Scotch whisky whisky" is any spirit that qualifies as a single malt Scotch whisky or as a blended Scotch whisky. The latter exclusion is to ensure that a blended Scotch whisky produced from single malt(s) and single grain(s) distilled at the same distillery does not also qualify as single grain Scotch whisky. Three types of blends are defined for Scotch whisky: The five Scotch whisky definitions are structured in such a way that the categories are mutually exclusive. The 2009 regulations changed the formal definition of blended Scotch whisky to achieve this result, but in a way that reflected traditional and current
Cask strength on storage conditions. Scotch whisky is typically aged in used barrels, and due to the relatively cool climate in Scotland, the proof level typically stays the same or goes down during maturation. In contrast, American bourbon whisky is produced using new barrels, and storage conditions in Kentucky and Tennessee where nearly all of it is produced allow the proof levels to rise during aging. The vast majority of whisky bottled has been watered down to about 40–46% ABV, although some whiskies marketed for whisky enthusiasts are bottled at proof levels all the way up to cask strength. In the United