Drying: heat and draught

A hop kiln or oast house is a building in two parts: the kiln and the stowage (Fig 3.1). Inside the kiln heated air is drawn up by the A draught through a bed of hops laid on the drying floor. Below the drying floor an open hearth, stove or furnace stands on the ground in the lower part of the kiln, called the plenum chamber (because the aim was to fill it evenly with hot air). Above the drying floor the fumes and moisture from the hops were drawn up and out of the cowl or other vent at