Alcohol by volume
Alcohol by volume is a common measure of the amount of alcohol contained in a given alcoholic beverage. It is defined as the volume the ethanol in the liquid would take if separated from the rest of the solution, divided by the volume of the solution, both at. Pure ethanol is lighter than water, with a density of. The alc/vol 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, e.g. France, alcohol by volume is often referred to as degrees Gay-Lussac, although there is a slight difference since the Gay-Lussac convention uses the International Standard Atmosphere value for temperature,.
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. The phenomenon of volume changes due to mixing dissimilar solutions is called "partial molar volume". Water and ethanol are both polar solvents. When water is added to ethanol, the smaller water molecules are attracted to the ethanol's hydroxyl group, and each molecule alters the polarity field of the other. The attraction allows closer spacing between molecules than is usually found in non-polar mixtures.Thus, alc/vol is not the same as volume fraction expressed as a percentage. Volume fraction, which is widely used in chemistry, is defined as the volume of a particular component divided by the sum of all components in the mixture when they are measured separately. For example, to make 100 mL of 50% alc/vol ethanol solution, water would be added to 50 mL of ethanol to make up exactly 100 mL. Whereas to make a 50% v/v ethanol solution, 50 mL of ethanol and 50 mL of water could be mixed but the resulting volume of solution will measure less than 100 mL due to the change of volume on mixing, and will contain a higher concentration of ethanol. The difference is not large, with the maximum difference being less than 2.5%, and less than 0.5% difference for concentrations under 20%.
Threshold levels
Legal thresholds
Some drinks have requirements of alcoholic content in order to be certified as a certain alcohol brand or label. For example, in the United Kingdom, the United States, Canada and European Union whisky is legally required to be no less than 40% ABV bottled.Low-alcohol beers are considered in some countries such as Iran as permitted despite alcohol being banned. However, the level of alcohol-free beers is typically the lowest commercially sold 0.05.
Biological thresholds
It is near impossible for a healthy person to become intoxicated drinking low-alcohol drinks. The low concentration severely limits the rate of intake, which is easily dispatched by human metabolism. Quickly drinking 1.5 L of 0.4% alc/vol beer in an hour resulted in a maximum of 0.0056% BAC in a study of German volunteers. Healthy human kidneys can only excrete 0.8-1.0 L of water per hour, making water intoxication likely to set in before any alcoholic intoxication.The process of ethanol fermentation will slow down and eventually come to a halt as the alcohol produced becomes too concentrated for the yeast to tolerate, defining an upper limit of alc/vol for non-distilled alcoholic drinks. The typical tolerance for beer yeasts is at 8-12%, while wine yeasts typically range from 14-18%, with speciality ones reaching 20% alc/vol. Any higher would require distillation, producing liquor.
Typical levels
Details about typical amounts of alcohol contained in various beverages can be found in the articles about them.| Drink | Typical alc/vol | Lowest | Highest |
| Fruit juice | 0–0.11% They qualify as alcohol-free drinks in most countries. | 0.00 | 0.11 |
| Low-alcohol beer | 0.05–1.2% Under 2.5% in Finland, and 2.25% in Sweden, however. | 0.05 | 1.02 |
| Kvass | 0.05–1.5% | 0.05 | 1.50 |
| Kefir | 0.2–2.0% | 0.20 | 2.00 |
| Sobia | 0.2–6.8% | 0.20 | 6.80 |
| Kombucha | 0.5–1.5% | 0.50 | 1.50 |
| Kumis | 0.7–4.5% | 0.70 | 4.50 |
| Boza | 1.0% | 1.00 | 1.00 |
| Chicha | 1.0–11% | 1.00 | 11.00 |
| Tubâ | 2.0–4.0% | 2.00 | 4.00 |
| Chūhai | 3.0–12.0% | 3.00 | 12.00 |
| Pulque | 2.0–7.0% | 2.00 | 12.00 |
| Beer | 2.00 | 10.00 | |
| Cider | 4.00 | 8.00 | |
| Palm wine | 4.0–6.0% | 4.00 | 6.00 |
| Alcopops | 4.0–17.5% | 4.00 | 17.50 |
| Malt liquor | 5.0-9.0% | 5.00 | 9.00 |
| Hard seltzer | 5.0% | 5.00 | 5.00 |
| Four Loko | 6–14% | 6.00 | 14.00 |
| Makgeolli | 6.5–7% | 6.50 | 7.00 |
| Kuchikamizake | 7% | 7.00 | 7.00 |
| Barley wine | 8–15% | 8.00 | 15.00 |
| Mead | 8–16% | 8.00 | 16.00 |
| Wine | 5.5–16% | 5.50 | 16.00 |
| Bahalina | 10–13% | 10.50 | 13.00 |
| Basi | 10–16% | 10.00 | 16.00 |
| Bignay wine | 12–13% | 12.00 | 13.00 |
| Duhat wine | 12–13% | 12.00 | 13.00 |
| Tapuy | 14–19% | 14.00 | 19.00 |
| Kilju | 15–17% | 15.00 | 17.00 |
| Dessert wine | 14–25% | 14.00 | 25.00 |
| Sake | 15% | 15.00 | 20.00 |
| Liqueurs | 15–55% | 15.50 | 55.00 |
| Fortified wine | 15.5–20% | 15.50 | 22.00 |
| Soju | 14–45% | 14.00 | 45.00 |
| Rice wine | 18–25% | 18.00 | 25.00 |
| Shochu | 25–45% | 25.00 | 45.00 |
| Awamori | 25–60% | 25.00 | 60.00 |
| Rượu đế | 27–45% | 27.00 | 45.00 |
| Bitters | 28–45% | 28.00 | 45.00 |
| Applejack | 30–40% | 30.00 | 40.00 |
| Pisco | 30–48% | 30.00 | 48.00 |
| Țuică | 30–65% | 30.00 | 65.00 |
| Mezcal, Tequila | 32–60% | 32.00 | 60.00 |
| Vodka | 35–95% | 35.00 | 95.00 |
| Rum | 37.5–80% | 37.50 | 80.00 |
| Brandy | 35–60% | 35.00 | 60.00 |
| Grappa | 37.5–60% | 37.50 | 60.00 |
| Ouzo | 37.5% | 37.50 | 37.50 |
| Aquavit | 37.5–40% | 37.50 | 40.00 |
| Gin | 37.5–50% | 37.50 | 50.00 |
| Pálinka | 37.5–86% | 37.50 | 86.00 |
| Cachaça | 38–48% | 38.00 | 48.00 |
| Sotol | 38–60% | 38.00 | 60.00 |
| Stroh | 38–80% | 38.00 | 80.00 |
| Fernet | 39–45% | 39.00 | 45.00 |
| Feni | 40–42.5% | 40.00 | 42.50 |
| Lambanog | 40–45% | 40.00 | 45.00 |
| Nalewka | 40–45% | 40.00 | 45.00 |
| Tsipouro | 40–45% | 40.00 | 45.00 |
| Rakı | 40–50% | 40.00 | 50.00 |
| Scotch whisky | 40–70+% | 40.00 | 70.00+ |
| Whisky | 40–70+% | 40.00 | 70.00+ |
| Baijiu | 40–65% | 40.00 | 65.00 |
| Chacha | 40–70% | 40.00 | 70.00 |
| Bourbon whiskey | min 40% bottled | 40.00 | 80.00 |
| Rakija | 40–86% | 42.00 | 86.00 |
| Maotai | 43–53% | 43.00 | 53.00 |
| Absinthe | 45–89.9% | 45.00 | 89.90 |
| Arak | 60–65% | 60.00 | 65.00 |
| Oghi | 60–75% | 60.00 | 75.00 |
| Poitín | 60–95% | 60.00 | 95.00 |
| Centerbe | 70% | 70.00 | 70.00 |
| Neutral grain spirit | 85–95% | 85.00 | 95.00 |
| Cocoroco | 93–96% | 93.00 | 96.00 |
| Rectified spirit | 95% up to a practical limit of 97.2% | 95.00 | 97.20 |
Practical estimation 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 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.Specific gravity is the density of a liquid relative to that of water, i.e., if the density of the liquid is 1.05 times that of water, it has a specific gravity of 1.05. In UK brewing usage, it is customary to regard the reference value for water to be 1000, so the specific gravity of the same example beer would be quoted as 1050. The formulas here assume that the former definition is used for specific gravity.