What is "oast house"

n. (context British English) a building containing oasts, used in conjunction with hop harvesting.

n. a building containing an oast (a kiln for drying hops); usually has a conical or pyramidal roof

An oast, oast house or hop kiln is a building designed for kilning (drying) hops as part of the brewing process. They can be found in most hop-growing (and former hop-growing) areas and are often good examples of vernacular architecture. Many redundant oasts have been converted into houses.

They consist of two or three storeys on which the hops were spread out to be dried by hot air from a wood or charcoal-fired kiln at the bottom. The drying floors were thin and perforated to permit the heat to pass through and escape through a cowl in the roof which turned with the wind. The freshly picked hops from the fields were raked in to dry and then raked out to cool before being bagged up and sent to the brewery. The Kentish dialect word kell was sometimes used for kilns ("The oast has three kells.") and sometimes to mean the oast itself ("Take this lunchbox to your father, he's working in the kell."). The word oast itself also means "kiln".

The earliest surviving oast house is that at Cranbrook near Tunbridge Wells which dates to 1750 but the process is documented from soon after the introduction of hops into England in the early 16th century. Early oast houses were simply adapted barns but, by the early 19th century, the distinctive circular buildings with conical roofs had been developed in response to the increased demand for beer. Square oast houses appeared early in the 20th century as they were found to be easier to build. In the 1930s, the cowls were replaced by louvred openings as electric fans and diesel oil ovens were employed.

Hops are today dried industrially and the many oast houses on farms have now been converted into dwellings. One of the best preserved oast house complexes is at The Hop Farm Country Park at Beltring.