Single malt whisky (and sometimes a third) time. The final spirit, called "new make spirit", generally has an alcohol content of 60 to 70%. Most new-make malt whisky is diluted to about 62.5% a.b.v. before it is placed in casks to mature. The "new-make spirit", or unaged whisky, is then placed in oak casks to mature. By law, all Scotch whisky must be aged for a minimum of three years in oak casks, though many single malts are matured for much longer. The whisky continues to develop and change as it spends time in the wood, and maturation periods of twenty years or
Scotch whisky also encounter the term "single cask", signifying the bottling comes entirely from one cask. The term "blended malt" signifies that single malt whisky from different distilleries are blended in the bottle. The Cardhu distillery also began using the term "pure malt" for the same purpose, causing a controversy in the process over clarity in labelling – the Glenfiddich distillery was using the term to describe some single malt bottlings. As a result, the Scotch Whisky Association declared that a mixture of single malt whiskies must be labelled a "blended malt". The use of the former terms "vatted malt" and "pure