Everything about Proof Alcohol totally explained
Alcoholic proof is a measure of how much
ethanol is in an
alcoholic beverage, and is approximately twice the percentage of
alcohol by volume (
ABV, the unit that's commonly used at present).
Regulations
EU
The
European Union follows the recommendation of the
International Organization of Legal Metrology (OIML) which states percentage of alcohol by volume (ABV) at 20 °C.
British proof spirits
Britain originally specified alcohol content in terms of proof spirit, originally defined as the most dilute spirit which would sustain combustion of gunpowder.
In this system, spirit of 100 degrees proof contains 57.1% alcohol by volume or 49.28% alcohol by weight at 51 °F (10.6 °C) and is equivalent to 114.2 proof in the USA. Pure ethanol is 175.25 degrees proof, or more strictly is 75.25 degrees over proof.
From the 1740s until 1816 Customs and Excise and
London brewers and distillers used
Clarke's hydrometer to measure proof. From 1816 the
Sikes hydrometer was used to measure degrees proof. Officially the
Customs and Excise Act of 1952 defined "spirits of proof strength" (or proof spirits):
» "
Spirits shall be deemed to be at proof if the volume of the ethyl alcohol contained therein made up to the volume of the spirits with distilled water has a weight equal to that of twelve-thirteenths of a volume of distilled water equal to the volume of the spirits, the volume of each liquid being computed as at fifty-one degrees Fahrenheit."
Britain now uses the EU ABV standard.
United States
In the
United States of America too, alcohol content is stated as ABV. US Federal regulation (CFR 27 5.37 Alcohol Content) requires that liquor labels state the percentage of alcohol by volume (sometimes abbreviated ABV). The regulations permit but don't require a statement of the degrees of proof as long as it's printed close to the percentage of alcohol by volume.
The
degrees of proof is twice the percentage of the alcohol content measured by
volume at a temperature of 60
°F (15.5
°C). Therefore "80 proof" is 40% alcohol by volume, and pure alcohol is "200 proof". US proof differs significantly from British proof.
Levels of alcohol during liquor production
Alcohol is produced by
yeast during the process of
fermentation. The amount of alcohol in the finished liquid depends on how much sugar there was at the beginning for the yeast to convert into alcohol. In beer, the alcohol is generally 3% to 12% (6 to 24 US proof) and usually about 4% to 6% (8 to 12 US proof). Depending on the strain of yeast, wines top out at about 14% to 16% (28 to 32 US proof), because that's the point in the fermentation process where the alcohol concentration denatures the yeast. Since the 1990s, a few alcohol-tolerant 'superyeast' strains have become commercially available, which can ferment up to 20%.
(External Link
)
Fortified wines, such as sweet and dry vermouths become fortified by adding alcohol. These added alcohols are typically distilled wines such as brandy, port, sherry, marsala, and madeira. This second source of alcohol is added before the wines are finished fermenting, as the added alcohol kills the yeast in fermenting wine, leaving an abundance of sugar.
Stronger liquors are
distilled after fermentation is complete to increase their alcohol content. This way, the alcohol content can be raised up to a maximum of 95.6% (191 US proof), the concentration of the water/alcohol
azeotrope. When 100% ethanol (absolute alcohol) is required for scientific, commercial, or industrial purposes, other methods must be used. 100% ethanol is
hygroscopic, and if it's left open, it'll absorb water out of the air, reducing the concentration.
Origin of proof
The term originated in the 18th century, when payments to British sailors included rations of
rum. To ensure that it hadn't been watered down, the rum was “proved” by dousing gunpowder in it, then testing to see if it would ignite. If the gunpowder didn't burn, the rum contained too much water—and was considered to be “underproof.”
A “proven” sample of rum was defined to be 100 degrees proof. This was later found to occur at 57.15%
ethanol. This percentage is very close to a 4:7 ratio of alcohol to total amount of liquid. Seventy degrees proof is then equivalent to 40% ABV
[(4÷7)× .7 = 0.4]. And pure, 100% alcohol is 175 degrees proof [(4÷7)× 1.75 = 1.0].
This definition is no longer used in the United Kingdom; the ABV system must be used to state the alcohol content on bottles.
Further Information
Get more info on 'Proof Alcohol'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://proof__alcohol.totallyexplained.com">Proof (alcohol) Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
