A building in which hops are dried and stored, usually 19th century in date and detached from the main group in order to minimise the fire risk. It comprises a kiln, with a cowl on the roof that would extract air through the drying floor on which he hops were laid, and a rectangular stowage attached where the hops could cool on an upper floor before being pressed into 'pockets' and stored on the ground floor. Early purpose built oast houses, small buildings which included a kiln and rooms for the green and dried hops, are extremely rare. Evidence for early kilns may survive in some barns. Domestic conversion has generally resulted in the loss of the hearths of the plenum chamber where the kilns were located and the press where sacks or 'pockets' were filled. Surviving examples are of great rarity.