hoegaarden and hydrometer chaos

[spearmint-wino]

You need to take an Original Gravity reading (one before fermentation) and one after to determine your ABV.

http://www.howtobrew.com/appendices/appendixA.html

Just to add to this that in that link Palmer states that all Hydrometers are calibrated to 15°c - this is not the case, in fact all the ones I have are calibrated to 20°c so would require a different correction table for measurements at temperatures other than 20°c. A 20°c correction table will be easy to find on the web

[David Edge]

15C hydrometers - this is most peculiar! I called the MD of Stevenson Reeves (hydrometers to the gentry) about this this week (a result of another discussion) and he said the only hydrometers calibrated for 15C are British Standard hydrometer calibrated for oil - which come in 15C and 20C variants. The standard for hydrometers for the UK has been 20C for years, and was 60F (15.6C) before that. UK beer hydrometers are calibrated for a specific surface tension as well, as specified by HM C&E.

However in a follow-on conversation with Geoff Cooper I discovered that a very long time ago there were indeed 15C hydrometers for pub cellar and winery work where the temperature is around 15C.

[Aleman]

One other thing to remember is that 60F is the NIST (US) standard temperature and therefore US Hydrometers are more than likely calibrated to this temperature (60F = 15.6C). My BeerTech Finishing hydrometer was sourced from the US and yes was calibrated at 15.6C I used it once and discovered that the glass where the lead weights were was very thin and had cracked - either in transit or when I gently floated it in the trial jar. SO I'm going to carry on looking for a properly designed Finishing hydrometer, with a sensible glass thickness at the bottom.

[delboy]

How they used to do it in the old days

As with all good things, successive governments would soon want to place a price on the enjoyment of the populace.
Local governments would set up a person to act as "ale conner", from Old English connere - "one who tests", in order to collect tax.

Ale was taxed on it’s strength, which was somewhat awkward since the measuring devices of the Customs & Excises were a long way off.
A far more accurate way to the judge the strength of an ale was to test the amount of sugar contained in the wort before fermentation, because it is the fermented sugars which produce the alcohol in the finished brew.
The ale conner would enter the establishment armed with tools of his trade - a pot to drink from and a pair of leather breeches.

Wort was poured onto any available flat surface, and then the ale conner would sit in it while he drank his ale. The strength of the wort was determined by the degree of stickiness affecting the conner’s leather breeches and the sugary surface, which was measured after a certain length of time had elapsed. The stickier the wort, the higher the predicted alcohol content.

[Graham]

15C hydrometers - this is most peculiar! I called the MD of Stevenson Reeves (hydrometers to the gentry) about this this week (a result of another discussion) and he said the only hydrometers calibrated for 15C are British Standard hydrometer calibrated for oil - which come in 15C and 20C variants. The standard for hydrometers for the UK has been 20C for years, and was 60F (15.6C) before that. UK beer hydrometers are calibrated for a specific surface tension as well, as specified by HM C&E.

However in a follow-on conversation with Geoff Cooper I discovered that a very long time ago there were indeed 15C hydrometers for pub cellar and winery work where the temperature is around 15C.

Hydrometers are generally calibrated at a temperature that suits the industry for which they are intended. For brewing they are (or, perhaps, used to be) calibrated at a typical fermentation temperature - deemed by C&E to be 60F (15.6 C). My Excise-approved range of professional hydrometers, purchased new about ten or twelve years ago, are calibrated at 15.6C. Chemists tended to use 20C calibration, brewers 15.6C.

In "Home Brewing, the Camra guide" there are two temperature correction tables, one for 15.6C and another for 20C, because when it was published even the cheapo home brewing hydrometers, purchased from home brew shops, were available in both flavours, and it was fairly arbitrary which sort anyone ended up with. I believe, for some strange reason, that the 20C ones were intended for Winemakers and the 15.6C ones for brewers, but the shop proprietors did not seem to be aware of that distinction, so it was pot luck if someone simply asked for a hydrometer.

It can even get worse. I embarrassingly complained when an expensive professional hydrometer seemed to be miles out of calibration. It turned out that, although it was calibrated for measurement at 20C, the scale was adjusted for water at 3.98C, the maximum density of water. I had ordered the wrong one. In those days the Gallenkamp catalogue (whatever happened to them?) had pages and pages (and pages) of different types of hydrometer for different industries, so it was an easy mistake to make - well that's my excuse anyway.

[David Edge]

For brewing they are (or, perhaps, used to be) calibrated at a typical fermentation temperature - deemed by C&E to be 60F (15.6 C).

Used to be indeed.

Stevenson Reeves home brewing range are all 20C: http://www.stevenson-reeves.co.uk/hydrometers/HBWB.htm

As for the professional ones, as long ago as 1998 the S-R catalogue shows brewers saccharometers being calibrated by default for 20C and 45mN/m surface tension. So Graham's are probably a little older than that.

There's an interesting article on hydrometers (1675-1905) in the latest Brewery History Society journal if you like that sort of thing!

[Graham]

For brewing they are (or, perhaps, used to be) calibrated at a typical fermentation temperature - deemed by C&E to be 60F (15.6 C).

Used to be indeed.

Stevenson Reeves home brewing range are all 20C: http://www.stevenson-reeves.co.uk/hydrometers/HBWB.htm

As for the professional ones, as long ago as 1998 the S-R catalogue shows brewers saccharometers being calibrated by default for 20C and 45mN/m surface tension. So Graham's are probably a little older than that.

I've looked into this a little further, as the subject has grabbed my interest.

In the end it depend upon what you call you call your measurement.

It seems by international convention (ISO 649, and ISO 650), that Specific Gravity is referenced to 60F (15.6/15.6), but Density and Relative Density is referenced to 20C (20/20). Density hydrometers are scaled in grams/litre, and the former in S.G.

This might explain why, in the good old days, that home winemaking hydrometers were 20C, and beer making 15.6C. Winemakers H's have a grams/litre sugar scale, so by convention should be 20C

If we are measuring S.G., then the convention should 15.6C.

Of course, in brewing things changed in the late 1990s to direct alcohol measurement by C&E rather than specific gravity, so I doubt if there is any need for an "official" saccharometer these days.

[David Edge]

If we are measuring S.G., then the convention should 15.6C.

Oh dear. Stevenson Reeves will have to stand in the corner and don the dunce's cap.

[Graham]

If we are measuring S.G., then the convention should 15.6C.

Oh dear. Stevenson Reeves will have to stand in the corner and don the dunce's cap.

Oh yes, dead right, for once you have said something sensible, I will elaborate when I am a little bit more sober. But it is a Friday, and I have just returned from the pub.

Stand back from reflected glory and think for yourself!

[David Edge]

In preparation for the elaboration, I'll put the question more formally.

Is the difference between what we 'should' do and what we do because:

IoB methods don't reflect ISO?

IoB does reflect ISO, but instrument manufacturers don't work to IoB?

IoB does reflect ISO, but brewers don't work to IoB?

I don't see why industry should adopt international standards unless there is a regulatory or strong economic case for it to do so, although to the extent that a particular sector participated in the preparation of a standard it could be viewed as an indication of the extent to which it reflects best practice. My work is with EN (Euronorm) standards rather than ISO however.

The home brewer would logically adopt the standard of the industry he interfaced with, so if you are an Internet person who says 'all-grain' then logically you would use ASBC standards whereas the 'full mash' brewer would reflect IoB. Not that I have the faintest idea what either espouses, but I'm not going to start lecturing my professional contacts about incorrect use of terminology!

[Graham]

It is statements like this:

15C hydrometers - this is most peculiar! I called the MD of Stevenson Reeves (hydrometers to the gentry) about this this week (a result of another discussion) and he said the only hydrometers calibrated for 15C are British Standard hydrometer calibrated for oil - which come in 15C and 20C variants. The standard for hydrometers for the UK has been 20C for years, and was 60F (15.6C) before that. UK beer hydrometers are calibrated for a specific surface tension as well, as specified by HM C&E.

...that make me wonder if you really were talking to the M.D. or whether they had palmed you off with the Janitor; the latter seemed more likely because I have shedloads of 15.6C hydrometers. If we are splitting hairs over 0.6 of a degree, then I am sorry, but I am sure that John Palmer meant to say 15.6C, or perhaps he said 15C for brevity. 0.6 of a degree is not going to make a busting lot of difference to the £2.99 jobbies that are sold by home brewing shops. Anyone worth his salt at the suppliers should have realised this also.

I was very careful to use the word convention, which is all that it is. Here is a link to the Stevenson range of general-purpose hydrometers. Observe that the whole damn range come in two types: Density measurement calibrated at D20/20C and S.G. calibrated at S60/60F or 15.6C. The other temperature 28.9C is again part of the ISO standard, but intended for hotter countries. Feel free to look around the site at the rest of their range, and you will find that the convention is generally adhered to.

So, yes, Stevenson does adhere to the convention, until it comes to the cheapo home brewing things. Given their price and the limited market, we can't really expect much from them anyway, and anyone would be far better advised to buy a couple of general-purpose laboratory types, which, if you wanted an S.G. scale on it rather than a density scale, would, by definition, be calibrated at 15.6C.

It is academic anyway. Hydrometers are made to the temperature that best suits the industry or application, which is why Stevenson's have a bespoke hydrometer service, and is why hydrometers are specified in terms like D20/20. That is the scale that is on it, the measurement temperature, and the reference temperature. As I mentioned before, I once accidentally ordered a D20/3.98C one.

For brewing, it is logical to have the hydrometer calibrated at pitching temperature, as, in the days when duty was determined by original gravity, the OG was taken just before pitching. The beer could be hanging around in the collection / dipping vessel for up to twelve hours waiting for the excise man to turn up. If he hadn't turned up within twelve hours of your declared collection time, you could assume that he wasn't going to turn up, and were free to pitch your yeast and continue with your brew. Twelve hours is plenty of time for the whole wort to be down to pitching temperature.

Although there is probably no such thing these days as an "Official Saccharometer", a commercial brewer uses a hydrometer for the same reasons that home brewers do; for quality control, it does surprise me that the so called professional brewers' saccharometers are now at 20C. I can see no logical reason for that. It may be something to do with IoB, but I doubt if they would move away from ISO / BS standards.

I am not really interested in what the IoB do anyway, I am really interested in what's practical from a home brewing perspective. And that is if a brewer wants a half-way decent hydrometer at a reasonable price (you won't get one at £2.99), then his or her option is to buy a half-way decent quality, off-the-shelf, hydrometer from a suitable supplier. By definition, for S.G. at least, it will be 15.6C

CRS next?

[David Edge]

Two points then:

I have just sat an exam in the home brewing sphere where the correct answer to the question was 20C; 15.6C and 15C. I had no intention of splitting hairs.

Re the Stevenson range of general purpose hydrometers, quite so. General purpose hydrometers are not surprisingly available for general purposes. The Saccharometers for Brewers and Distillers http://www.stevenson-reeves.co.uk/reeves/sacc.htm are calibrated for sg at 20C.

if a brewer wants a half-way decent hydrometer at a reasonable price (you won't get one at £2.99), then his or her option is to buy a half-way decent quality, off-the-shelf, hydrometer from a suitable supplier. By definition, for S.G. at least, it will be 15.6C

I'm not sure whether you are suggesting that these instruments are:
- not reasonably priced
- not of decent quality
or are from an unsuitable supplier.

[slim34]

the conversation has gone way beyond the abilities of my brain, but thanks to the advice about how to use a hydrometer, I am pleased to announce that I have successfully calculated the strength of a pedigree clone i created this last week to be 4.4 percent alcohol.

its obviously too late to use my hydrometer to test the strength of my hoegaarden clone but going by my own alcohol tolerance measure. I have tested it by drinking 4 pints and according to my then general fuzziness have concluded that it is indeed somewhere in the 5 percent alcohol mark.

[David Edge]

its obviously too late to use my hydrometer to test the strength of my hoegaarden clone

although if you know anyone with a refractometer as well you can estimate og and ABV using hydrometer and refractometer reading.

But the 'how long it takes to get to best mates mode' test is pretty accurate!

[PGSteamer]

I am pleased to announce that I have successfully calculated the strength of a pedigree clone i created this last week to be 4.4 percent alcohol.

Nice one