Beer is a fermented beverage made from grain, yeast, water, and hops.
Beer is an alcoholic beveragebeverage produced by fermenting cereal grains. Typically, the grain used is primarily barley, sometimes with additional ingredients such as wheat or corn. Through the application of water and heat, enzymes convert starches in the grain to fermentable sugars. Those sugars are consumed by yeast, yielding alcohol and carbon dioxide. Since at least the 10th century, hops have been added to beer because they help reduce the risk of unwanted bacteria during fermentation and provide additional flavor.