Whiskey (from the Gaelic for «water of life»), spirituous liquor distilled from a fermented mash of grains, usually rye, barley, oats, wheat, or corn. Inferior whiskeys are made from potatoes, beets, and other roots.

The standard whiskeys of the world are Scotch (commonly spelled whisky ), Irish, American, and Canadian. The Scotch Highland whisky (made in pot stills) and that of the Lowlands (patent stills) differ in the percentage of barley used, quality of the water, quantity of peat employed in curing the malt, manner of distilling, and kind of casks in which they are matured. Irish whiskey resembles Scotch, but no peat is used in the curing, and instead of the dry, somewhat smoky flavor of Scotch, it has a full, sweet taste.

American whiskeys are divided into two main varieties, rye and bourbon, a corn whiskey that derives its name from Bourbon co., Ky. They have a higher flavor and a much deeper color than Scotch or Irish and require from two to three years longer to mature. Newly made whiskey is colorless, the rich brown of the matured liquor being acquired from the cask in which it is stored. Canadian whiskey has a characteristic lightness of body and must, according to law, be produced from cereal grain only.

Whiskey was made in England in the 11th cent., chiefly in monasteries, but in the 16th cent. distilling was carried on commercially. No whiskey can be released from bond in Great Britain until it has matured in wood at least three years, and in practice most whiskey is stored seven or eight years before marketing. In the United States bonded whiskey must stay a minimum of four years in bond before it can be labeled as bonded rye or bourbon.

The illicit manufacture of whiskey to avoid payment of excise taxes has been common. In the United States this is known as moonshining.