Proof? Proof of what? |
In America, the potency of alcohol is measured in degrees of
proof. Proof measures the amount of alcohol within spirits, a measure
that runs from 0 to 200. 0 proof would be absolutely free of alcohol; 100
proof would be half alcohol; 200 proof would be pure alcohol. But why
200?
This dates back to 16th century England, when
spirits were taxed differently according to the amount of alcohol in
them. Tax collectors would perform a test to determine how much alcohol
was in particular spirits. To conduct the test, a pellet of gunpowder would be
soaked in the spirit, then removed to see if it would still burn. If the
pellet burned after being soaked in rum, it was said to be “100 degrees proof”,
and higher taxes were levied on it.
The proof test was applied to other spirits, but rum was the
one that was used to set the standard. At this time, there was no such
thing as “200 proof”. The English scale in the 16th century
went up to 175. Chemists knew that rum that was 4/7 alcohol would burn,
so that’s where the “100 degrees” measure came from. “100 degrees”
worked out to 57.14% alcohol.
In 1816, England replaced the gunpowder test with a
chemistry test, but kept the confusing math. In 1848, the United States
developed its simplified system where “100 proof” means “50% alcohol”.
The term proof, incidentally, derives from the Middle
English word preove, which means to test. Since this was a
test to determine the strength of alcohol, it was a proof. In the
modern sense, proof is another word for evidence, and to prove
something means to provide evidence. This old sense of the word
lives on in this alcohol test, and also in the expression “the exception that
proves the rule”. If we were to update that expression, we’d say “the
exception that tests the rule” or “the exception that challenges the rule”, but
old habits die hard. So do hangovers.
Comments