dry milk means: Dry milk is a product that has almost all of the water removed from the milk, leaving only the solids. There are three types of dry milk: buttermilk, whole milk, and nonfat milk. Although dry milk can be stored more easily than fresh milk, it is cheaper and less costly to purchase. However, dried whole milk should still be kept refrigerated due to its high milk fat content and its taste that is not quite as good. (in Cooking Dictionary)