Talk:Alcohol proof

Arithmetic
The use of the numbers 4,7, 100 and 175 in the first (History) section seemed pretty confusing. I have tried to clarify it. 87.194.252.37 (talk) 06:46, 11 May 2009 (UTC) MJB 11-5-09


 * The numbers 4, 7, and 100 are explained in this section. The number 175 pops up, and seems arbitrary, because this is an arbitrary definition. Any other definition of "100 proof" would simply result in some other arbitrary-seeming number.Wahrmund (talk) 19:38, 11 May 2009 (UTC)


 * Think the explanation is still a little unclear, trying to come up with something a bit easier to understand AJGordonWright (talk) 16:09, 22 March 2012 (UTC)

95, 96?
Is that 95% alcohol limit true. Over here in Finland the pharmacists bottles all claim 96%. Maybe the folks accross the pond just rounded that 190 proof down to the nearest ten? -- Cimon Avaro on a pogostick 05:15, Oct 31, 2003 (UTC)

Also it might (or might not) be worth explaining that two liters of 100° proof alcohol contain what would, if separated, be one liter of pure ethanol and a little over a liter of water and other things, since the liquids shrink a little when combined.

The azeotrope of water/ethanol is close to 95-96%. I'm guessing that it is just a preference thing.
 * That's QI. Not sure whether it fits the article though. Stanstaple (talk) 18:32, 11 August 2009 (UTC)

At standard pressure, 95.63% is as pure as ethanol can be distilled. Pressure-swing fractioning is required for higher purities. Since beverages are nearly always watered down, the 4.37% of water left is ignored. Industrial spirit has the remaining water 4.37% removed chemically with calcium hydride.220.240.250.5 (talk) 03:36, 6 January 2015 (UTC)

The great divide
It might also be worth mentioning that UK Proof is different from US Proof; Pure alcohol is 175% Proof in the UK. CS Miller 17:09, Apr 8, 2005 (UTC)

Reason for revert
I reverted this article back to pre IP addressee's modifications. This article is writen in english which uses the word "proof" as an indicator of alcoholic content. In addition, Robert Boyle invented the hydrometer in the 17th century. Proofing of alcohol came soon after. The article was correct prior to our drive by's input.

Alcoholic Proof Redux
As far as I'm aware ethanol is extremely hydrophilic. So, as soon as it is exposed to air, it will pull water molecules from the air and dillute the ethanol to roughly 95% alcohol. I believe you can get the percentage up to 98% by doping the ethanol with methanol, or other substances that are generally unsafe to drink. The only way to have 100% ethanol would be to put your ethanol in a vacuum, where there would be no other molecules to dillute your alcohol. Of course, as soon as you opened your 100% ethanol vacuum packed bottle, it'd almost immediately drop to 95% as the air hit it. Even if you drank it from the vacuum pack with a straw, the ethanol would grab moisture as it touched your throat, and drop to roughly 95% before it hit your stomach. So, for those of you looking for a shot of 100% ethanol, you're out of luck. (I'm about 95% sure that this information is correct. However, I'd recommend someone check with a chemist before posting this outside of the discussion page.)
 * Not quite. It would take quite a while to pull 5% volume water out of the air. Very pure alcohol is produced by a number of processes like salt drying, lime reaction, and three-part azeotrope distillation. However, "pure alcohol" is not sold to the ordinary public in most places. Rmhermen 00:22, 27 February 2006 (UTC)

Proof outside the Western world
It might be worth mentioning (or not) that the world outside North America and Europe doesn't use "proof" and won't have a clue what it means. It's therefore probably sensible not to give the proof of a beverage without the equivalent ABV, especially in Wiki articles describing various spirits. --Charlene.vickers 04:39, 2 February 2006 (UTC)

Someone should have pointed out by now, and it should be mentioned in the main article, that the word "proof", in the context of alcohol concentrations, is an archaic use of "proof" such that to prove something meant to test it. The concentration of alcohol was tested by checking whether it would burn. There are other puzzling but commonplace uses of proof with this meaning, such as "the exception proves the rule," which means that, an exceptional circumstance tests a rule. --Janice Vian, Ph.D. (talk) 17:45, 2 May 2015 (UTC)


 * I think millions of people in Europe don't have a clue what "proof" means, hence the number of people who wrongly talk of "% proof", or even misread "proof" or "&deg; proof" as "% proof". This is all the more reason to always give ABV.  To both of you: If you find an article that gives proof strength but doesn't give the equivalent ABV, please fix it! — Smjg (talk) 21:38, 16 June 2015 (UTC)

Production passage necessARy?
Unless I'm missing something, I don't really see why a description of the alcohol production process is necessaRy here, in an aRticle about a unit of meaSurement. Maybe the passage here could be integrATed with saY fermentation.


 * If you mean the "Alcohol content in beverage production" section, then I agree, it has no relevance whatsoever. It doesn't even mention proof, it's all about ABV. AJGordonWright (talk) 16:13, 22 March 2012 (UTC)

This section is in the article to provide background information. It relates the ABV concept to the common types of alcoholic beverages. Readers who want to convert the ABV number to the proof number may consult History section of this article. Wahrmund (talk) 20:24, 23 March 2012 (UTC)

Firewater?
That comment about the etymology of firewater is a load of shit. Someone with balls should remove it. LOL I wrote 'firewire' instead of 'firewater'!

"If a 150-proof beverage is mixed half-and-half (by volume) with water, the product is 75 proof"
I have added Fact because when you mix 3 part of pure alcohol with 1 part of pure water, you get less than 4 parts of liquid, so diluting that mixture 1+1 with water will not give you the same result as mixing 1 part water with 1 part pure alcohol. Man with two legs 09:29, 16 June 2007 (UTC)
 * I have now altered it to fit what I think is likely to be accurate and adequately readable:
 * ...the product is close to 75 proof (not exactly because of a small volume change when alcohol is mixed with water)
 * -unless there is a fiddle in the way the thing is measured that makes this wrong. Accurate facts, anyone? Man with two legs 21:00, 25 June 2007 (UTC)

Percent, present?
ABV, the unit that is commonly used at percent ... shouldn't that be "at present"? Maikel 15:20, 27 September 2007 (UTC)

Why gunpowder?
''To ensure that the brandy being used as payment has not been watered down or was of good quality, it was proved by dousing gunpowder in the rationed brandy, and testing to see if it would ignite. If it didn't ignite, the solution had too much water in it and the proof was considered low or "underproof".'' Great story. But why go to all this length and not simply light the brandy you're trying to test? I know from experience that if you want to flambée anything and therefore need alcohol that burns, you have to get the 54% ABV stuff. And according to the article, 54% ABV roughly equates 100° proof. So I suspect that "proof" simply means "alcoholic drink that burns". Maikel 15:59, 27 September 2007 (UTC)
 * You can burn ordinary 40% booze if you warm it first, so burning is not a practical test. Man with two legs 21:05, 27 September 2007 (UTC)

Alcoholic proof
The point is: wherever the term is used, in America or elsewhere, the definition is always "twice the ABV." No one thinks of it in terms of the 18th century British usage. So how is that misleading? Also, the term is not "modern" in the U.S. Wahrmund (talk) 20:32, 4 November 2008 (UTC)
 * Ah, you thought it was ancient history! The British definition was used in every supermarket not that long ago and is familiar to British people over the age of about 35 who remember that most gin and whisky were 70 degrees proof (corresponding to American 80 proof).  It also will be relevant to books and newspaper articles that are not all that old.  For example, the Dick Francis thriller Proof is still available new.  I do not remember exactly what happened when ABV took over, but I vaguely remember a period when both measures were printed on bottles. It is unlikely that the American definition has ever been used in Britain. Man with two legs (talk) 11:13, 7 November 2008 (UTC)

anhydrous ethanol?
Is there a difference between 200 proof and lab grade "anhydrous" ethanol? 4.255.55.13 (talk) 18:59, 18 January 2009 (UTC)
 * Not according to http://www.pharmco-prod.com/pages/ep1.pdf, which says 200 Proof Ethanol is often referred to as “Dehydrated”, “Anhydrous”, or “Absolute Ethanol”. --Vaughan Pratt (talk) 06:33, 12 July 2010 (UTC)

why 2:1?
The article explains where the British relation 7:4 comes from, but does not mention why and when the American 2:1 relation was introduced. --194.24.138.3 (talk) 18:34, 1 February 2010 (UTC)

I second this question :) --Inez Korczyński (talk) 04:30, 26 May 2013 (UTC)


 * The definition was made by government fiat. I don't know if the regulators had any particular reason for it in mind, other than (possibly) simplicity. Wahrmund (talk) 17:01, 26 May 2013 (UTC)

Barrel proof
Barrel proof redirects here, but there is no mention of what it means. On http://en.wikipedia.org/wiki/Buffalo_Trace_Distillery there is a chart with a column named "style notes" where some have the note Barrel proof.

This sentence does not make sense
The article claims "Thus, the definition amounted to declaring that (4÷7) × 175 = 100 degrees proof spirit." which means nothing, as (4÷7) × 175 equals 100 regardless of the definition of alcoholic proof. A more accurate claim would be "Thus, the definition amounted to declaring that if a fraction x of a spirit was ethanol, then that spirit is x × 175 degrees proof." Can anyone else find a better way to put it? smithers888 (talk) 02:37, 7 May 2010(UTC)


 * That is all very well, but the text needs to point out the reason for the choice of 175 as the multiplier. They could reasonably have decided (perhaps because of measuring error or the use of a different kind of gunpowder) that a ratio of 5:7 would be declared to be 100 degrees proof spirit. Then the multiplier would be 140 instead of 175. So pure alcohol would be 140 degrees proof instead of 175 degrees, which would considerably compress the scale.


 * Or they could have decided that the top of the scale would be 200 degrees proof. Then the formula would be (1÷2) × 200 = 100 degrees proof spirit, which is the standard that was introduced in America. In the event, they used the "rum+gunpowder+match" standard which resulted in the 175 multiplier.  See the "Arithmetic" section above. Wahrmund (talk) 22:12, 7 May 2010 (UTC)

Merge with Alcohol by volume?
The only difference between ABV, US proof, and UK proof is the number of parts by volume of the whole thing the alcoholic portion is compared with. These parts are respectively 100, 200, and 175. (So 100% ABV is 200 proof US and 175 degrees proof UK.) Except for that, this article and Alcohol by volume are about exactly the same thing. The fact that ABV historically had older units which are still used in places does not seem like a good reason for having two whole articles. Redirecting Alcoholic proof to Alcohol by volume (after suitably merging the contents) would avoid creating the impression that there is a more substantive distinction between the two concepts. For example the second sentence of this article says "The UK now uses the ABV standard instead of alcoholic proof," but this is misleading because the US now requires the ABV standard on all labels too, and no longer requires the proof though it permits it. Thoughts? --Vaughan Pratt (talk) 21:28, 10 July 2010 (UTC)

Confusing quote from The Joy of Mixology
"Using the OIML scale or the Gay-Lussac scale is essentially the same as measuring alcohol by volume except that the figures are expressed in degrees, not percentages." This states that OIML scale uses degrees, but I only see references to percentages in the referenced OIML recommendation #22. Alcohol by volume page does refer to degrees Gay-Lussac though. I realize that this is supposed to be a direct quote (can't verify) and there's not much to do in terms of editing it, but it is somewhat misleading and perhaps should be omitted. Aurimas (talk) 00:53, 3 November 2013 (UTC)

Is the part about rum and the Royal Navy correct?
I once read a rather authoritative book on spirits (don't remember the name or author, sorry) that told the story of measuring the proof of rum for the Royal Navy but for a different purpose. According to this article, it was done to show the men that they weren't receiving watered down rum. But I thought the real reason was much more practical: to prove the rum on board ship was not flammable, a very important consideration in the age of wooden ships, especially if they have to go into battle. In the account I read, the ships were NOT allowed to carry rum at or above 100 proof because it was a potential fire hazard. This account much more sense than what is in the article. Does anybody else know any better?209.179.40.208 (talk) 23:37, 26 March 2014 (UTC)


 * I've seen that too, but can't remember where. It would make a good addition to the article if we can find a source. Kendall-K1 (talk) 23:08, 16 June 2015 (UTC)

No citation connecting proof to sailors.
The gunpowder process and the fact that sailors drank rum is attested in the sources, but no connection between the two is included. Furthermore, one of the citations specifically states that proofing was for tax purposes. I find the connection with sailor's rations dubious. Dalzay (talk) 05:51, 12 March 2016 (UTC)
 * I'm pretty sure the real reason is given in the previous talk page section "Is the part about rum and the Royal Navy correct?" It would be good to dig up some sources. Kendall-K1 (talk) 14:36, 12 March 2016 (UTC)
 * I took a stab at fixing this. I took out the Ministry of Rum source because although it talks about sailors being paid in rum, it doesn't connect that practice to "proof". Whoever wrote that section had a vivid imagination. Kendall-K1 (talk) 16:51, 12 March 2016 (UTC)

Canada
"However, the old UK proof standard is still used casually;" I'm Canadian and I've never heard someone referring to "proof". Not even once. The standard format on labels is e.g. 40% alc./vol. and this is what people know and use. The Canadian Food Inspection Agency labelling requirements are listed here: http://www.inspection.gc.ca/food/labelling/food-labelling-for-industry/alcohol/eng/1392909001375/1392909133296?chap=6

Gentleman wiki (talk) 01:30, 10 October 2016 (UTC)


 * The cited source is dated 1972, and says Canada uses the UK system. It does not say the UK system is still in use (and can't, since it's dated 1972). I have modified the text. See what you think. Kendall-K1 (talk) 02:01, 10 October 2016 (UTC)

But it's somewhat misleading: Officially, Canada follows U.S. usage in labeling .... On the contrary Canada does not follow US usage. In the US labels prominently display the proof content. In Canada they do not. I find that there is little value to add that in 1972 some people may have used proof. ABV was still the official measurement in the 1970s. Gentleman wiki (talk) 22:27, 27 December 2016 (UTC)
 * The US allows but does not require proof on the label. I believe Canada is the same. But I see no value in the comparison and have removed it.
 * I do see value in noting that Canada still used UK proof, not ABV, in 1972. This seems well sourced and I would leave it in. Do you have another source that says Canada was using ABV on their labels in 1972? Kendall-K1 (talk) 23:09, 27 December 2016 (UTC)

Maths mistake?
Why does the article say proof (in England) is "about 1.821 times" the ABV, and then later say 57.14% (or 57.15%) which is 1.75x (not 1.821x)?

78.149.230.39 (talk) 20:42, 18 September 2019 (UTC)

The persistence of the burning gunpowder origin
As with most online sources, this article indicates that the ignition of gunpowder dowsed in the liquor was the original proofing test, and even lists a seemingly reliable source for such a claim... But I'm having a hard time swallowing this story. Why, in the 16th century, would tax collectors and distillers be buying and wasting gunpowder (which assumedly was expensive) on a test for which you could obtain almost the exact same results by simply lighting the alcohol itself? Why would anyone even associate alcohol with gunpowder? It seems to me that the story of testing alcohol on naval ships to make sure it was "navy strength," and therefore would not ruin their gunpowder if it spilled, (which seems to be a very real practice) is getting confused with the basic concept of testing liquor for alcohol content by doing the obvious thing of burning it.

Based on this hunch, I checked out the PDF listed as a reference 1. It's a rather informal response to a question about the origin of "proof" written by a chemistry professor, William B. Jensen, from the University of Cincinnati. In it, Prof. Jensen claims the origin is gunpowder burning and provides as citation pages 561–575 of the book The World of Measurements: Masterpieces, Mysteries and Muddles of Metrology by H. A. Klein. However, upon doing a word search through this whole book, I can find no use of the word gunpowder at all. Reading the pages cited by Prof. Jensen the book only has this to say of the origin of proofing:
 * "The concept of a standard or normative "proof" strength was operative in Britain from the early days of the burn-or-no-burn tests. It paralleled the normative concepts of applied to brewing..." –this is found on page 564

I see no reason to assume this is referring to gunpowder... why would it be, especially without explicitly mentioning gunpowder anywhere in the book?

Based on all of this, I propose we: remove the Prof. Jensen reference and (at the very least) list the idea of gunpowder burning alongside the more basic concept of just burning the alcohol, the latter of which should list the H.A. Klein book as a citation. Are there any strong feelings about this? Cheers, Skoulikomirmigotripa (talk) 19:57, 12 May 2020 (UTC)