Final answer:
American rye whiskey must contain at least 51 percent rye mash and usually includes corn and barley as the other two grains in the mash.
Step-by-step explanation:
American rye whiskey must, by law, contain at least 51 percent rye mash. The other two grains that usually make up the rest of the mash are corn and barley. These grains provide flavor, sweetness, and enzymes needed for fermentation and distillation.