Which of the following is NOT a characteristic of American whiskey?

American whiskey, particularly types such as bourbon, is primarily characterized by its grain content, where corn makes up at least 51% of the mash bill. This grain predominantly influences the sweet flavor profile commonly associated with American whiskey.

The aging process is also significant; American whiskey is typically aged in new, charred oak barrels. This charring process contributes to the distinctive flavors and colors of the final product, enhancing complexity and richness.

While malted barley can be a component of some American whiskeys, particularly in certain recipes for products like bourbon or rye, it is not a defining characteristic for all American whiskeys. Bourbon, for instance, is primarily composed of corn, and the legal definition requires a specific mash bill that prioritizes corn over malted barley. Additionally, American whiskey often undergoes distillation processes, but the distinction between being distilled more than twice is not as definitive as the characteristics involving its grain composition and aging.

Thus, the characteristic that is not typically associated with American whiskey, in a defining sense, is the requirement of containing malted barley, making it the correct choice in this question.