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The whiskey world has barrelfuls of lingo—there’s a lot to learn. Have you ever wondered, what is barrel proof bourbon, and is barrel proof different from cask-strength whiskey? Let’s start with that word, ‘proof’. What exactly does it mean? Where did it come from? And what does it mean for you, the bourbon drinker?
WHAT DOES PROOF MEAN IN WHISKEY?
Proof is the measure of ethanol (alcohol) in an alcoholic drink and predates the more modern measure of ABV (alcohol by volume).
Today the definition of proof in the USA is that it is equal to twice the ABV, so a bourbon of 81 proof is 31.5% ABV, while a 55.5% ABV bourbon is known as “101 proof”. While no longer required from a legal perspective, proof is often still included on spirit bottles for historical or traditional interest—and we like tradition at Wild Turkey.
WHAT IS BARREL PROOF BOURBON?
Of all the bourbon expressions, a “barrel proof” designation is often regarded as one of the most coveted. Connoisseurs and whiskey hunters are on constant alert for rare and newly released barrel proof bourbons. What makes this expression so sought-after is its purity. It’s the only bourbon expression that doesn’t have any water added before bottling. What comes out of the barrel, whatever the proof, goes straight into the bottle.
Proof can go up or down by precise increments during maturation. This means that a barrel proof bourbon’s ABV will often have a decimal point in the number. If you ever spot a strange-looking ABV on a bottle, take a closer look. Wild Turkey Rare Breed Bourbon and Rye are both barrel-proof whiskeys.
Barrel proof is the purest expression of bourbon. The higher alcohol content enhances the sensory experience with concentrated aromas and flavors that results in a deeper, more complex tasting experience.
WHAT ARE CASK STRENGHT AND FULL PROOF?
Wondering whether a cask is a barrel, or a barrel is a cask? Well, we’re happy to report that they are indeed one and the same. “Cask strength” is exactly the same thing as barrel proof, which you might also see written as barrel strength. The naming difference is purely an issue of origin. Europe often refers to barrels as casks, especially when talking about alcohol strength, while in the US we favor “barrel-strength.”
Discover Wild Turkey’s collection of bourbons here
