Made from the fermented mash of grains such as barley, corn, oats, rye and wheat. “Straight whiskey” must be made from at least 51% of one grain, must not exceed 160 proof, must be aged in oak barrels for 2 years, and must not be diluted to less than 80 proof. “Blended whiskey” is a combination of two or more 100 proof straight whiskies blended with neutral spirits, light whiskies or grain spirits.