where did the term proof for alcohol come from
Alcohol proof The term proof dates back to 16th century England, when spirits were taxed at different rates depending on their alcohol content. Spirits were tested by soaking a pellet of gunpowder in them. If the gunpowder could still burn, the spirits were rated above proof and taxed at a higher rate.[1] As gunpowder would not burn if soaked in rum that contained less than 57.15% ABV, rum that contained this percentage of alcohol was defined as having 100 degrees proof.[2] The gunpowder test was officially replaced by a specific-gravity test in 1816.[1]