Kilning is the process of drying malted grain in a kiln using an indirect heat source to halt germination and evaporate much of the moisture from the malted grains. Kilning grain started to become popular in the early 18th century and was the predominant method for drying malt by the 19th century. Prior to kilning, malt was often dried over open flame which would impart a smoke flavor in the finished beer, similar to what you may find today in a German rauchbier.