Butter

Butter, dairy product made by churning milk or cream, containing fat, protein, and water. Made in some countries from the milk of goats, sheep, or yaks, it is most often made from cow's milk. Continuous mechanized production has been general since the 1940s. After skimming, the cream is ripened with a bacterial culture, pasteurized, cooled to 40°F (4°C), and then churned, causing the butterfat to separate from the liquid residue, buttermilk. The butter is then washed, worked, colored, and salted.