7 C.F.R. § 51.885
“U.S. No. 1 Institutional” grapes must have no less than 95 percent of the containers in the lot legibly marked “Institutional Pack.” Further requirements for this grade include grapes which consist of clusters and/or bunches of well developed grapes of one variety, except when designated as assorted varieties, which are at least fairly well colored, uniform in appearance when so specified in connection with the grade, and which meet the following requirements:
(a) Basic requirements for berries:
(c) Berries free from:
(d) Stems free from:
(f) Bunches not damaged by:
(g) Stems not damaged by:
(h) Size:
(2) For clusters/bunches: In this grade grapes shall consist of at least a two berry cluster ranging to clusters and/or bunches of grapes not greater than five ounces in weight. See section 51.913.
[61 FR 11126, Mar. 19, 1996, as amended at 64 FR 14576, Mar. 26, 1999]