Whiskey is a distilled alcoholic beverage made from fermented grain mash that is aged in wooden casks. The grains used include barley, corn, rye, and wheat. The production process involves malting, mashing, fermentation, distillation, and maturation. There are several types of whiskey including Scotch, Irish, American, Canadian, and Indian whiskey, which differ based on ingredients, production process, and place of origin. Whiskey is commonly served neat, on the rocks, or with mixers.