Warehouse – The distillate matures to become Malt Whisky
The young distillate (new-make spirit) is filled into oak casks. Most Malt Whiskies are matured in casks of American white oak which had a first fill of bourbon whiskey. To a lesser degree, casks of Spanish or French oak formerly filled with sherry are used.
There is a law that the distillate has to mature at least three years in such wooden casks before it is allowed to be called Scotch Whisky. During maturation, some substances of the wood as well as the colour and the aroma of the beverage the cask was originally filled with dissolve into the maturing whisky thus granting it an ideal development of aroma and flavour.
Lots of Malt Whiskies mature for more than ten years. Every year, a cask loses about 2 % of its content due to evaporation:
“The Angels Share”