In this series, we reveal the secrets, histories and quirky bits of trivia behind your favorite foods.
Do not try this at home: In a literal instance of trial by fire, British soldiers used to ignite rum in order to determine its alcohol content.
Back in the 1600s, soldiers in the British Navy were often paid in rum. Since there were no labeling regulations at the time, the sailors didn't know upon first glance whether their payment was actually water with a splash of alcohol or the good stuff. So they devised a clever system: They would mix the liquid with gunpowder and set it on fire. If it lit, it was "proof" that the solution contained a sufficient amount of alcohol; if not, the sailors knew they had been scammed.
While this system gave us the term "proof," which we still use to denote alcohol levels today, it wasn't the best method. Aside from the obvious explosive nature of the technique, it was also a waste of rum. Fortunately we have a much safer and more scientific way to measure alcohol levels today that results in both less rum waste and eyebrow hair singeing.
This summer, toast the seafaring rum-drinkers of the past with these rum-based cocktails—no pyrotechnics required or recommended.