Whiskey is an alcoholic beverage distilled from fermented grain mash and aged in wooden casks. The grains used can 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 methods, and places of origin. Scotch must be produced in Scotland from malted barley and matured in oak for at least three years.