By federal law, bourbon must contain at least 51% corn in its mash, but not exceed 79% corn. If its contents exceed 79% corn, it must be labeled as corn whiskey. Bourbon is considered a straight whiskey. It must be distilled at 160 proof (eighty percent) or less. It must be aged a minimum of two years in NEW charred oak barrels. (Most bourbons are aged four years or longer.) Most American whiskies are distilled in continuous stills.
Since bourbon is a straight whiskey, it cannot be blended with anything except water, to lower the proof. Most bourbons are sold at eighty proof.
In recent years, ultra premium bourbons have become popular. The following are categories of ultra premium bourbons:
- Small Batch Bourbons: These are bourbons made in small quantities from a small number of barrels. These are selected from a larger batch by a master distiller.
- Single Barrel Bourbons: These bourbons are aged in a new charred barrel until maturity. Once the master distiller determines the barrel has reached its optimal maturity, the barrel is emptied, filtered, purified water is added to reduce the proof, then the product is bottled.
- Barrel Proof Bourbon: These bourbons are bottled at barrel strength with no additional water. Each batch varies slightly in proof.
By law, bourbon can be distilled anywhere in the United States. To be considered “Kentucky Bourbon,” it must be distilled and warehoused at least one year in Kentucky.
Sour mash is made by taking at least 25% of the spent mash from a previous batch of whiskey and allowing the new batch to ferment for 72 to 96 hours. This allows consistency from batch to batch.
Tennessee whiskey differs from bourbon in some phases of production. After distillation, Tennessee whiskey is poured into a vat and filtered through layers of maple charcoal, usually prior to aging. Also, it must be produced in Tennessee.
Blended whiskey is made from a combination of bourbon and grain spirits. Each brand attempts to construct just the right combination of whiskies. Every blend on our shelves contains a number of straight whiskies in their formulas. A blend must contain at least 20% straight whiskey.
Rye whiskey refers to whiskey made from a mash comprised of at least 51% rye.
Wheat whiskey refers to whiskey made from a mash comprised of at least 51% wheat.
Bottled in Bond
This refers to straight whiskey that is aged in “bonded” United States government warehouses for at least four years and bottled at 100 proof.