Counting Grains

• Distillers make bourbon and other whiskeys from grains, but the primary grain in the mash that's used for different types of whiskeys varies. A true bourbon comes from mash made with at least 51 percent corn, while a rye whiskey requires a mash made up of at least 51 percent rye. Other whiskey varieties have barley or wheat as the main component in the mash. The primary grain affects the color and flavor of the finished whiskey.

It Gets Better With Age

• Whiskey must undergo a strict distilling and aging regimen under U.S. regulations to carry the name “bourbon." According to the Alcohol and Tobacco Tax and Trade Bureau of the U.S. Treasury, it requires distillation to a maximum of 160 proof, followed by bottling at 80 proof. It can be no more than 125 proof when it's aged in the barrel. The barrels must also meet regulations. Barrels used for bourbon must be new and made from charred oak. A straight bourbon requires two years of aging and can't contain added flavorings or colors. Other whiskey varieties, such as rye whiskey, have similar distilling and aging requirements, although the age and material used for the barrels varies.

Taste the Difference

• For the consumer, the flavor is the most notable difference between bourbon and other whiskey varieties. Bourbon has a robust sweet flavor with a mellow spicy bite, much different from the drier, spicier flavors of rye or Scotch whisky. The combination of the high sugars in the corn mash and the aging process gives bourbon its signature spicy-sweet flavor. Bourbon also has a distinct woodiness thanks to the charred oak barrels, which gives drinks an earthy flavor that complements sweetness.

Mix It Up

• Although you can use bourbon and other whiskey varieties interchangeably in most drink recipes, bourbon's sweetness makes it a poor substitute in recipes intended for a drier-tasting alcohol. Mixed drinks that don't include other sweet alcohols make a good choice for bourbon, to keep sweetness from overpowering the flavor. For example, the tart mixer in a whiskey sour provides a counterpoint to the mild sweet spice of bourbon.