Single malt whiskey must be made from a single distillery and from a single grain: barley. The Scotch single malts are well known, highly regulated and respected, but the American version is becoming quite the trend. American malt whiskey must be made from 51% malted barley. Distillers can also use peat (like many Scotches do) or other smoking techniques in the process, resulting in a charred or smoky flavor. Check out the best American malt whiskies in this growing, new category.