Single malt whisky

Single malt whisky is malt whisky from a single distillery, that is, whisky distilled from fermented mash made exclusively with malted grain (usually barley), as distinguished from unmalted grain.

Single malts are typically associated with single malt Scotch, though they are also produced in various other countries. Under Scotch Whisky Regulations, a "Single Malt Scotch Whisky" must be made exclusively from malted barley (although the addition of E150A caramel colouring is allowed), must be distilled using pot stills at a single distillery, and must be aged for at least three years in oak casks of a capacity not exceeding 700 litres (150 imperial gallons; 180 US gallons). While the Scotch model is usually copied internationally, these constraints may not apply to whisky marketed as single malt that is produced elsewhere. For example, there is no definition of the term single with relation to whisky in the law of the United States, and some American whiskey advertised as single malt whisky is produced from malted rye rather than malted barley.

To be called a single malt whisky in Scotland, a bottle may only contain whisky distilled from malted barley and produced at a single distillery. The regulations of other countries may allow malted rye.

If the bottle is the product of malt whiskies produced at more than one distillery, the whisky is called a blended malt or vatted malt, or pure malt. If a single malt is mixed with grain whisky, the result is a blended whisky. Single malts can be bottled by the distillery that produced them or by an independent bottler.

The age statement on a bottle of single malt whisky is the age of the youngest malt in the mix, as commonly the whiskies of several years are mixed in a vat to create a more consistent house style. On occasion, the product of a single cask of whisky is bottled without being vatted with other casks, and released as a "Single Cask" offering. However, it is not always clear what the term "single cask" refers to. At least some producers release vattings of multiple barrels that have been matured together for one final period in a larger single cask as "single cask" whisky.

While cask-strength, or undiluted, whisky (sometimes having an alcohol content upwards of 60%) has recently become popular, the vast majority of whisky is diluted to its "bottling strength" - between 40% and 46% ABV - and bottled for sale.