American whiskey labeled as one of these types, the whiskey must be distilled to no more than 80% alcohol by volume (160 U.S. proof) to ensure the flavor of the original mash is adequately retained, and the addition of coloring, caramel, or other flavoring additives is prohibited. All of these, except corn whiskey, must be aged at least briefly (although no minimum aging period is specified) in charred new oak containers. These restrictions do not exist for some similarly named products in some other countries, such as Canada. American corn whiskey does not have to be aged at all – but, if
Corn whiskey be barreled at lower than 125 proof (62.5% abv). In contrast, a whiskey distilled from a mash consisting of at least 80% corn in a charred new oak barrel would be considered bourbon. Aging is usually brief – six months or less – during which time the whiskey absorbs color and flavor from the barrel while the off-flavors and fusel alcohols are reduced. A variant called straight corn whiskey is also produced, in which the whiskey is stored in used or uncharred new oak containers for two years or more. Whiskeys produced in this manner and aged for at least