Malt whisky whisky regulations require malt whisky to be made in pot stills using water and malted barley without the addition of any other cereals, and the whisky must be aged for at least three years in oak casks. The use of new barrels is not required. Caramel coloring can be added, but no other additives are allowed. Irish whiskey regulations are almost identical to Scotch regulations. Malt whiskey must be distilled in a pot still from a mash of 100% malted barley, which may be peated or unpeated in character, although unpeated malt is typically used. All Irish whiskeys must be
Single malt Scotch whisky that contained a mixture of both barley and non-barley grain whisky, but this is no longer the case. Under the terminology established by the SWR 2009, the term "blended malt Scotch whisky" replaced the term "vatted malt" to describe a mixture of single malt Scotch whiskies (malted barley whisky). A mixture of malted barley whisky and non-barley whisky is labeled "blended Scotch whisky" (without the word "malt"). The age statement on a bottle of single malt Scotch is the number of years the whisky spent maturing in casks. Very few whiskies are bottled from a single cask, and the