(also known as barrel proof
) is a term used in whisky
-making to describe the strength of whisky in the cask during maturation. Whisky at cask strength isn't as drinkable as diluted whisky. Most bottled whisky is diluted with water to bring its strength (abv
) down to a level that makes it less expensive to produce and more palatable, usually about 40% abv – which is the statutory minimum in some countries. The degree of dilution is said to bring out different flavours of the whisky, which can affect the decisions of the producers regarding the concentration they select for the bottling of their various brands.
Cask strength bottling
While the majority of whisky bottled by distillers is watered down to about 40% abv, some whiskies are bottled at cask strength.
These whiskies are usually produced for the upper premium market category, as cask strength whisky is more expensive to produce and less palatable to casual consumers than diluted whisky. Such whiskies are usually older as well, as the whisky develops flavors coming from the long marriage of cask and liquor, to the extent that substantial aging is demanded by the more sophisticated premium-market consumers.
Sometimes bottlers dilute even cask strength bottling, but to a lesser degree, such as to 60%. This avoids the need to reprint the labels – which must state the exact alcohol level – if different barrels contain whisky at different strengths.