Alcohol by volume

"ABV" redirects here. For other uses, see ABV (disambiguation).

The alcohol by volume shown on a bottle of absinthe.

Alcohol by volume (abbreviated as ABV, abv, or alc/vol) is a standard measure of how much alcohol (ethanol) is contained in a given volume of an alcoholic beverage (expressed as a volume percent).^[1]^[2]^[3] It is defined as the number of millilitres of pure ethanol present in 100 millilitres (3.4 US fl oz) of solution at 20 °C (68 °F). The number of millilitres of pure ethanol is the mass of the ethanol divided by its density at 20 °C, which is 0.78924 g/ml. The ABV standard is used worldwide. The International Organization of Legal Metrology has tables of density of water–ethanol mixtures at different concentrations and temperatures.

In some countries, such as the U.K and France, alcohol by volume is referred to as degrees Gay-Lussac (after the French chemist Joseph Louis Gay-Lussac),^[4] although there is a slight difference since Gay-Lussac used 15 °C (59 °F). This results in the slight difference in marked % noted later in this article.

Volume change

Mixing two solutions of alcohol of different strengths usually causes a change in volume. Mixing pure water with a solution less than 24% by mass causes a slight increase in total volume, whereas the mixing of two solutions above 24% causes a decrease in volume.^{[lower-alpha 1]} The phenomenon of volume changes due to mixing dissimilar solutions is called "partial molar volume".

Typical levels

Details about typical amounts of alcohol contained in various beverages can be found in the articles about them.

Drink	Typical ABV
Fruit juice (naturally occurring)	less than 0.1%
Low-alcohol beer	0.05%–1.2%
Kvass	0.05%–1.5%
Kefir	0.2%–2.0%
Kombucha	0.5%–1.5%
Boza	1%
Chicha	1%–11% (usually 1%–6%)
Cider	2%–8.5%
Beer	2%–12% (usually 4%–6%)
Alcopops	4%–17.5%
Malt liquor	5%+
Makgeolli	6.5%–7%
Barley wine (strong ale)	8%–15%
Mead	8%–16%
Wine	9%–16% (most often 12.5%–14.5%)^[5]
Kilju	15%–17%
Dessert wine	14%–25%
Sake (rice wine)	15% (or 18%–20% if not diluted prior to bottling)
Liqueurs	15%–55%
Fortified wine	15.5%–20%^[6] (in the European Union, 18%–22%)
Soju	17%–45% (usually 19%)
Shochu	25%–45% (usually 25%)
Ruou (Vietnamese liquor)	27%-45% (usually 35%- except Ruou tam -40-45%)
Bitters	28%–45%
Applejack	30%-40%
Mezcal, Tequila	32%–60% (usually 40%)
Vodka	35%–50% (usually 40%, minimum of 37.5% in the European Union)
Brandy	35%–60% (usually 40%)
Grappa	37.5%–60%
Rum	37.5%–80%
Ouzo	37.5%+
Cachaça	38%–54%
Sotol	38%–60%
Stroh	38%–80%
Nalewka	40%–45%
Gin	40%–50%
Whisky	40%–68% (usually 40%, 43% or 46%)
Baijiu	40%–60%
Chacha	40%–70%
Centerbe (herb liqueur)	70%
Pálinka	42%–86% (legally in Hungary 48%–51%)
Rakia	42%–86%
Absinthe	45%–89.9%
Ţuica	45%–60% (usually 52%)
Arak	60%–65%
Poitín	60%–95%
Neutral grain spirit	85%–95%
Cocoroco	93%–96%
Rectified spirit	95%–96%

Alcohol proof

Another way of specifying the amount of alcohol is alcohol proof, which in the United States is twice the alcohol-by-volume number, while in the United Kingdom it is 1.75 times the number (expressed as a percentage).^[7]^[8] 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.

Alcohol by volume 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. Some brewers print the ABW (rather than the ABV) on beer containers, particularly on low-point versions of popular domestic beer brands.

One can use the following equation to convert between ABV and ABW:

ABV\times 0.78924=ABW\times {\text{density of beverage at 20°C in g/ml}}

At relatively low ABV, the alcohol percentage by weight is about 4/5 of the ABV (e.g., 3.2% ABW is about 4% 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.

Prediction of alcohol content

During the production of wine and beer, yeast is added to a sugary solution. During fermentation, the yeasts 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 estimated. There are a number of empirical formulae which brewers and winemakers use to estimate the alcohol content of the liquor made.

Wine

The simplest method for wine has been described by English author C.J.J. Berry:^[8]

$ABV=(\mathrm {Starting~SG} -\mathrm {Final~SG} )/7.36$

Beer

Main article: Beer measurement § Strength

The calculation for beer is:^[10]

$ABV=133.62\times \left(\mathrm {Starting~SG} -\mathrm {Final~SG} \right)$

However, many brewers use the following formula which uses a different constant (different probably due to temperature variations and rounding):^[11]

$ABV=131.25\left(\mathrm {Starting~SG} -\mathrm {Final~SG} \right)$

It is derived in this manner:^[10]

$ABV={\frac {\rho _{C2H5OH}}{\rho _{CO2}}}\times {\frac {\rho _{H2O}}{\rho _{C2H5OH}}}\times {\frac {\rho _{CO2}}{\rho _{H2O}}}\times 100$
$ABV={\frac {\rho _{C2H5OH}}{\rho _{CO2}}}\times {\frac {\rho _{H2O}}{\rho _{C2H5OH}}}\times {\frac {\rho _{OG}-\rho _{FG}}{\rho _{H2O}}}\times 100$
$ABV={\frac {\rho _{C2H5OH}}{\rho _{CO2}}}\times {\frac {\rho _{H2O}}{\rho _{C2H5OH}}}\times \left(\mathrm {Starting~SG} -\mathrm {Final~SG} \right)\times 100$
$ABV={\frac {46.0684}{44.0095}}\times {\frac {1.0}{0.78934}}\left(\mathrm {Starting~SG} -\mathrm {Final~SG} \right)\times 100$
$ABV={\frac {1.04678}{0.78934}}\times \left(\mathrm {Starting~SG} -\mathrm {Final~SG} \right)\times 100$
$ABV=133.62\times \left(\mathrm {Starting~SG} -\mathrm {Final~SG} \right)$

1.05 is the ratio of ethanol molecules produced for every molecule of CO₂ produced (46.07 g/mol C2H6O / 44.01 g/mol CO2 = 1.0468) from a single molecule of glucose. The number 0.7936 is the specific gravity of a 100% ethanol solution^[12]. Both are unit-less measurements. The difference between the starting SG and the final SG measures the specific gravity lost to CO₂ release.

For higher ABV above 6% many brewers use this formula:^[13]

$ABV={\frac {1.05}{0.79}}\left({\frac {\mathrm {Starting~SG} -\mathrm {Final~SG} }{\mathrm {Final~SG} }}\right)\times 100$

References

↑ See data in the CRC Handbook of Chemistry and Physics, 49th edition, pp. D-151 and D-152. Mixing a solution above 24% with a solution below 24% may cause an increase or a decrease, depending on the details.

↑ "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 2006, p. 10.
↑ Robinson 2006, p. 279.
↑ Regan 2003.
1 2 Berry 1998.
↑ "Alcohol Content In Beer". www.realbeer.com. Archived from the original on 4 July 2008. Retrieved 2008-07-05.
1 2 "Calculate Percent Alcohol in Beer". BrewMoreBeer.com. Retrieved 2014-07-03.
↑ "Get to Know Your Alcohol (By Volume)". BeerAdvocate.com. Retrieved 2014-07-03.
↑ "S.G. Table for Ethanol-Water". www.separationprocesses.com. Retrieved 2016-08-31.
↑ Anon, 2012, Industrial Microbiology Beer Fermentation Practical, School Of Applied Sciences, RMIT University, Melbourne

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.
Berry, C. J. J. (1998). First Steps in Winemaking. Nexus Special Interests. ISBN 978-1-85486-139-9.
Regan, Gary (2003). The Joy of Mixology. Clarkson Potter. ISBN 978-0-609-60884-5.
Robinson, Jancis (2006). The Oxford Companion to Wine (3rd ed.). Oxford: OUP. ISBN 978-0-19-860990-2.

External links

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