They consist of a rectangular one or two-storey building (the "stowage") and one or more kilns in which the hops were spread out to be dried by hot air rising from a wood or charcoal fire below. 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".