What percentage of grains must be rye for a whiskey to be classified as Rye whiskey?

For a whiskey to be classified as Rye whiskey, it must contain at least 51% rye grain in its mash bill. This requirement is defined by regulations in the United States and ensures that the predominant flavor profile of the spirit comes from rye, which imparts a distinctive spiciness and robustness. By setting the threshold at 51%, the classification highlights the primary ingredient that characterizes Rye whiskey and differentiates it from other types of whiskey, such as Bourbon, which must contain at least 51% corn. Thus, this percentage is crucial for the recognition and classification of Rye whiskey in the spirits market.