WHAT IS CASK WHISKY AND WHY IS IT IMPORTANT?
The Scotch Whisky Association (SWA), the governing body protecting Scotch, defines a cask as ‘an oak barrel not exceeding 700 litres’. The largest typical cask in use is the butt, which in most cases will have been used in the production of sherry. Those familiar, dark-coloured and richly flavoured whiskies are likely to have been matured in one of these casks.
Therefore, the main defining factor in the entire style of a whisky is the cask in which it matures. Many experts agree that as much as 80% of a whisky’s characteristic flavour comes from the wood. With Scotch whisky, a single cask is often used several times before the wood has lost most of its flavour. In fact, fresh casks are often unsuitable for a long maturation as too much flavour can be imparted. Used casks sometimes go through a rejuvenation process. In such process the active wood is separated from the inactive and toasted, ready to be used again.
First-fill casks extract the strongest flavours from the wood. When speaking of a “first fill”, this refers to the first time it’s used to age Scotch whisky after being emptied of its previous liquid. Such as Sherry, Port or Bourbon.
Before bottling, most whiskies are brought down to a standard percentage of alcohol (most commonly 40 or 43%). This is done by adding water to the spirit. This helps to maintain consistency, increases the amount of whisky and the lower strength appeals to a wider market. Very occasionally, whisky is bottled at the ABV at which it is drawn from the cask: this is ‘cask strength’ whisky. The strength varies from cask to cask, being affected by the ‘angel’s share’. Each single cask has its own individual character and unique relationship with the wood it has matured in. And therefore makes cask-strength single-cask whisky highly desirable to enthusiasts and collectors. The ABV can be in the high 60s for younger malts, whereas older whiskies may soften down to the low 40s.
Many people recommend a little water to dilute their whisky to suit their personal taste. By carefully adding a couple of drops, you will notice subtle changes to the texture and flavour. The flavour molecules (especially fatty acids) are often physically bound to the alcohol. Water helps to break down this bond and release a more intense flavour. However, with a few whiskies the flavour is strongly supported by the alcohol, and the addition of water can make the flavour structure collapse. There is no right or wrong – we recommend you experiment and find your own personal preference!