Alcohol by volume
The International Organization of Legal Metrology has tables of density of water–ethanol mixtures at different concentrations and temperatures.
Mixing two solutions of alcohol of different strengths usually causes a change in volume.
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.
Volume fraction, which is widely used in chemistry (commonly denoted as v/v), is defined as the volume of a particular component divided by the sum of all components in the mixture when they are measured separately.
[citation needed] Low-alcohol beers (<0.5) are considered in some countries such as Iran as permitted (or "halal" under Muslim vocabulary) despite alcohol being banned.
[7] However, the level of alcohol-free beers is typically the lowest commercially sold 0.05.
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.
[9] 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.
[10][11] Details about typical amounts of alcohol contained in various beverages can be found in the articles about them.
(most juices do not have alcohol but orange or grape [the highest here] may have some from early fermentation) Under 2.5% in Finland, and 2.25% in Sweden, however.
During the production of wine and beer, yeast is added to a sugary solution.
A hydrometer is used to measure the change in specific gravity (SG) of the solution before and after fermentation.
There are a number of empirical formulae which brewers and winemakers use to estimate the alcohol content of the liquor made.
[citation needed] 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.
A general formula for calculating the resulting alcohol concentration by volume can be written: where SBV fermented is sugar by volume (g/dL) converted to alcohol during fermentation and GECF is the glucose-ethanol conversion factor: where 46.069 is the molar mass of ethanol and 180.156 is the molar mass of glucose and fructose.
The simplest method for wine has been described by English author Cyril Berry:[20]
This may lead to confusion over similar products bought in varying regions that have different names on country-specific labels.
[citation needed] In the United Kingdom, proof is 1.75 times the number (expressed as a percentage).
[citation needed] In the United States, Arkansas, Kansas, Mississippi, South Carolina, and Tennessee[24] regulate and tax alcoholic beverages according to alcohol by weight (ABW), expressed as a percentage of total mass.
