Dry mixtures containing less than 31 percent by weight of butterfat and consisting of not less than 17.5 percent by weight each of sodium caseinate, butterfat, whey solids containing over 5.5 percent by weight of butterfat, and dried whole milk, but not containing dried milk, dried whey or dried buttermilk any of which contain 5.5 percent or less by weight of butterfat