Alcohol by volume
Alcohol by volume (abbreviated as ABV, abv, or alc/vol) 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.
In some countries, alcohol by volume is referred to as degrees Gay-Lussac (after the French chemist Joseph Louis Gay-Lussac).[4]
Contents |
Typical levels [edit]
Details about typical amounts of alcohol contained in various beverages can be found in the articles about individual drinks.
| Rectified spirit | 95%-96% |
Alcohol proof [edit]
Another way of specifying the amount of alcohol is alcohol proof, which in the United States is twice the alcohol-by-volume number,[7][8] while in the United Kingdom it is 1.75 times the number (expressed as a percentage). For example, 40% abv is 80 proof in the US and 70 proof in the UK. However, since 1980, alcoholic proof in the UK has been replaced by abv as a measure of alcohol content.
Proof and alcohol by weight [edit]
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. 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).[9] 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.
Calculation of alcohol content [edit]
During the production of wine and beer, yeast is added to a sugary solution. During fermentation, the yeast organisms consume the sugars and produce alcohol. The density of sugar in water is greater than the density of alcohol in water. A hydrometer is used to measure the change in specific gravity (SG) of the solution before and after fermentation. The volume of alcohol in the solution can then be calculated.
Wine [edit]
The simplest method for wine has been described by English author C.J.J. Berry:[10]
Beer [edit]
The calculation for beer is:
Where 1.05 is the number of grams of ethanol produced for every gram of CO2 produced, and .79 is the density of ethanol,
However, many brewers use the following formula:
See also [edit]
References [edit]
- ^ "Lafayette Brewing Co.". www.lafayettebrewingco.com. Retrieved 2012-02-04.
- ^ "Glossary of whisky and distillation". www.celtic-whisky.com. Retrieved 2012-02-04.
- ^ "English Ales Brewery Monterey British Brewing Glossary". www.englishalesbrewery.com. Retrieved 2012-02-04.
- ^ "Joseph Louis Gay-Lussac (1778–1850)". chemistry.about.com. Retrieved 2008-07-05.
- ^ Robinson, Jancis. The Oxford Companion to Wine, 3rd edition, (Oxford University Press: 2006). See alcoholic strength at p. 10.
- ^ Robinson, Jancis. The Oxford Companion to Wine, 3rd edition, (Oxford University Press: 2006). See fortification at p. 279.
- ^ C.J.J. Berry, 1987, First Steps in Winemaking, eighth edition, Special Interest Model Books Ltd, printed in UK
- ^ Regan, Gary (2003). The Joy of Mixology. New York: Clarkson Potter. pp. 356–357. ISBN 0-609-60884-3.
- ^ "Realbeer.com: Beer Break - Alcohol Content In Beer". www.realbeer.com. Archived from the original on 4 July 2008. Retrieved 2008-07-05.
- ^ Berry, C.J.J. (1987). First Steps in Winemaking. Poole, United Kingdom: Special Interest Model Books.
- ^ Anon, 2012, Industrial Microbiology Beer Fermentation Practical, School Of Applied Sciences, RMIT University, Melbourne
Bibliography [edit]
- 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.