Full Proof Versus Barrel Proof

December 2, 2024 –––––– Jake Emen, , , ,

Barrel proof and cask strength are interchangeable terms indicating that the content of a bottled whiskey matches that of the liquid when it finishes maturation. No water is added to bring the product down to a specific, targeted strength. But what about “full proof,” a term that’s gaining traction but does not seem to have as clear of a definition? It seems that full proof isn’t quite so “foolproof” at all.

What Does Full Proof Mean?

Well, that depends on who you ask. “Full proof” isn't defined or regulated in any way by the U.S. Tax and Trade Bureau, and thus a producer can choose to apply it however it chooses. This is similar to how terms such as “small batch” lack a definitive meaning, and are therefore open to interpretation and misinterpretation.

Buffalo Trace uses the term full proof in a very specific way, and perhaps due to whiskey lovers’ fascination with everything the distillery produces, many fans have taken its application to be the standard. “We use the term ‘full proof’ to specify that [the whiskey is the same] proof [as when it] went into the barrel, versus ‘barrel proof’ being whatever exits the barrel after aging,” says master distiller Harlen Wheatley.

W.L. Weller Full Proof enters the barrel at 57% ABV, and after maturation, is recalibrated [water added] so that it ends up in the bottle at the same strength. Barton 1792 Distillery, sister distillery to Buffalo Trace (both are owned by Sazerac), uses the term in the same way as Buffalo Trace for products like its 1792 Full Proof bourbon. For Wheatley, releasing a product at full proof, indicating barrel entry proof, alters the emphasis in an intriguing way. “The goal with Weller Full Proof was to show people how the flavor changes during the aging process and focus on that, rather than how the proof changes in the barrel,” he says. “It focuses on the flavor that was created.”

That’s not how the term is always used, though. “There are a handful of producers whom we’ve noticed using the term full proof, and the perception is a mixture of people who think it’s cask strength, or high proof, and people who think it’s the entry proof,” says Barrell Craft Spirits (BCS) founder Joe Beatrice. BCS hasn’t deployed the term itself, partially because it incorporates barrels with a variety of entry proofs, and partly because it’s aware of the potential for confusion. “The average drinker may not be aware of the subtlety of the different terms, they probably assume they’re all the same, which is one of the reasons we have stayed with cask strength on our products,” Beatrice says. “It conveys a clear message.”

Dave Schmier, founder of independent bottler Proof and Wood, points out that even barrel strength isn’t a regulated term, though it does have an agreed upon—and perhaps obvious—definition. As for full proof, he takes it not to mean barrel entry proof, but rather, simply a higher or fuller proof. “I believe it has no real legal meaning, but it’s often used for high-proof batches of whiskey,” he says. “It allows for a uniform proof, so a producer could have a product that is always 110 proof, adding more consistency than having different batches at different proofs.” Schmier's personal expectation would be that something labeled as “full proof” would be a minimum of 105 proof. However, he hasn't used the term for any of his whiskeys.

Green River Distilling Co., now owned by Bardstown Bourbon Company, released a Full Proof bourbon in 2024 with its own spin on the lingo. The release is bottled at what the distillery also describes as “variable batch-proof,” though it opted against using such terminology for its moniker.

“The term ‘full proof’ resonates as the best expression for what we are creating, as we are using small batches of barrels, it is not an individual barrel proof, it is the full proof of the batch,” says Dan Callaway, vice president of product development. “We use full proof to represent the authentic, full-flavored version of the bourbon. Each batch has its own characteristic flavor to enjoy.”

Of course, Callaway recognizes that the way he’s using the term isn’t the way everyone else does. “It’s interesting to see how full proof is used, and it can denote that the whiskey was proofed to the original barrel-entry proof,” he says.

If the producers themselves have this much variance in how they define and use such terms, surely it’s even trickier for us whiskey drinkers trying to make sense of it all. Therefore, make sure to assess bottles from different distilleries and brands on a case-by-case basis. “Consumers should be aware of the labeling as always and consider what they prefer,” Wheatley says.

“The best way to stay informed is to ask,” Callaway says. “We love engaging with our fans and talking about our expressions.”

Barrel Proof and Full Proof Whiskeys to Try

94 Bernheim Original Barrel Proof Bourbon (Batch A224), 62.6%, $65

The palate is powerful, but holds its high proof very well—nothing at all jagged or harsh about it—with flavors of baked apple, orange peel, musty aged oak, chocolate fudge, and vanilla.

94 Wild Turkey Rare Breed Barrel Proof Straight Rye, 56.1%, $60

Zesty mint, eucalyptus, pine, and cedar chest mingle with sliced orange, candied strawberry, and sweet pecans mingle with nutty, spiced, herbaceous, and citrus-sweet flavors.

93 Larceny Barrel Proof Bourbon (Batch A124), 62.1%, $65

The palate is spicy and powerful at first but mellows quickly, revealing chocolate cake, cinnamon, baking spice, and cherry pie.

93 Weller Full Proof Bourbon, 57%, $50

A rich symphony of flavor punctuates the long, impressive finish—mocha, almond, and cooked dark fruit, draped in notes of gooey caramel and pepper spice, set against balanced oak.

92 1792 Full Proof Bourbon, 62.5%, $45

A pleasingly sweet bourbon, with caramel, nougat, and chewy toffee, mixed with ripe orchard fruit, golden raisin, and creamy vanilla.

92 Elijah Craig Barrel Proof Bourbon (Batch C923), 66.5%, $75

Sweet, but quite powerful and herbal on the palate, with lots of heat as spiced oak and drying tannins temper vanilla and dark fruit. A flavorful powerful whiskey as always, whose high ABV might not be for everyone, but with ice and/or water, the flavors abound.