I know we've done this one before. Well, several times. But there's something about a good water analysis chart that you can't beat. A bit like an egg. No, not like an egg. You can beat that. What can't you beat? Your kids. A water analysis table is like the kids. You can't beat it.
This analysis is of a much later date than the preceding ones. I can't pin it down to a precise year, but the first edition of the book appeared in 1947. 1930's or 1940's would be my guess. Any way, here's the table with a little explanatory quote. I'd try to explain it myself but this chemistry stuff goes right over my head. If only I'd taken chemistry instead of history for A Level.
Table J.— Typical Water Analyses | ||||
Results in grains per gallon | ||||
Deep Well Waters | ||||
highest | lowest | Old | ||
Total solids (dried) | 160 | 86 | 32.4 | 22.4 |
Sodium—Na | 3.6 | 2.1 | 6.9 | 1.7 |
Calcium—Ca | 36 | 19 | 3.5 | 6.3 |
Magnesium—Mg | 5.7 | 4.3 | 1.3 | 0.3 |
Nitrate—NO3 | 3 | 2.2 | — | 0.2 |
Chloride—Cl | 4.7 | 2.5 | 4.2 | 1.3 |
Sulphate—S04 | 91 | 46 | 5.4 | 4.1 |
Carbonate—CO3 | 98 | 9.8 | 10.9 | 8.6 |
Calcium carbonate1 | 16.5 | 16.5 | 9.1 | 14.4 |
Calcium sulphate . | 99 | 41 | — | 1.9 |
Magnesium chloride | 2.1 | 0.7 | — | — |
Magnesium sulphate | 26 | 21 | — | 1.3 |
Magnesium carbonate1 | — | — | 4.7 | — |
Sodium chloride . | 5.3 | 3.3 | 6.9 | 2 |
Sodium nitrate | 4.2 | 2.9 | — | 0.3 |
Sodium carbonate | — | — | 3.7 | — |
Sodium sulphate . | — | — | 8 | 2.5 |
Permanent hardness (as CaCO3) | 97 | 49 | — | 2.6 |
Temporary hardness „ „ | 16.5 | 16.5 | 14.6 | 14.4 |
Total alkalinity | 16.5 | 16.5 | 18.1 | 14.4 |
Suitable for | Pale Ales. | Sweet, full stout not much used now). | Mild ales and stouts; with added gypsum for pale ales. | |
1 Actually present as bicarbonates. | ||||
The upper part of the table gives the quantities of the various ions as found by analysis. As all salts when in solution in water are dissociated into their ions, the salts as such are not present actually in solution. Furthermore, a little thought will show that it does not matter in what salt combinations these ions were originally added to the water. For example, considering the ions calcium, sodium, sulphate and chloride; these could be derived from appropriate amounts of calcium sulphate and sodium chloride on the one hand, or calcium chloride and sodium sulphate on the other, or from mixtures of all four salts in the requisite amounts. From the strictly theoretical standpoint it is therefore incorrect to express combinations of these ions as being present as salts as shown in the lower part of the table. However it is sometimes easier to visualize the type of water and to consider the appropriate treatment if the ions are presented as salt combinations, providing these have been made in a manner which shows up the characteristics of the water.
"Brewing Theory and Practice" by E.J. Jeffery, 1956, pages 101 - 102.
The Worthington and Allsopp wells had double the Sodium chloride (table salt) content, around 10 grains, of the 20th century analysis.The calcium carbonate levels are generally. Sodium sulphate, present in the Worthington wells, is completely absent in the table above from both the deep and shallow wells.
This demonstrates that there were considerable differences in water from different wells in the Burton area. There wasn't a single Burton water, but several variations of it, each with their own individual chemical signature.
Moving on to the London water, do you wonder why the Water Board supply has now appeared? Pollution id the simple answer. London brewers had to abandon their wells because of contamination and swapped to the town supply. Though, New River water in the older charts is also a type of municipal water supply. The Metropolitan Water Board and New River waters look quite similar, quite soft but containing a small amount of calcium sulphate and rather more calcium carbonate. Plus an odd little dash of salt.
Fascinating, eh? And I've not finished yet. In the next part we'll look at recommended water profiles for different types of beer.
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7 comments:
The paragraph you quote explains why there's no sodium sulphate recorded for the London Wells. There's sodium and sulphate (admittedly not much sulphate), so there is "sodium sulphate". The second half of the table is more like a recipe of how to recreate the ion mixture with commonly available salts. Though it doesn't bother to include the sulphate in any column I guess they thought it wasn't worth worrying about for the small quantity
For the more scientific or modern units of parts per million (ppm), multiply grains by 17.1.
You can see here, with a little calculation, why I often state that London has "funny" water. If you convert the calcium and carbonate to millivals or milliequivalents for London well water, you will see that the calcium content is 50mg/l = 2.5 mEqs. The carbonate content is 155mg/l = 5.17 mEqs.
During the boil, whether the water be boiled prior to use, or during the wort boil the 2.5 mEqs of calcium will bind with 2.5mEqs of carbonate and precipitate as chalk.
This means that there is zero calcium left and about 80mg/l of carbonate left (bound to sodium). The 80 mg/l of carbonate would be considered far too high by today's standards and the lack of calcium is considered bad for clarity and other processes. Mash pH would be too high for optimum efficiency.
It is rare for water to behave that way, Munich water is another that does.
In most other waters around Britain the calcium will pair up with the carbonate and both will precipitate to the solubility level of chalk (about 30mg/l CaCO3 remaining). Although still short on calcium, at least the carbonate is down to acceptable levels.
With London tap water the same applies. Most of the carbonate has gone and a little bit of calcium is left, bound to the sulphate. At least calcium can be boosted by adding gypsum, but of course in Gypseous areas this was not necessary.
It was probably this caused the switch to metropolitan water rather than well water, if that was indeed the case, not pollution. Indeed, in the cholera epidemics of the 1800s, it was the water companies' water that was contaminated, not usually the wells, except where the well wall was broken and a sewer or cess-pit ran adjacent to it. The reason was that the major water company drew its water supply from the thames downstream of the sewer outlets. And it was not unitl cholera came along in 1831 (A present from the Chinese via Russia apparently) that this became an issue because we had no immunity.
Barclay probably had access to New River water. It was pumped across the old Southwark Bridge by water wheel.
Jeff Renner said...
"For the more scientific or modern units of parts per million (ppm), multiply grains by 17.1."
Or 14.25 for grains per UK Gallon to ppm or milligrams per litre.
@ Graham - Thanks for the correction. I usually remember that we have different gallons, but had a brain cramp this time.
How I wish the US had gone through with the metrication that started in the 70's and was cut short in the 80's. Of course, this wouldn't make any difference here.
The thing that jumps out to me is the extremely high level of nitrates in Burton water. Converting grains to UK gallons (Thanks, Graham) that's something like 30-42 ppm. By comparison, actionable levels for U.S. drinking water are 10 ppm!
If Burton brewers were still drawing brewing liquor from wells with that level of contamination (given that nitrates in water are a sign of organic waste when they're not due to fertilizer runoff), I have to wonder how bad things had to be for the London brewers to stop using well water!
@ Graham. It's possible that deep London wells could have been contaminated by sewage. Limestone "karst" rock formations are notorious for unpredictable ground water flow, due to minor sinkholes and hidden cave formations. If a sinkhole hooks up with an underground river or stream, contaminated groundwater can travel for miles. I could imagine something similar happening in the chalk layers below London.
I agree that water company water and contaminated public wells were the main culprits behind the cholera epidemics of the 19th century, but it's possible that there might have been other sources that didn't get as much press. (For those who care, I recommend Steven Johnson's "The Ghost Map" as a highly readable retelling of the story of Dr. John Snow and the Broad Street pump. It will vividly remind you why beer was considered a health drink in pre-modern times!)
@ Ron, from what I've read I get the feeling that the mineral profile of London water, especially well water, was extremely variable. Does this jibe with your research?
Thomas Barnes, the analyses I've seen are pretty similar. At least the Thames Valley wells.
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