The Proof is double the ABV...so yes 30% ABV would be called 60 Proof.
So What is Proof?
Distillation, if repeated to the ultimate, will result in a liquid which is pure alcohol or “200 proof.” The proof number is twice the actual alcoholic content of the liquid expressed as a percentage. Thus “100 proof” rum contains 50% alcohol, or “80 proof” whiskey means the bottle contains 40% alcohol. The word “proof” used to be the only way that the alcoholic content of liquor in the U.S. was described, and the term is still widely spread.
There is an interesting history behind the usage and definition of “proof.” In Britain, skeptical buyers needed a way to test or prove the quality of the liquor they were purchasing. They developed a testing method that required the liquid to be mixed with gunpowder. The mixture was then held over a flame. The gunpowder ignited only when the percentage of alcohol in the liquid was 50% or better. So the liquor was considered entirely “proved” when its alcoholic content was at least 50%.
Outside of the U.S., most other countries no longer measure alcohol content by proof, but use a measurement called ABV, or “alcohol by volume”, also known as the Gay-Lussac system. The alcohol content is stated as a percentage of the total liquid, so a 40% ABV spirit contains 40% alcohol. Since liquor is sold internationally, most labels now will list both ABV and Proof.
While a few liquors, especially some rums, are bottled at higher than 100 proof (50% ABV) - most liquor is 80 proof (40% ABV). However, you do need to note the proof when consuming any new spirit with which you’re unfamiliar. Many manufacturers make different proofs using similar labels, which may not always make the difference evident. The Bacardi web site, for example, describes its Bacardi 151 brand as “one that lives on the wild side” but doesn’t ever actually state that the name “151” means it’s 151% proof or 75% ABV.
So What is Proof?
Distillation, if repeated to the ultimate, will result in a liquid which is pure alcohol or “200 proof.” The proof number is twice the actual alcoholic content of the liquid expressed as a percentage. Thus “100 proof” rum contains 50% alcohol, or “80 proof” whiskey means the bottle contains 40% alcohol. The word “proof” used to be the only way that the alcoholic content of liquor in the U.S. was described, and the term is still widely spread.
There is an interesting history behind the usage and definition of “proof.” In Britain, skeptical buyers needed a way to test or prove the quality of the liquor they were purchasing. They developed a testing method that required the liquid to be mixed with gunpowder. The mixture was then held over a flame. The gunpowder ignited only when the percentage of alcohol in the liquid was 50% or better. So the liquor was considered entirely “proved” when its alcoholic content was at least 50%.
Outside of the U.S., most other countries no longer measure alcohol content by proof, but use a measurement called ABV, or “alcohol by volume”, also known as the Gay-Lussac system. The alcohol content is stated as a percentage of the total liquid, so a 40% ABV spirit contains 40% alcohol. Since liquor is sold internationally, most labels now will list both ABV and Proof.
While a few liquors, especially some rums, are bottled at higher than 100 proof (50% ABV) - most liquor is 80 proof (40% ABV). However, you do need to note the proof when consuming any new spirit with which you’re unfamiliar. Many manufacturers make different proofs using similar labels, which may not always make the difference evident. The Bacardi web site, for example, describes its Bacardi 151 brand as “one that lives on the wild side” but doesn’t ever actually state that the name “151” means it’s 151% proof or 75% ABV.
