A cask that holds a quarter of a barrel, which is 10.8 US gallons or 9 Imperial gallons.

A method of fermentation by which all microorganisms necessary for fermentation are naturally occurring in the brewery and the brewer adds no cultures of microorganisms.

A large oaken barrel used for either long term fermentation or primary fermentation, particularly for wild farmhouse and sour beer styles. Pronounced FOOD-er and sometimes spelled foedre or foudre.