Under the grade label program, consumer packages bear an official identification indicating the U.S. grade. As a part of the acceptance service, the user has all deliveries examined by USDA to certify that they meet specifications. This assures compliance with purchase announcement specifications and helps assure that the products will maintain their quality. The stocks of Government-owned dairy products are inspected periodically to ensure that quality has not deteriorated during storage. Almost all dairy products can be graded, but the service is used most widely for butter, Cheddar cheese, instant nonfat dry milk, and regular nonfat dry milk.
Inspectors also grade other cheeses, dry whey, dry buttermilk, and dried and condensed milk.
The ratings are assigned on the basis of flavor, body, and color. The quality of the cream from which the butter is made determines the flavor factor in assigning the grades. To rate the top grade, the cheese must have a consistently fine Cheddar flavor. If instant nonfat dry milk meets the standard for quality, it may carry the U.S. Extra grade shield. This means that laboratory tests show that it possesses a sweet and pleasing flavor, a natural color, and satisfactory solubility.