Now I am not saying that these factors do not influence the flavour of the spirit, although I do remain unconvinced by the unique sea salt air claim! Certainly, the type of malted barley and yeast to be used, the shape of the stills and the type of condensers were all major points for discussion in previous projects in which I have had personal involvement.
We can debate the influence of all these factors long into the night, and over several drams, but the one factor that dominates the flavour of the Scotch Whisky is the quality and type of cask used for maturation. Indeed, most within the industry would agree that about 70% of the final flavour ultimately comes down to the cask.
So, what are the various types of cask used in maturation?
The one thing that is set by the Scotch Whisky regulations is that the cask must be made of oak so let’s consider some of the terminology;
A cask can be called first fill if this is the first time it has been used to mature Scotch Whisky. A refill cask would have had Scotch Whisky in it previously.
American standard barrels are a type of cask made from American oak used to mature bourbon. As bourbon rules dictate that these casks can only be used once in bourbon maturation they are a popular choice for Scotch Whisky distillers. They hold 200 bulk litres.
Hogsheads, barriques, butts, puncheons, quarter casks, octaves are all different sizes of casks. Hogsheads generally hold 250 bulk litres while butts may hold 500 bulk litres. In whisky maturation they are often used after holding sherry, port or red wine to impart greater colour and sweetness to the Scotch Whisky. One point to note that the smaller the cask the greater the influence on the whisky from the wood as the wood to spirit ratio is greater.
You will often see on a label “finished in” sherry, port, red wine etc. This means that the spirit was likely matured for a significant period in bourbon barrels before being re-casked into a new cask for a perhaps 6-18 months to add additional complexity to the Scotch Whisky.
The choices for distillers, independent bottlers and whisky enthusiasts is extremely wide and varied resulting in a huge choice of single cask expressions from the same distilled spirit.
A common misconception is that first fill casks are better than refill casks or that sherry is better than bourbon. First fill casks might be more expensive and the whisky may react more quickly with the seasoned wood but if you want to create a Single Malt of significant age the influence of first fill sherry over a longer period might be overpowering.
All these factors add to the fun. Every cask is unique allowing you the ability to create a personal whisky with its own distinct DNA.
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