Green tea is produced by steaming the leaves to destroy the enzymes that might otherwise ferment the leaves. The leaves are then rolled either by hand or by mechanical rollers, to bring out the juices in the leaves that are responsible for its flavor. The rolled leaves are then fired to dry them. The entire process of rolling and firing is repeated several times until the leaves are completely dry. The process of producing green tea is very exacting because variation in the drying time can result in fermentation of the leaves which spoils its flavor.