Whisky maturation: Cask influence over time

1. Unwanted characteristics– such as harshness and immaturity – are reduced over time.

2. Delicate distillery character– that is, flavour congeners developed during the process such as fruity and grassy – stay in the spirit.

3. Cask impact– that is, flavour and colour compounds from the wood – influence the spirit over time.

The sweet spot of when a whisky is deemed ready will be different for each distillery, each spirit and even each cask. But there is a time when a) the unwanted characteristics are gone, b) the distillery character is shining through and c) the wood has impacted the spirit just enough.

Maturation is such an important stage of the whisky making process and, if mistakes are made, it can have a serious impact on the final product. If the maturation period is too short, for example, the whisky may be too harsh whereas if it is left in the cask for too long , the whisky could be too woody.