It always struck me as odd, this idea of proof. It’s simply the doubling of the Alcohol by Volume (ABV) measure, so what’s the point? It doesn’t give us any useful information that ABV doesn’t, so why do we use it? I can tell you the answer in a word. Tradition!
Let’s take a journey back in time, back to when Pirates of the Caribbean were a people group, not a Disneyland attraction. Bit Coin was still in its infancy, so other means of payment had to be used. In our little slice of history, that payment was rum, proof that sometimes the old days really were the good old days. But how did you know you were getting the real deal and not some watered down version of 18th century near beer? Back in the days when Johnny Depp sailed the seven seas, sophisticated instruments like wikipedia had yet to be widely used, broadband being something of a hit-or-miss proposition on the sailing vessels of the time.
A simple test was developed, using what else but gunpowder and fire? Safety regulators were not impressed, but fortunately not invented yet. It was genius in its simplicity. Douse your bowl of gunpowder (you do have your bowl of gunpowder, right?) with the liquid in question and see if it would still burn. What could go wrong? If it did light up, that was . . . wait for it . . . PROOF of the alcohol’s suitability for killing your liver. Alcohol that did not pass this test was deemed too watered down and unfit for human consumption. It was labeled “Bud Light” and thrown overboard.
The minimum level of acceptable alcohol content was deemed 100 degrees of proof, which is why you will sometimes see it written as 100° proof.
A few years later, a meddler known only today as “Dr. Killjoy” decided lighting things on fire was no way to do things and used a new invention called “science” to determine that 100° proof equaled 57.15% ABV. “But wait,” I can hear you slur over that glass of whiskey in your hand, “That’s not double!” Congratulations, you can still do 3rd grade math! You can still have one more. At this point in our history, proof was indeed a curious math problem. Multiply ABV by 7/4 to arrive at proof. Simple!
In the 1980’s, just when the advent of the calculator watch would have made this all too easy, the European world decided it was silly and decided to just use ABV. Some old-school brands still reference the old proof system for olde tymes sake, but still list ABV as required by law.
Thumbing their nose at anything the French were involved in, the US decided to keep the proof idea, but simplify it because those buttons on the calculator watches were just too damn small. Hence, somewhere buried in a legal document hundreds of pages long that I refuse to read just for a footnote of attribution, is the idea that one may, if one so wishes, list proof as double ABV on one’s bottle, after also including ABV, of course.
So proudly talk of proof, if for no other reason than to show your support for needlessly lighting things on fire. It’s probably a good thing YouTube wasn’t around back then. “Watch me check the proof of dad’s cask-strength whiskey! Pass the gunpowder!”