Alcohol proof is a measure of how much alcohol (ethanol) is
contained in an alcoholic beverage. The term was originally used
in the United Kingdom and was defined as 7/4 times the alcohol
by volume (ABV). The UK now uses the ABV standard instead of
alcohol proof. In the United States, alcoholic proof is defined
as twice the percentage of ABV. The measurement of alcohol
content and the statement of this content on the bottle labels
of alcoholic beverages is regulated by law in the United States.
The purpose of the regulation is to provide pertinent
information to the consumer. ||This section needs additional
citations for verification. (April 2013)| From the 18th century
until 1 January 1980, the UK measured alcohol content in terms
of "proof spirit", which was defined as spirit with a gravity of
12/13 that of water, or 923kg/m3, and equivalent to 57.15% ABV.
The term originated in the 18th century, when payments to
British sailors included rations of rum. To ensure that the rum
had not been watered down, it w