Whisky is distilled from a fermented mash of grain, usually corn, rye, barley or wheat and then aged in oak barrels. When placed in these barrels to age, it is a water-colored liquid. It is during the aging period that whisky obtains its characteristic amber color, flavor and aroma.

The major whisky-producing countries are Scotland, Ireland, Canada and the United States. Special grain characteristics, recipes and distillation processes make the whisky of each country distinct from that of the others.