It is a way to check sobriety. If you are unable to divide the proof by 2 and get the alcohol content its either time to stop drinking or go back to school.
100% pure alcohol is 200 proof. A liquid containing 10.5% alcohol would thus be 21 proof
The answer varies in each different liquor, and should be listed on the bottle as "proof". The "Proof" is twice the alcohol percentage, so 40 proof is 20% alcohol, 180 proof is 90% alcohol.
In the United States, the alcohol-by-volume proof measurement equates to twice the percentage of alcohol content. If a beverage contains 28% alcohol by volume, it would be considered to be 56 proof.
"Proof" means the accumulation of evidence which brings you to the conclusion that a statement is true. "Proof" also is a way of measuring alcohol content of spirits, being twice the percentage of alcohol in the spirit.
151/2 = 75.5% try not to drink too much, as this contains nearly twice as much alcohol per shot as vodka and more than twice that of most rums.
In the U.S., proof equals twice the percentage of alcohol in the beverage. In the UK, and several European countries, the 'proof' of alcohol is not given, it is stated as a percentage of volume. However this is somewhat misleading. Pure alcohol, which would be 100% alcohol, very difficult to produce, would be classed as 200 proof. Confusing to the uninitiated. All spirit drinks sold retail in the UK must state their alcohol by volume and not their 'proof'.
"Alcoholic proof is a measure of how much alcohol (i.e., ethanol) is contained in an alcoholic beverage. The measure is commonly used in the United States, where it is defined as twice the percentage of alcohol by volume."Source: http://en.wikipedia.org/wiki/Alcoholic_proof
The "Proof" of an alcoholic beverage is an indicator of it's alcohol content on a 200 point scale. Take the Proof # and divide it by 2 to find out what the percentage is. So, to answer you specific question, 86/2= 43. Therefore 86 proof alcohol is 43 percent alcohol.
In the United States, the "proof" descriptor for a bottle of liquor is defined as twice the percentage of alcohol by volume. Thus, a bottle labeled as "100 proof" will consist of 50% alcohol-content.
Depends on where you go - it generally goes by ABV or "proof". ABV is pretty much understood everywhere since it gives a general measure of how much alcohol is in the beverage by volume. e.g. a pint of beer in the US at 5% ABV will yield about 0.6 US fluid ounces of alcohol.
The proof number is twice the percentage of the alcohol content measured by volume, Therefore '80 proof' is 40% alcohol by volume.The measure of the percentage of alcohol in drinks is widely believed to have started in the 18th century, when alcohol and gunpowder would be mixed together, if the combination lit when a flame was applied, it would be considered to have 'proved' it was a strong alcohol. (This is where the term 'firewater' is believed to have come from.) Originally that was considered 100 proof and was actually 50% alcohol, but more sophisticated measures since then have established that this alcohol and gunpowder mix would ignite if there was at least 57% alcohol, not 50%.
Quote from the Related Link: "What does proof mean when it refers to whiskey (and other distilled alcoholic beverages), and where did the term come from? Well, first here is the modern definition: proof is twice the percentage of alcohol by volume. Therefore, 100 proof is 50% alcohol. 200 proof is 100% alcohol."