What Difference Can A Whisky Cask Make?

By law the only ingredients allowed in scotch are malted barley, water and yeast, caramel colouring can be added for colour. Due to this a lot of whisky can taste the same so the cask and the length of time it is held in the cask is what can make each whisky distinctive from the competitors.

Maturing whisky in oak casks actually happened by accident, centuries ago whisky was transported fresh from the distillery, they used oak casks for many reasons, they’re tough, dont leak, porous and easy to use. Upon delivery the casks would be opened and consumed immediately. However a few casks were left unopened and the whisky sat, soaking up all of the flavours of the oak. Eventually someone stumbled across the unopened whisky and with it the first aged whisky, word spread around scotland and now its a legal requirement that all scotch must be aged for at least 3 years.

There are three types of oak that are used for whisky, European oak, Japanese oak and American oak. each one has their own distinctive flavours which affect the taste of the whisky held inside. 

• European oak was originally grown in the UK and was the original cask scotch was used for, but due to the weather, the oak was slow at growing and became twisted which caused leakages. Eventually British whisky companies started buying from Russia as they grow a lot faster and straight. As the years went by other countries provided the UK with oak casks at a cheaper rate. Distilleries like Stalla Dhu and Highland Park use European oak.

• Japanese oak, known as Mizunara oak has been used since the 1930s and provided unique flavours which is associated with Japanese whisky, however Mizunara oak leaks very often so due to this the whisky tends to be aged in bourbon and sherry casks and then put in mizunara oak just to give it the Japanese characteristics. Distilleries like Suntory and Nikka use Japanese oak.

• American oak has only been used since the end of world war 2. American oak is great for whisky as it grows extremely fast, straight and also has loads of vanillins which creates a vanilla flavour. The American size oak barrel is also considered to be the perfect size for maturing whisky as it gives the perfect ratio between the amount of liquid and surface area of the barrel, this is why around 90% of whisky is matured in American bourbon barrels. Distilleries like Blantons and 1792 use American oak.

It’s not just the type of wood that affects the taste, a lot of distilleries use aged casks that have been used previously. This enhances flavour as the whisky picks up the flavours of the previous alcohol that was held in before. Some whisky is aged in sherry casks. This usually gives the whisky a deeper fuller flavour and adds a bit of fruitiness to the nose and palate. You can also age whisky in bourbon casks, these casks tend to be new but heavily charred so it releases more natural sugars and flavourings.

Written By Oliver Partington - 11/02/2020