(a) Ice cream shall contain at least 1.6 pounds of total solids to the gallon, weigh not less than 4.5 pounds to the gallon, and contain not less than 20 percent total milk solids, constitued of not less than 10 percent milkfat. In no case shall the content of milk solids not fat be less than 6 percent. Whey shall not, by weight, be more than 25 percent of the milk solids not fat.

(b) When one or more of the bulky optional ingredients, as approved by the Food and Drug Administration, are used, the weights of milk fat and total milk solids (excusive of such fat and solids in any malted milk used) are not less than 10 percent and 20 percent, respectively, of the remainder obtained by subtracting the weight of such optional ingredients, from the weight of the finished ice cream; but in no case is the weight of milk fat or total milk solids less than 8 percent and 16 percent, respectively, of the weight of the finished ice cream. In calculating the reduction of milk fat and total milk solids from the use of bulky optional ingredients, chocolate and cocoa solids used shall be considered the bulky ingredients. In order to make allowance for additional sweetening ingredients needed when bulky ingredients are used, the weight of chocolate or cocoa solids may be multiplied by 2.5; the weight of fruit or nuts used may be multiplied by 1.4; and the weight of partially or wholly dried fruits or fruit juices may be multiplied by appropriate factors to obtain the original weights before drying and this weight multiplied by 1.4 The finished ice cream contains not less than 1.6 pounds to the gallon; except that when the optional ingredient microcrystalline cellulose is used, the finished ice cream contains not less than 1.6 pounds of total solids to the gallon and weighs not less than 4.5 pounds to the gallon exclusive, in both cases, of the weight of the microcrystalline cellulose.

(c) Optional characterizing ingredients, optional sweetening ingredients, stabilizers, and emulsifiers as approved by the Food and Drug Administration may be used.