Barrel

A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, usually alcoholic beverages; a small barrel or cask is known as a keg. Barrels have a variety of uses, including storage of liquids such as water, oil, and alcohol. They are also employed to hold maturing beverages such as wine, cognac, armagnac, sherry, port, whiskey, beer, arrack, and sake. Other commodities once stored in wooden casks include gunpowder, meat, fish, paint, honey, nails, and tallow. Modern wooden barrels for wine-making are made of English oak (Quercus robur), white oak (Quercus petraea), American white oak (Quercus alba), more exotic is mizunara oak (Quercus crispula), and recently Oregon oak (Quercus garryana) has been used. Someone who makes traditional wooden barrels is called a cooper. Today, barrels and casks can also be made of aluminum, stainless steel, and different types of plastic, such as HDPE. Early casks were bound with wooden hoops and in the 19th century these were gradually replaced by metal hoops that were stronger, more durable and took up less space. Barrel has also been used as a standard size of measure, referring to a set capacity or weight of a given commodity. For example, in the UK and Ireland, a barrel of beer refers to a quantity of 36 imperial gallons (160 L; 43 US gal), and is distinguished from other unit measurements, such as firkins, hogsheads, and kilderkins. Wine was shipped in barrels of 119 litres (31 US gal; 26 imp gal). A barrel of oil, defined as 42 US gallons (35 imp gal; 160 L), is still used as a measure of volume for oil, although oil is no longer shipped in barrels. The barrel has also come into use as a generic term for a wooden cask of any size.