Proof (prf)
Proof (prf) :
A traditional unit of proportion used for measuring the strength of distilled liquors, including medicinal solutions of alcohol as well as alcoholic beverages such as whiskey. The proof rating of a liquor is the alcohol content of the liquid expressed as a percentage of the alcohol content of a standard mixture, called the proof liquor. In the United States, the proof liquor is legally defined so to contain exactly 50% alcohol measured by volume. As a result, the U. S. proof rating is equal to exactly twice the percentage of alcohol present, measured by volume. Thus "86 proof" means 43% alcohol. In Britain proof ratings are no longer used, but the former proof liquor contained 57.27% alcohol by volume. This means that 86 proof Scotch, in the U.S., was formerly 75 proof in Britain
