A U.S. beer barrel is a standard unit of measurement for beer, equivalent to 31 gallons or approximately 117.3 liters. This measurement is commonly used in the brewing industry to quantify production and sales. The term "barrel" can also refer to the physical container used for aging and storing beer, typically made of wood or stainless steel. In the context of brewing, a barrel can hold about 2,000 ounces of beer, which is roughly 165 twelve-ounce servings. The U.S. beer barrel is an important metric for breweries, distributors, and retailers, helping to standardize the production and sale of beer across the industry.