# Alcohol by volume: Wikis

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

### Did you know ...

More interesting facts on Alcohol by volume

# Encyclopedia

The ABV declaration on a bottle of absinthe.

Alcohol by volume (abbreviated as abv or ABV) is a standard measure of how much alcohol (ethanol) is contained in an alcoholic beverage (expressed as a percentage of total volume).[1][2][3] The ABV standard is used worldwide.[4]

In some countries, alcohol by volume is referred to as degrees Gay-Lussac (after the French chemist Joseph Louis Gay-Lussac).[5]

## Calculating

In the brewing process, yeast is added to a sugary solution (usually fruit juice or malted barley) where over fermentation the yeast organisms consume the sugars and produce alcohol. The density of sugar in water is lower than the density of alcohol, therefore by using a hydrometer to measure the specific gravity (SG) of the solution before and after fermentation, the volume of alcohol in the solution may be calculated. The simplest method has been described by C.J.J. Berry [6].

ABV = (Startin gSGFinalSG) / 7.36

To convert alcohol by volume to per cent proof, multiply by 7-4ths. [7]

## Proof and ABV

Another way of specifying the amount of alcohol is alcoholic proof, which in the United States is twice the alcohol-by-volume number.[10]

## Proof and alcohol by weight

In the United States, a few states regulate and tax alcoholic beverages according to alcohol by weight (ABW), expressed as a percentage of total mass.[11] Some brewers print the ABW (rather than the ABV) on beer containers, particularly on low-point versions of popular domestic beer brands.

At relatively low ABV, the alcohol percentage by weight is about 4/5 of the ABV (e.g., 3.2% ABW is equivalent to 4.0% ABV).[12] However, because of the miscibility of alcohol and water, the conversion factor is not constant but rather depends upon the concentration of alcohol. 100% ABW, of course, is equivalent to 100% ABV.

## References

### Notes

1. ^ "Lafayette Brewing Co. Beer Terms". www.lafayettebrewingco.com. Retrieved 2008-07-05.
2. ^ "Glossary of whisky and distillation". www.celtic-whisky.com. Retrieved 2008-07-05.
3. ^ "English Ales Brewery Monterey British Brewing Glossary". www.englishalesbrewery.com. Retrieved 2008-07-05.
4. ^ "Frequently Asked Questions - CAMRA". www.camra.org.uk. Retrieved 2008-07-05.
5. ^ "Joseph Louis Gay-Lussac (1778–1850)". chemistry.about.com. Retrieved 2008-07-05.
6. ^ C.J.J. Berry, 1987, First Steps in Winemaking, eighth edition, Special Interest Model Books Ltd, printed in UK
7. ^ C.J.J. Berry, 1987, First Steps in Winemaking, eighth edition, Special Interest Model Books Ltd, printed in UK
8. ^ Robinson, Jancis. The Oxford Companion to Wine, 3rd edition, (Oxford University Press: 2006). See alcoholic strength at p. 10.
9. ^ Robinson, Jancis. The Oxford Companion to Wine, 3rd edition, (Oxford University Press: 2006). See fortification at p. 279.
10. ^ Regan, Gary (2003). The Joy of Mixology. New York: Clarkson Potter. pp. 356–357. ISBN 0-609-60884-3.
11. ^ "APIS - Alcohol Beverages Taxes: Flavored Alcoholic Beverages". www.alcoholpolicy.niaaa.nih.gov. Retrieved 2008-07-05.
12. ^ "Realbeer.com: Beer Break - Alcohol Content In Beer". www.realbeer.com. Retrieved 2008-07-05.

### Bibliography

• Hehner, Otto (1880). Alcohol Tables: giving for all specific gravities, from 1.0000 to 0.7938, the percentages of absolute alcohol, by weight and volume. London: J & A Churchill, ASIN B0008B5HOU.