Beer, alcoholic beverage produced by extracting raw materials with water, boiling (usually with hops), and fermenting. In some countries, beer is defined by law—as in Germany, where the standard ingredients, besides water, are malt (kiln-dried germinated barley), hops, and yeast.
Before 6000 bce, beer was made from barley in Sumer and Babylonia. Reliefs on Egyptian tombs dating from 2400 bce show that barley or partly germinated barley was crushed, mixed with water, and dried into cakes. When broken up and mixed with water, the cakes gave an extract that was fermented by microorganisms accumulated on the surfaces of fermenting vessels.