Single malt whiskies

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.

All single malt goes through a similar batch production process, as outlined below. There are several types of single malts available from distilleries including single barrel single malts which are the product of a single batch that was stored for three or more years in a single oak barrel. These single barrel variants afford the opportunity for the consumer to see the influence of different types of storage on the same whisky (e.g., first use bourbon whiskey barrels, port pipes, etc.). The more common form of Single Malt is a marrying at bottling time of various batches that are mixed or vatted to achieve consistent flavours from one bottling run to the next.

Water is first added to the barley to promote germination. At a later stage, prior to fermentation, it is mixed with ground barley grist to create a mash. Water is also used later in the production process to dilute most whisky before maturation, and added once again before bottling.

Most new-make malt whisky is diluted to about 60% alcohol by volume (ABV) or so before it is placed in casks to mature (62.5% is specified as a maximum in U.S. law for making straight whisky). The aged spirit is then diluted with water to reduce it to bottling strength (typically 40-50% ABV). Since large amounts of water are used during the process of whisky production, water supplies are a key factor for the location of any distillery.

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Wikipedia