N.Y. Comp. Codes R. & Regs. tit. 1, § 162.21 – Mushroom standards.

(1) Similar varietal characteristics means that the mushrooms are of the same general color. For example, white and brown mushrooms shall not be mixed in the same container.
(2) Mature means that the mushroom is firm and well developed; the veil area may be stretched but not broken.
(3) Well shaped means that the mushroom cap is not flattened, scalloped, indented or otherwise deformed to an extent which slightly detracts from the appearance or marketing quality.
(4) Fairly well shaped means that the mushroom cap is not flattened, scalloped, indented or otherwise deformed to an extent which materially detracts from the appearance or marketing quality.
(5) Well trimmed means that the stems are smoothly cut, free from rough fleshy butts, the flared portion of the butt is removed and the remaining portion of the stem does not exceed the depth of the cap.
(6) Open veils means that the cap has expanded to the extent that the protective covering or veils joining the margin of the cap to the stem have broken and exposed the gills or underside of the cap.
(7) Spots means pitted or discolored areas.
(8) 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 individual mushroom or of the mushrooms in the lot. The following specific defects shall be considered as damage:
1. (i) Discoloration when the color of the cap or stem materially affects the appearance or marketing quality of the mushrooms.
2. (ii) Dirt when any amount is embedded in the cap or stem.
(9) Length of stem means the greatest distance as measured from the point of attachment of the veils on the stem to the butt.
(10) Diameter means the greatest dimension of the cap measured at right angles to the stem.
(c) Size.
Size is specified in terms of diameter and unless otherwise specified meets the requirements of one of the following size classifications:
(1) Small to medium—up to 1 5/8 inches in diameter.
(2) Large—over 1 5/8 inches in diameter.
(d) Tolerance.
In order to allow for variations incident to proper grading and handling the following tolerances, by weight, are provided as specified:
(1) For defects. Five percent for mushrooms in any lot which fail to meet the requirements of these specifications, but not more than one-fifth of this amount or one percent shall be allowed for mushrooms affected by disease, spots or decay.
(2) For off-size. Ten percent for mushrooms in any lot which fail to meet the specified size requirements.
(e) Application of tolerances.
The contents of individual packages in the lot, based on sample inspection are subject to the following limitations:
(1) For a tolerance of 10 percent or more, individual packages in any lot shall have not more than one and one-half times the tolerance specified: provided, that the average for the entire lot is within the tolerance specified.
(2) For a tolerance of less than 10 percent, individual packages in any lot shall have not more than double the tolerance specified, except that at least one defective and one off-size specimen may be permitted in any package: provided, that the average for the entire lot is within the tolerance specified.
(f) Packing.
Mushrooms must be packed in new standard containers subject to approval by the Department of Agriculture and Markets. Container approval shall be based upon the ability of the container to maintain the quality standards and integrity of the product.
(g) Markings.
Each container or display of mushrooms offered for sale under the Seal of Quality program shall have the official seal designation.

(a) General.

New York State Seal of Quality mushrooms shall be fresh mushrooms of similar varietal characteristics which are mature, fairly well shaped, provided 50 percent of the lot is well shaped, well trimmed, free from open veils, disease, spots, insect injury and decay, and from damage by any cause.

(b) Definitions.