Drinks can have some pretty interesting terminology attached to them. However, one of the easier-to-understand terms out there is alcohol proof. While it’s quite a common term nowadays, it can still be a bit confusing if you don’t understand where it comes from, and how other places interpret it…

Alcohol Proof: What Does It Mean?

Definition and origin

Alcohol proof refers to how much alcohol is in a liquor. That’s seems pretty simple, so why the somewhat-odd name? After all, you might think it’s easier to call it alcohol content or something similar. In order to understand why it’s called proof, you have to go back and look at 16th century English alcohol laws.

Back then, England taxed liquors by their alcohol levels. However, the tax collectors couldn’t just measure the levels, as they didn’t have the technology we have now. Instead, the collectors soaked a pellet of gunpowder in the liquor, and if it could still burn, then it was “proof” of a high alcohol level. As a result of this test (which collectors used until 1816), the name eventually stuck.

Differing standards

While alcohol proof might have gotten it’s name from England, it still can mean different things in different places. In fact, most nations determine proof in different ways. For example, the U.S. makes use of the “doubling” system. An alcohol’s proof is usually always double of what it’s actual ABVlevel is.

However, in England, they only use ABV levels. The same goes for nations within the European Union. That means that you might not even see proof labels at all. If you do, then they might be the same as the ABV. Keep this in mind if you’re drinking abroad!

Related terms

There are a couple other alcohol proof related terms that you’ll want to keep in mind. Cask strength, for example, means the proof is the same as when the liquor was in its cask. You may also hear barrel strength or proof, but don’t worry; they mean the same as cask strength.

There’s also Navy proof, or overproof. Usually reserved for gin or rum, this label just means that the liquor has a high ABV, usually around 57%. There’s also single cask, or double barrel labels. However, don’t let these confuse you. They just refer to how the liquor was stored or blended rather than its alcohol content.