inspector’s responsibility to confirm that the amount 

presented for inspection constitutes the lot. If an accurate count cannot be 

determined the inspector may report the count at someone else’s authority. 

However, the reason for doing so must be reported on the notesheet (e.g., 

numerous pallets with mixed product.) 

At shipping point locations for "days-run" certification the applicant generally 

provides a manifest for count and it is acceptable to use this for the number of 

containers. 

Blueberries are most commonly packed in film wrapped consumer packages 

or plastic, "clam-shell" type containers within master containers. Occasionally, 

blueberries may be packed in bulk 5 or 10 pound cartons. The type of container 

shall always be reported under this heading. 

Brands/Markings 

The brand, variety, size, count, grade, weight, point of origin and other 

important information appearing on the container should be reported on the 

notesheet in the "Brands/Markings" section. Only the brand name and other key 

markings necessary to properly identify the lot for certification should appear in this 

section on the certificate. 
6

Origin 

The inspector should not make a positive statement on their own authority, 

but when container markings list the state or country of origin, it should be quoted in 

the appropriate space on the notesheet and the certificate. If origin is not marked, it 

is the inspectors responsibility to make an effort to obtain this information for the 

applicant. This policy is necessary because some firms may use one mark on the 

same product packed in several states. The inspector can certify only to the marks 

and has no means of verifying what state or country the blueberries are grown. 

CONDITION OF PACK 

The following terms shall be used to describe pack: 

Excessively filled: This means that the containers are filled over 3/4 inches 

above the top of the rim of the container and some berries are bruised or crushed. 

Well filled: Berries are at least 1/4 and as much as 3/4 inch above rim of 

container. 

Fairly well filled: The containers are at least level full. 

Slightly slack: When berries are slightly below top of container. 

Slack: When berries are decidedly below the top of the container. Always 

report "slack" in fractions of inch increments. 

TEMPERATURE OF PRODUCT 

Inspectors would not normally determine or report temperatures at shipping 

point. However, due to the importance of the pulp temperature of fresh fruits and 

vegetables when in transit or at destination, it is essential that the inspector 

accurately determine and report the temperature or range in temperatures on each 

lot. Pulp temperature should be reported regardless of the location of the product, 

whether in the carrier, warehouse, or stacked on the platform. Remember to precool the thermometer in order to obtain true readings. Report all temperatures to the 

nearest whole degree. 

A minimum of three temperatures for each lot must be taken and recorded on 

the notesheet. More temperatures must be taken if the lot is abnormally cold, 

heated, or there is a specific request for temperature, and these must be reported in 

greater detail specifying location in lot or load. 
7

SIZE 

§51.3475 General...(b) Because of the size difference between 

varieties and the difference in size preference in various markets, 

there are no size requirements in the grade. Therefore, size will 

not be determined unless specifically requested by the applicant. 

If requested, size may be specified as provided in §51.3477. 

§51.3477 Size classifications...The following size classifications 

may be used in specifying size of blueberries: (a) Extra Large. 

Less than 90 berries per cup; (b) Large. 90 to 129 berries per cup; 

(c) Medium. 130 to 189 berries per cup; and, (d) Small. 190 to 250 

berries per cup. (e) For tolerances see §51.3478. 

Cup equals 237 ml, 1/2 pint, or 2 gills. 

Size is not part of the basic requirements for the grade. Therefore, a lot of 

blueberries could fail to meet size requirements and still meet the requirements for 

the grade. 

Size will not be determined unless specifically requested by the 

applicant. The applicant may specify the size in terms of small, medium, large, 

extra large or any combination thereof; small to medium, small to large, etc. or in 

terms of number of berries per cup; 100 to 120 berries per cup. If the applicant 

requests that size be determined, the inspector must use a cup container. 

A cup container used for size determination is equivalent to 237 ml, 

1/2 pint, or 2 gills. These containers may be obtained from a hardware or grocery 

store. Fill the cup level full; meaning the berries in the cup should not be heaping 

over the rim, and no open spaces below the rim. The inspector must then count the 

number of berries in a cup for each sample. The number of berries found per cup 

will indicate the size of berries; for example: 1 cup = 132 berries, this means that 

they are medium blueberries for that sample. Determine the count for each sample 

and report the size either by size classification or count. 

If a size or sizes are marked on the container or specifically designated by the 

applicant, the inspector must size the berries according to the size(s) specified. If 

more than 10 percent of the samples in any lot or one sample, whichever is greater, 

fails to meet the range in count specified, the load or lot will fail to meet size. 

When size is marked on the container, report the size in conjunction with 

the grade. For example: "U.S. No. 1 Large" OR "Fails to meet U.S. No. 1 Large 

account _____." Additionally, report the overall size in the “Description of Product” 

section on shipping point certificates and in the “Other” section on market 

certificates. 
8

When the applicant specifies a particular size, then the inspector will 

determine whether the lot meets the specified size. For example: The applicant 

requests a "Small to Medium" size. Report in the “Grade” section: "U.S. No. 1" OR 

"Fails to grade U.S. No. 1 account _____." Report “Description Of Product” section 

on the shipping point certificate or in the “Other” section on market the range and 

whether it meets or fails to meet size as specified. For example: "Range 127 to 255 

berries per cup, fails to meet size as specified" OR "Range 134 to 210 berries per 

cup, meets size as specified. " Also, report under “Remarks”: "Size based on Small 

to Medium size, at applicant’s request." 

If size is not marked on the container and the applicant does not request size, 

state on the notesheet, "Size not determined." 

QUALITY AND CONDITION 

Statements pertaining to freshness, maturity, shape, color, the amount and 

type of defects, and the amount of decay are shown under the appropriate headings. 

Factors noted with (Q) are considered as QUALITY only (Quality, sometimes 

referred to as "permanent" defects, means defects which do not change during 

storage or shipment (shape, scars, etc.). 

 

Factors noted with (C) shall be reported as CONDITION on market 

certificates. (Condition defects are defects which are subject to change during 

shipment or storage, including but not limited to bruising, discoloration, shriveling 

and decay). 

Those factors noted with (Q or C) may be considered as QUALITY or 

CONDITION, depending on the circumstances. 

Attached Stems (Q) 

Blueberries are attached to the bushes by their stems. Often times while 

harvesting the stem adheres to the blueberry and the stem remains there as they 

are packed. Some varieties are more susceptible to attached stems than other 

varieties. The stem may vary in length from 1/8 of an inch to more than 1/2 inch in 

length. 

Blueberries with attached stems are a "free from" defect; any length of stem is 

scored as a quality defect against the separate 10 percent tolerance for attached 

stems. Do not report as serious damage. 

§51.3478 Tolerances...Ten percent for blueberries which have 

attached stems. 
9

Blueberries may be scored twice if affected by attached stems and another 

defect because there are separate tolerances for attached stems and "other" 

defects. At shipping point, there is a 10% tolerance for attached stems and an 8% 

total tolerance for other defects, including 4% for serious damage, including 1% for 

mold or decay. At market, there is a 10% tolerance for attached stems and a 12% 

total tolerance for other defects, including 8% permanent defects, including 6% for 

serious damage, including 4% for serious damage by permanent defects, including 

2% for mold or decay. 

For example: If a berry had an attached stem and a scoreable scar, it would 

be scored twice, once for the attached stem and once for the scar. If the berry had 

an attached stem and decay, it would be scored twice, once for the attached stem 

and once for decay (provided that the inspector could determine that there was an 

attached stem). 

If the berry is scored twice under separate tolerances, the defects shall be 

cross referenced on the certificate. For example: "6% defects, including 2% above 

as attached stems." 

If there are two berries attached together by stems, with no defects on the 

berries, score as one entity (one berry), as an attached stem. If the two berries also 

have defects, score the berry once for attached stem and once for the other 

tolerance most affected. If there are three or more capstems with at least one berry 

attached it will be treated as a "cluster" (see section on "Clusters"). 

Broken Skins (Q or C) 

Broken skins are generally caused by stems adhering to the berry and when 

they are pulled out, cause a tear in the skin; often called a pulled stem. 

Occasionally, berries may receive a broken skin when a berry with a stem attached 

punctures the wall of another berry or they may be caused by bird pecks. 

At market, broken skins that are "fresh" or not well healed will be scored as 

a condition factor against the serious damage tolerance. Broken skins that are 

"old" or well healed will be scored as a quality factor when it is readily noticeable, 

except for an allowable area within a 1/8 inch circle centered at the stem scar. 

Score the quality defect against the tolerance for damage by permanent defects. 

At shipping point, broken skins that are not well healed will be scored 

against the serious damage tolerance. Broken skins that are well healed will be 

scored as damage against the total tolerance for the grade when readily noticeable, 

except for an allowable area within a 1/8 inch circle centered at the stem scar. 
10

§51.3484 Damage...(d) Broken skins when not well healed or when 

well healed and readily noticeable, except for an allowable area 

within a 1/8 inch (3.2 mm) circle centered at the stem scar; 

§51.3485 Serious Damage...(g) Broken skins when not well 

healed. 

To determine whether a blueberry is damaged by a "pulled stem" (reported as 

"broken skin"), place the 1/8 inch circle from the Plexiglas area gauge approximately 

over the center of the stem scar of the blueberry. If any amount of broken skin is 

outside of that 1/8 inch circle, the blueberry shall be scored as damage by broken 

skins. 

Clean (Q) 

§51.3481 Definitions..."Clean" means that the individual berry is 

practically free from dirt, frass, or other foreign material. 

Blueberries are generally clean due to the fact that they are grown on bushes 

above the ground and may be washed before packing. However, leaves and other 

foreign material may be encountered. Therefore, if the berries show only a slight 

amount of dirt or an occasional leaf, the lot will still be considered clean. However, if 

the amount of dirt, frass or other foreign material is such that it is readily apparent 

and objectionable, it shall be scored as "not clean." At shipping point, score 

against the total tolerance for the grade. At market, score against the tolerance for 

damage by permanent defects. 

Freshly harvested berries normally have a "bloom." Bloom is a white frosty 

looking film which can be easily removed from a berry by handling. It is felt that 

bloom indicates good quality and is very eye appealing. However, with more 

growers harvesting blueberries mechanically, and using mechanical sorting and 

grading equipment, bloom is not as evident as it once was. If requested by applicant 

to report the presence or absence of bloom it will be permissible to do so, but do not 

score it as a defect; report it at applicant’s request, not affecting grade. If not 

requested, make no mention on the certificate. 

Clusters (Q) 

Blueberries are attached to the bushes by stems and often grow in "clusters." 

During harvesting, the stem adheres to the blueberry and the berries are picked as a 

"cluster" rather than individual berries. If the blueberries are field packed and placed 

directly into their marketing containers, the clusters of berries will be seen more 

frequently than those blueberries that are harvested and transported to a packing 

line. The berries from a packing line are normally sorted for quality and most of the 

clusters will be eliminated. 
11

Clusters are a "free from" defect; any amount is scoreable. Clusters are 

considered a quality defect. At shipping point, score as damage against the total 

tolerance for the grade. At market, score against the tolerance for damage by 

permanent defects. 

§51.3484 Damage...(b) Clusters when there are three or more 

joined capstems with at least one berry attached. 

"Clusters" are treated as a single berry (entity, unit), even though there may 

be more than one berry attached to the cluster. Report this defect as "clusters" and 

score as such. At shipping point, if one or more of the berries are affected by a 

defect of a more serious nature (decay, mold, crushed, split, or other serious 

damage defects), score it as one berry (entity, unit) as a serious defect (decay, 

mold, etc.) and not a cluster. At market, if one or more of the berries are affected 

by a condition defect (decay, mold, crushed, split, etc.), score it as a berry (entity, 

unit) against the condition defect (decay, mold, etc.) and as a cluster. These defects 

shall be cross referenced on the certificate. For example: "4% decay, including 2% 

reported above as quality defect (clusters)." 

If there are two berries attached together by stems, with no defects on the 

berries, score as one entity (one berry), as an attached stem. If the two berries also 

have defects, score the berry once for attached stem and once for the other 

tolerance most affected. If there are three or more capstems with at least one berry 

attached it will be treated as a "cluster." 

Crushed, Split, or Leaking (C) 

Blueberries may be crushed, split or leaking due to either rough handling 

while harvesting, packing or shipping; or the blueberries are ripe and have been held 

in storage for too long. 

Mechanical harvesters could cause blueberries to be crushed, split or leaking. 

These berries are generally eliminated when they are packed on a mechanized 

packing line. However, the packing line could cause berries to be crushed or split. If 

the blueberries are field packed and placed directly into their marketing containers, 

crushed, split or leaking berries may be at the bottom of the container. If there are 

ripe berries on the bottom of the containers, they too may become split, crushed or 

leaking due to the weight of the other berries. A large amount of rain prior to harvest 

or excessive heat could cause blueberries to split and leak. Finally, rough handling 

due to crushed boxes, shifted loads, etc. will cause crushed, split or leaking berries. 

§51.3485 Serious Damage...(d) Crushed, split or leaking berries. 

Score crushed, split or leaking berries as a condition factor against the 

restricted tolerance for serious damage. 
12

Firmness (C) 

Firmness should be described with care as buyers and shippers may depend 

upon such descriptions to determine the condition in which the fruit arrived and the 

length of time it will remain in good condition. 

The following terms shall be used in describing the degree of firmness of 

blueberries: 

Firm - means that the berry yields very slightly to moderate pressure. 

Ripe - means that the berry yields very readily to slight pressure. The flesh is 

firm, not soft or mushy and has reached the best eating condition. This condition 

meets the grade requirements. 

Overripe - this condition does not meet the grade requirements. 

§51.3483 Definitions..."Overripe" means that the individual berry 

is dead ripe, the flesh is soft and mushy, and past commercial 

utility. 

§51.3485 Serious damage...(c) Overripe berries. 

The requirement for the grade is "not overripe." Overripe berries are a 

condition defect, scored as serious damage against the restricted tolerance for 

serious damage. Do not confuse overripe berries with berries that are "ripe." Ripe 

berries will yield readily to slight pressure over the whole berry, but the flesh of the 

berry will still be firm. Only consider the berry as "overripe" when the berry is soft 

and the flesh is soft and mushy – past the best eating condition. 

Green Berries (Q) 

While blueberries are being harvested, various colors of berries may be on 

the same bush at the same time. Green berries may inadvertently be harvested at 

the same time that the blue, bluish-purple, purple, bluish-red, or bluish-black berries 

are harvested. Generally the green berries are sorted out before packing, unless 

they are harvested into packing containers, in which case they are not sorted and 

green berries may be present in the container. 

§51.3484 Damage...(f) Green berries when one-half or more of the 

berry is green. 

If the berry has one-half or more of its surface with green color, score as 

damage, and report as "green berries." At shipping point, score against the total 

tolerance for the grade. At market, score against the tolerance for damage by 

permanent defects. If the berry has more than one-half of its surface that is not blue, 
13

bluish-purple, purple, bluish-red, or bluish-black in color, report as "not well 

colored." At shipping point, score against the total tolerance for the grade. At 

market, score against the tolerance for damage by permanent defects. Do not 

score as serious damage. (See "Well Colored" section.) 

Insects or Insect Injury (Q or C) 

Various types of insects may affect blueberries. Regardless of the type of 

insect, if there is any visible evidence of the insect, insect larva, feeding, webbing or 

frass, it will be scored as serious damage against the serious damage tolerance (at 

market, score as serious damage by permanent defects tolerance when a quality 

factor [see below]). 

§51.3485 Serious Damage...(f) Insects or when there is any visible 

evidence of the presence of insects, including but not limited to 

an insect, the insect larva, feeding, webbing or frass. 

At market, if the insects are live or there is evidence of fresh frass or feeding 

that occurred during transit, treat as a condition factor. If the insects are dead or 

the insect feeding or frass is old, treat as a quality factor. If both live and dead 

insects are present, treat as a condition factor. 

Various regions in the United States are susceptible to an insect called 

Blueberry Maggot. This insect is difficult to see with the naked eye and may require 

a special test to detect it. If the applicant specifically requests this test see the 

procedures in Appendix II for details. 

Mummified Berries (Q) 

While blueberries are being harvested, various stages of maturity may be on 

the same bush, including mummified berries. Mummified berries are those berries 

that have been affected by a fungus; the berry dries up, withers, or shrinks. 

Mummified berries may inadvertently be harvested at the same time that the other 

berries are harvested. Generally the mummified berries are sorted out before 

packing, unless they are harvested directly into marketing containers, in which case 

they are not sorted and may be in the container. 

§51.3485 Serious Damage...(e) Mummified berries when the 

individual berry is dried up, withered or shrunken. 

Score mummified berries as a quality factor. At shipping point, score 

against the restricted tolerance for serious damage. At market, score against the 

serious damage by permanent defects tolerance. 
14

Do not confuse mummified berries with shriveled berries. Shriveling generally 

affects a specific area of the blueberry. Mummified berries are different than 

shriveled berries in that the shriveling, withering, drying, etc. affects the entire berry, 

whereas shriveling usually affects only a portion of the berry. (See "Shriveling" 

section.) 

Scars (Q) 

Scars generally consist of brownish corky tissue formed on the surface of the 

blueberry. Scars are caused when the blueberry is injured by the branches of the 

blueberry bush while it is growing and the injury heals over resulting in a scar. 

§51.3484 Damage...(e) Scars when affecting more than 20 percent 

of the surface of the individual berry; 

§51.3485 Serious damage...(h) Scars when affecting more than 50 

percent of the surface of the individual berry. 

At market, score as damage by scars against the 8% tolerance for damage 

by permanent defects. When scored as serious damage by scars score it against 

the 4% tolerance for serious damage by permanent defects. 

At shipping point, score damage by scars against the total tolerance for the 

grade. For serious damage by scars score it against the serious damage tolerance. 

Shriveling (C) 

Shriveling or wrinkling generally affects a specific area and not the entire 

surface of the berry. If the entire berry is withered, shrunken and dried up it may be 

considered mummified and not shriveled (see "mummified berries" section). 

Mummified berries are those berries that have been affected by a fungus; the berries 

are dried up, withered, or shrunken. 

§51.3484 Damage...(c) Shriveling when the wrinkling is readily 

noticeable. 

Score damage by shriveling when readily noticeable. "Readily noticeable" 

means that when inspecting blueberries and rolling the blueberries around on a flat 

surface or passing them back and forth in your hands, the inspector observes 

shriveling or wrinkling on a berry. However, if the inspector has to closely examine 

or "study" the berry, there is not a sufficient amount of shriveling and shall not be 

scored as a defect. 

Score shriveling as serious damage when seriously detracting from the 

appearance of the berry. 
15

Similar Varietal Characteristics (Q) 

§51.3480 Definitions..."Similar varietal characteristics" means that 

the berries are similar in color and shape. 

The Inspection Service does not certify variety. When variety is in question, 

the inspector shall inform interested parties that only type may be certified. It may 

also be pointed out that when type is a factor in a load or lot of blueberries, such as 

distinctly different colors or shapes, it will be considered a defect. The defect 

shall be reported as dissimilar varietal characteristics and score as a quality 

defect. At shipping point, score against the total tolerance for the grade. At 

market, score against the tolerance for damage by permanent defects. 

Do not confuse this with green berries or berries that are not well colored. 

See sections for Well Colored and Green Berries for further descriptions. 

Well Colored (Q) 

Blueberries, when growing on the bush, begin as green berries. As they grow 

and develop they start to turn color; usually a pink to red color at first, which 

becomes blue, bluish-purple, purple or bluish-black, depending upon the variety. 

§51.3482 Definitions..."Well colored" means that more than onehalf of the surface of the individual berry is blue, bluish-purple, 

purple, bluish-red, or bluish-black. 

When more than one-half of the berry is not blue, bluish-purple, purple, 

bluish-red, or bluish-black in color, report as "not well colored. " At shipping point,

score against the total tolerance for the grade. At market, score against the 

tolerance for damage by permanent defects. Do not score as serious damage. 

§51.3484 Damage...(f) Green berries when one-half or more of the 

berry is green. 

If the berry has one-half or more of its surface with green color score as 

damage, and report as "green berries." At shipping point, score against the total 

tolerance for the grade. At market, score against the tolerance for damage by 

permanent defects (see "Green Berries" section). Do not score as serious damage. 

Wet (C) 

Blueberries may become wet due to condensation by taking berries from a 

cool storage into warm, humid outside air, or when unloaded from a refrigerated 

trailer during hot, humid weather or rain. Do not score blueberries that are wet from 

condensation. 
16

Blueberries that are wet from juice due to crushed, leaking or decayed berries 

will be sticky because of the sugar content of the berry. Score these berries as 

damage. 

§51.3484 Damage...(a) Wet berries when the individual berry is 

wet from juice from crushed, leaking, or decayed berries, but not 

due to condensation. 

Score as a condition factor against the total tolerance for the grade. Report 

as “Wet Berries.” 

Decay or Mold (C) 

Decay or mold are "free from" defects; any amount is scored as serious 

damage against the restricted tolerance for mold or decay. 

§51.3485 Serious damage...(a) decay; 

§51.3485 Serious damage...(b) moldy berries. 

The most common types of decay that affect blueberries include, Gray Mold 

Rot, Alternaria Rot, and Rhizopus Rot. However, inspectors do not have to identify 

the type of decay. At market, a description of the stages of decay is all that is 

needed; early, moderate or advanced stages. 
17

Appendix I – Inspection of “Wild” Blueberries in the 

Market 

Maine is apparently the only place in the country currently packing and 

inspecting "wild" blueberries. Inspection at shipping point is based on a Maine 

marketing order. Therefore, when containers are marked "wild" blueberries the U.S. 

Standards for Grades of Blueberries does not apply. The U.S. standards apply to 

varieties of the highbush and rabbiteye. Wild blueberries are a lowbush variety. 

When containers are marked "wild" blueberries the inspection shall be 

restricted to condition only or inspected on the basis of the Maine marketing order at 

applicant’s request. When the inspection is restricted to condition only, the 

condition factors shall be described and reported only in the "AVERAGE DEFECTS" 

column on the FV-300; do not report damage or serious damage. The inspection 

procedures previously described shall be used for condition only inspections. When 

the inspection is requested to be based on the Maine Marketing Order, copies may 

be obtained from Maine Department of Agriculture. 
18

Appendix II – Maggot Test 

The maggot test will only be done at applicant’s request, if certification is required 

by a State or local law, and if the inspection office has the necessary equipment. This 

test is entirely separate from determining the quality and condition of the lot, as 

previously outlined in these inspection instructions. For example: A lot could meet 

quality and condition requirements, but would fail to grade U.S. No. 1 account of the 

maggot test. 

While this procedure is not specifically detailed in the grade standards, the 

tolerance for the number of maggots found in the "maggot test" is based on the 

definition for serious damage by insects against the serious damage tolerance. 

Therefore, if 4 or less maggots are found in the composite sample, the lot would meet 

the requirements for the U.S. No. 1 grade. However, if 5 or more maggots are found in 

the composite sample, the lot would fail to meet the requirements for the U.S. No. 1 

grade. 

Maggots will be considered a quality factor at shipping point. However, due to 

the process of "cooking" it is difficult to tell whether the maggots were alive before 

cooking, therefore at the market score maggots as a condition factor. 

Grade statements shall indicate that the lot failed account of maggots. For 

example: At shipping point, "Fails to grade U.S. No. 1 account quality (maggots)." At 

market, "Fails to grade U.S. No. 1 account condition (maggots)." 

Remember to state under remarks, for both shipping point and market 

certificates, "Maggot test performed at applicant’s request." 

Necessary Equipment

 Container for cooking the sample. 

 Heating apparatus for cooking the sample. 

 Round pan 2 to 3 inches in depth, 12 inches in diameter (bottom painted 

black). 

 1/8 to1/4 inch mesh sieve, approximately 6 inches in diameter by 3 inches in 

depth. 

 Fresh water available at all times. 

 Trash can. 
19

Procedure

Weigh or measure out a composite one pound sample from the containers that 

were sampled. Put the one pound of blueberries in the container for cooking and mash 

them, making a thin liquid by adding fresh water. Heat the container until the 

blueberries have reached a hot “rolling” boil. Pour contents through sieve into a pan 

about 12 inches in diameter and 2 inches deep, having a black bottom. Before 

removing sieve from pan, wash skins and pulp with fresh water, almost filling pan. 

Empty skins and pulp into trash can. It will be necessary to let the pan stand a while as 

the contents at first will be cloudy. When the contents clear, slowly pour water and 

some of the finer pulp out of the pan until there is about one-half inch of water left. 

Repeat this process by adding fresh water and pouring off until solution in pan is 

practically clear. Then the pan should be placed on a flat surface. Stir the solution in a 

circular motion. If maggots are present, they will settle toward the center of the pan and 

will be readily apparent as small white objects against the black surface of the pan. 
20

Appendix III – U. S. Grade Standards 

United States Standards for Grades of Blueberries 

Effective March 20, 1995 

General

51.3475 General. 

Grade

51.3476 U.S. No. 1. 

Size Classifications

51.3477 Size classifications. 

Tolerances

51.3478 Tolerances. 

Application of Tolerances

51.3479 Application of tolerances. 

Definitions

51.3480 Similar varietal characteristics. 

51.3481 Clean. 

51.3482 Well colored. 

51.3483 Overripe. 

51.3484 Damage. 

51.3485 Serious damage. 

General

§51.3475 General.

(a) These standards apply only to selected and hybrid varieties of the highbush (Vaccinium australe 

Small and Vaccinium corymbosum L.) and rabbiteye (Vaccinium ashei Reade) blueberries produced 

under cultivation, but not to other species of the genus Vaccinium nor to the true huckleberries of the 

genus Gaylussacia. 

(b) Because of the size differences between varieties and the difference in size preference in various 

markets, there are no size requirements in the grade. Therefore, size will not be determined unless 

specifically requested by the applicant. If requested, size may be specified as provided in §51.3477. 

Grade

§51.3476 U.S. No. 1.

"U.S. No. 1" consists of blueberries which meet the following requirements: 

(a) Basic Requirements: 

(1) Similar varietal characteristics; 

(2) Clean; 

(3) Well colored; 

(4) Not overripe; 

(5) Not crushed, split, or leaking; and, 

(6) Not wet. 

(b) Free From: 

(1) Attached stems; 

(2) Mold; 

(3) Decay; 

(4) Insects or when there is visible evidence of the presence of insects; 

(5) Mummified berries; and, 

(6) Clusters. 

(c) Free From Damage Caused By: 

(1) Shriveling; 

(2) Broken skins; 

(3) Scars; 

(4) Green berries; and, 
21

(5) Other means. 

(d) Tolerances as specified in §51.3478 (a) and (b) and applied pursuant to §51.3479. 

Size Classifications

§51.3477 Size classifications.

The following size classifications may be used in specifying size of blueberries: 

(a) Extra large. Less than 90 berries per cup1

; 

(b) Large. 90 to 129 berries per cup1

; 

(c) Medium. 130 to 189 berries per cup1

; and, 

(d) Small. 190 to 250 berries per cup1

. 

(e) For tolerances see §51.3478. 

Tolerances

§51.3478 Tolerances.

In order to allow for variations incident to proper grading and handling, based on sample inspection, the 

following tolerances, by count, shall be allowed: 

(a) For defects at shipping point2

. Ten percent for blueberries which have attached stems. Additionally, 

not more than 8 percent of the blueberries may be below the remaining requirements of the grade: 

Provided, that included in this amount not more than 4 percent shall be allowed for defects causing 

serious damage, including in this latter amount not more than 1 percent for blueberries which are affected 

by mold or decay. 

(b) For defects en route or at destination. Ten percent for blueberries which have attached stems. 

Additionally, not more than 12 percent of the blueberries may be below the remaining requirements of the 

grade: Provided, that included in this amount not more than the following percentages shall be allowed 

for defects listed: 

(1) 8 percent for blueberries which fail to meet the requirements for this grade because of permanent 

defects; or, 

(2) 6 percent for blueberries which are seriously damaged, including therein not more than 4 percent for 

blueberries which are seriously damaged by permanent defects and not more than 2 percent for 

blueberries which are affected by mold or decay. 

(c) Off-size. When size is designated according to one or more of the size classifications in 51.3477, not 

more than 10 percent of the samples in any lot or one sample, whichever is the greater number, may fail 

to meet the range in count specified. 

Application of Tolerances 

51.3479 Application of tolerances.

Individual samples are subject to the following limitations: Provided, that the averages for the entire lot 

are within the tolerances specified for the grade: 

(a) For a tolerance of 10 percent or more, individual samples may contain not more than one and one-half 

times the tolerance specified. 

(b) For a tolerance of less than 10 percent, individual samples may contain not more than double the 

tolerance specified. 

Definitions

§51.3480 Similar varietal characteristics. 

"Similar varietal characteristics" means that the berries are similar in color and shape. 

§51.3481 Clean. 

"Clean" means that the individual berry is practically free from dirt, frass, or other foreign material. 

§51.3482 Well colored.

"Well colored" means that more than one-half of the surface of the individual berry is blue, bluish-purple, 

purple, bluish-red, or bluish-black. 

§51.3483 Overripe.

 

1

Cup equals 237 ml, 1/2 pint, or 2 gills. 

2

Shipping point, as used in these standards, means the point of origin of the shipment in the producing 

area or at port of loading for ship stores or overseas shipment, or, in the case of shipments from outside 

the continental United States, the port of entry into the United States. 
22

"Overripe" means that the individual berry is dead ripe, the flesh is soft and mushy, and past commercial 

utility. 

§51.3484 Damage.

"Damage" means any specific defect described in 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 blueberries. The following specific defects shall 

be considered as damage: 

(a) Wet berries when the individual berry is wet from juice from crushed, leaking, or decayed berries, but 

not due to condensation; 

(b) Clusters when there are three or more joined capstems with at least one berry attached; 

(c) Shriveling when the wrinkling is readily noticeable; 

(d) Broken skins when not well healed or when well healed and readily noticeable, except for an 

allowable area within a 1/8 inch (3.2 mm) circle centered at the stem scar; 

(e) Scars when affecting more than 20 percent of the surface of the individual berry; and, 

(f) Green berries when one-half or more of the berry is green. 

§51.3485 Serious damage.

"Serious damage" means any specific defect described in 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 marketing quality of the blueberries. The following specific 

defects shall be considered as serious damage: 

(a) Decay; 

(b) Moldy berries; 

(c) Overripe berries; 

(d) Crushed, split, or leaking berries; 

(e) Mummified berries when the individual berry is dried up, withered or shrunken; 

(f) Insects or when there is any visible evidence of the presence of insects, including but not limited to an 

insect, the insect larva, feeding, webbing or frass; 

(g) Broken skins when not well healed; and, 

(h) Scars when affecting more than 50 percent of the surface of the individual berry. 
23

Appendix IV – Examples 

Example 1 - Inspection Notesheet 
24

Example 1 - Inspection Certificate 
25

Example 2 - Inspection Notesheet 
26

Example 2 - Inspection Certificate 
27

Example 3A - Inspection Notesheet 
28

Example 3B - Inspection Notesheet 
29

Example 3A - Inspection Scoresheet 
30

Example 3B - Inspection Scoresheet 
31

Example 3A - Inspection Certificate 
32

Example 3B - Inspection Certificate 
33

Example 4 - Inspection Notesheet 
34

Example 4 - Inspection Scoresheet 
35

Example 4 - Inspection Certificate