Ale barrels, also known as kegs, are large metal containers used to store and transport beer. They are typically filled with a variety of ales, such as lagers, stouts, and porters. Ale barrels are usually made of stainless steel and have a capacity of around 30 gallons. They are often tapped with a spigot or tap, allowing for easy pouring of the beer. Ale barrels are commonly used in pubs and bars, as well as at festivals and other events.