Designation for a barrel-shaped (cylindrical) mostly bulbous container of various materials such as wood, metal, plastic or ceramic for the storage of liquids. In viticulture, barrels are mostly made of wood, because this material is breathable and a metered access of oxygen allows what is usually desired when expanding wine. For filling and emptying, it has a small, as bung (Bunghole) designated opening. It can also be open on one side and is then provided with a lid. For large barrels, an entry point in the ground ( barrel bolt ) for one person cleaning. The roller shape allows effortless handling, moving and space-saving stacking.
Barrels of various types and volumes play in relation to the expansion a significant role.