Brewery cask is a type of container used for storing and transporting beer. It is also known as a KEG, which is a three-letter word that is often used to describe it. The brewery cask is made of stainless steel and is designed to hold large amounts of beer. It is usually filled with carbon dioxide or nitrogen to keep the beer fresh and prevent it from going flat. Brewery casks are often used in pubs and bars to serve draught beer.