Beer is made by fermenting water, malt, sugar, hops, yeast (species Saccaromyces spp., used for the fermentation process), salt, and citric acid. Each ingredient has a specific role in the creation of beer. For example, malt is produced from a grain—usually barley—that has sprouted, been dried in a kiln, and ground into a powder, which gives beer its characteristic body and flavor. Hops is made from the fruit that grows on the herb Humulus lupulus (a member of the mulberry family). The fruit is picked when ripe and is then dried; this ingredient gives beer its slightly bitter flavor.