AI Summary
Bourbon whiskey, known for its rich flavor and deep amber hue, must adhere to specific rules to be classified as bourbon. These rules include being made in the U.S. or a U.S. territory, specific grain mixtures, aging processes, and alcohol proof. The mash bill, or recipe of grains, is a key factor in bourbon's distinct flavors. The mash bill must contain at least 51% corn, with malted barley, rye, and wheat often used for additional flavoring.
Few beverages have as rich a heritage and as complicated a chemistry as bourbon whiskey, often called “America’s spirit.” Known for its deep amber hue and robust flavors, bourbon has captured the hearts of enthusiasts across the country.
But for a whiskey to be called a bourbon, it has to adhere to very specific rules. For one, it needs to be made in the U.S. or a U.S. territory—although almost all is made in Kentucky. The other rules have more to do with the steps to make it—how much corn is in the grain mixture, the aging process and the alcohol proof.
I’m a bourbon researcher and chemistry professor who teaches classes on fermentation, and I’m a bourbon connoisseur myself. The complex science behind this aromatic beverage reveals why there are so many distinct bourbons, despite the strict rules around its manufacture.
The mash bill
All whiskeys have what’s called a mash bill. The mash bill refers to the recipe of grains that makes up the spirit’s flavor foundation. To be classified as bourbon, a spirit’s mash bill must have at least 51% corn—the corn gives it that characteristic sweetness.
Almost all bourbons also have malted barley, which lends a nutty, smoky flavor and provides enzymes that turn starches into sugars later in the production process.
Many distillers also use rye and wheat to flavor their bourbons. Rye