milk

Milk is a nutrient-dense liquid secreted by the mammary glands of lactating mammals to nourish their offspring. In culinary contexts, cow's milk is the most widely used type globally, though goat, sheep, buffalo, and camel milk are significant in various regions. Milk consists primarily of water (approximately 87%), lactose (milk sugar), casein and whey proteins, and milk fat, with the precise composition varying by species, breed, diet, and lactation stage.

Whole milk typically contains 3.5-4% fat; lower-fat versions include reduced-fat (2%), low-fat (1%), and skim milk (0-0.5% fat). Raw milk differs from pasteurized milk in microbial content and enzyme activity; ultra-high temperature (UHT) processing allows longer shelf stability. Milk flavor ranges from neutral to slightly sweet and creamy, with variations influenced by animal diet, breed, and freshness.

Milk functions as both a foundational ingredient and a finished beverage across virtually all culinary traditions. It serves as a primary component in dairy products including cheese, yogurt, butter, and cream; appears in baked goods, sauces, custards, and desserts; and is essential to beverages from hot chocolate to latte preparations. In cooking, milk provides moisture, richness, and structure to béchamel and other classic sauce foundations, contributes to emulsification in soups and gravies, and facilitates the development of tender crumb in cakes and pastries.

Different milk fat contents suit specific applications: whole milk is preferred for drinking and cream-based applications, while skim or low-fat milk works well in lighter sauces and beverages. Milk can be reduced, scalded, or fermented to concentrate flavors and alter texture. Its interactions with heat, acid, and salt are fundamental to cheese-making, sauce preparation, and bread-making.