The aging process stops once the whiskey leaves the cask and is bottled. Once bottled, the flavor does not improve, opposed to wine, which does. In the cask, it's the action of the spirit interacting with the wood, as well as the evaporation over years that is the aging process. The longer in the cask, the more is lost, called the "Angel's Share". Different woods also provide different flavors. Typically, bourbon is aged in charred, new oak casks. These casks are often then shipped to Scotland and then used again for Scotch.
Other things like sherry casks and port pipes are sometimes also used for aging.
Another thing that has been happening with American Whiskey is that some producers of Small Batch whiskey have been doing is using traditional pot stills to make it, as opposed to using more modern continuous stills. This improves the flavor, and is the same method used in Scotland.
Regards
Ken
Last edited by Ken61; 03/10/17 11:39 AM.
