Wheat whiskey is a style of whiskey defined by having a grain bill which consists primarily of wheat. The United States government only allows a product to be labeled "wheat whiskey" when the mash is composed of at least 51% wheat. Like other American styles, a wheat whiskey may be labelled as a "straight" if it is aged for at least two years in new, charred oak barrels. As of 2013, only a few straight wheat whiskey are mass marketed, including Bernheim Original and Dry Fly. Some microdistilleries are in production of wheat whiskeys, but are made on a small scale.