A drying chamber, also known as an OAST, is a building used in the process of drying hops. It is typically cylindrical in shape and has a conical roof. The OAST is heated by a kiln, which is usually located at the base of the building. The heat from the kiln is then circulated through the drying chamber, allowing the hops to dry evenly. The dried hops are then stored in a separate chamber until they are ready for use.