Whiskey is an alcoholic beverage distilled from fermented grain mash that is aged in wooden casks. The grains used include barley, corn, rye, and wheat. The whiskey making process involves malting, mashing, fermentation, distillation, and maturation. There are several types of whiskey defined by their country of origin, including Scotch whiskey from Scotland, Irish whiskey from Ireland, American whiskey such as bourbon from the United States, Canadian whiskey, and Indian whiskey. Whiskey is served in different ways depending on whether it is served straight, on the rocks, or mixed with other ingredients.