Rye whiskey can refer to two different, but related, types of whiskey:
Rye (Secale cereale) is a grass grown extensively as a grain, a cover crop and a forage crop. It is grown principally in an area from Eastern and Northern Europe into Russia. It is much more tolerant of cold weather and poor soil than other cereals, making it useful in those regions; its vigorous growth suppresses weeds and provides abundant forage for animals early in the year. It is a member of the wheat tribe (Triticeae) which includes the cereals wheat and barley. It is likely that rye arrived in Europe as a secondary crop, meaning that it was a minor admixture in wheat as a result of Vavilovian mimicry, and was only later cultivated in its own right.
Rye grain is used for bread, beer, rye whiskey, and animal fodder. In Scandinavia, rye was a staple food in the Middle Ages, and rye crispbread remains a popular food in the region. Europe produces around half of the world's rye; relatively little is traded between countries. A wheat-rye hybrid, triticale, combines the qualities of the two parent crops and is produced in large quantities worldwide. In European folklore, the Roggenwolf ("rye wolf") is a carnivorous corn demon or Feldgeist.
American whiskey is whiskey (a distilled beverage produced from a fermented mash of cereal grain) produced in the United States. The best known American whiskey is straight whiskey, which is characterized by a mash consisting of a predominant grain (at least 51% of the mash) and, with some exceptions, aged in new charred white oak barrels. Examples of straight whiskeys include bourbon whiskey, rye whiskey, Tennessee whiskey, rye malt whiskey, malt whiskey, wheat whiskey, and corn whiskey.
Other American whiskeys include blended whiskeys, light whiskeys, and spirit whiskeys. Laws regulating the products vary between those produced for sale in the U.S. and those exported abroad.