Jeremy Kasler

Bourbon dictionary

Common terms in bourbon

Ever since I developed an interest in bourbon with that first sip, I’ve amassed quite a vocabulary of terms specific to bourbon and whiskey production. So I decided just to list everything I’ve soaked up these last few years to share it with others and serve as a database for myself. 

I’m sure I’ll be adding to this list, so check back often. You never know when you’re going to be quizzed on all things bourbon.


Age: The process of letting whiskey mature in oak barrels.

Alcohol By Volume (ABV): Percentage of alcohol in the spirit.

Angel’s Share: Product that evaporates from a barrel over time.

Barrel Strength: Whiskey that has been bottled at the proof it came out of the barrel, with no water added.

Bourbon: A type of whiskey that is made in America, contains at least 51% corn in the mash bill, aged in new, charred-oak barrels, cannot contain any additives, etc.

Bottled In Bond: Guidelines set forth by the 1897 Act that states a BIB bourbon must be made in one distillery, in one season, aged for at least four years, and be bottled at 100 proof.

Bung: The wooden stopper in the bung hole that seals the barrel.

Char: The burnt wood inside a bourbon/whiskey barrel.

Cooperage: The place where barrels are made.

Devil’s Cut: The liquid that has been absorbed into the barrel after dumping.

Entry Proof: The proof at which the spirit is put into a barrel.

Finished: A bourbon that is transferred to a second type of barrel after it is aged, usually barrels that previously held wine, sherry, port or rum.

Malted: When a grain starts the sprouting process.

Mash: The liquid and grain mix created during the cooking process. 

Mash Bill: The grain recipe of a distillate. 

Master Distiller: The person who determines the recipe for the whiskey and oversees production.

Proof: The amount of alcohol in a spirit. (Proof is double the ABV.)

Rick House: The warehouse where barrels age.

Rye Whiskey: Whiskey made from at least 51% rye grain in the mash bill.

Scotch: A type of whiskey made in Scotland, mostly using malted grains in the mash bill, and aged at least three years in oak barrels or casks.

Single Barrel: Bottling from just one barrel.

Small Batch: Bottling from a small selection of barrels.

Sour Mash: Process of using a portion of the liquid stillage left after a distillation run in the cook of the next batch.

Stave: The planks of oak that create a barrel.

Still: An apparatus used to distill spirits.

Sweet Mash: Using only fresh water for the cooking process — no leftover stillage is set back from a previous batch.

Unfiltered: Spirit that has not been chill filtered, a process that removes fatty acids from the distillate.

Whiskey: A spirit made from fermented grains.

Whiskey Thief: An instrument created to remove a sample of whiskey out of the barrel’s bung.

White Dog/New Make: The colorless, unaged distillate that goes into the barrel.