Baffled by water calculations

[brian_beer]

Hi all,

So I've spent a loooong time reading and re-reading most of the posts here with regards to water treatment but I still am missing something fundamental in how to calculate additions.

In short, I'm planning on a Fullers style beer so trying to use a 'London' water profile. According to Beersmith this is:
London, England
Calcium(Ca): 52.0 ppm
Magnesium(Mg): 16.0 ppm
Sodium(Na): 99.0 ppm
Sulfate(SO4): 77.0 ppm
Bicarbonate(HCO3): 156.0 ppm
PH: 8.0 PH


Now, according to my water supplier, I have the following profile (yes, I know it may be inaccurate but my problem here is with the calculations, not with the outcome):
Calcium: 97 mg/l
Magnesium: 4.6 mg/l
Sodium: 38.35 mg/l
Sulphate: 65.513 mg/l

I have no reading for Bicarbonate, but the hardness is recorded as: 292mg/l CaCO3

Now, if I follow the calculations then I should reduce the alkalinity by 242-262mg (so I use -256 from the table on brupaks) so I should use 1.4 ml/litre of CRS.

That part makes sense, so I move onto the next section - Calcium...which is where I fall down.

Original alkalinity in ppm x 0.4 = Calcium in ppm
292 x 0.4 = 116.8. This is close enough to my reading to be believable, but the instructions then tell me how to increase calcium as "A typical Bitter requires a calcium content of 180-220 p.p.m." - however the water profile as above shows that I need 52 ppm so I would need to reduce the calcium content.

So on paper I seem to have twice as much calcium as I would need, but most things I read suggest that calcium content should be higher, not lower. I guess this means I have 2 questions -

1. Is the figure above right for calcium content in London water? It seems to be corroborated in BrewersLair calculcator, but doesn't match up with the general rules on calcium levels (e.g. Aleman:Aim to adjust it to at least 50mg/l or better still closer to 150mg/l. )
2. What is the right way to reduce the calcium content? Even if the above is wrong, Graham's calculator suggests 50mg/l for Lagers so let's pretend that's what I was brewing. I'm struggling to find details on this, I did read that boiling the water would reduce the calcium content, but not by how much and I wouldn't know what else would be lost/gained by doing so.

I'm sure others must have had this question, but the only calculations I can find seem to be for going in the opposite direction. Probably just have my head screwed on backwards, so I guess someone will find it easy to set me straight.

Thanks in advance

[WallyBrew]

You do not say where you are but the figures from your water supplier are of the order that would be expected for London mains water.

I think you should take a step back here recheck Alemans post in the Brewniversity. Here you will find all about alkalinity.

Your hardness of 292 is NOT ALKALINITY. Hardness is merely a measure of the soap destroying properties of water and is generally caused by calcium and magnesium though strontium would also be included in this. For brewing purposes hardness is generally a good thing but it has to be one of the two types of hardness.

The two types of hardness are permanent and temporary. Temporary hardness is that which is removed by boiling and for most waters this equates to most of the alkalinity - this is the bit YOU NEED TO DETERMINE (london mains is about 190 -220 as calcium carbonate) and is also the bit that you want to remove. If you choose to boil the water to remove it then all but about 20mg/L as calcium carbonate will get precipitated and you will have reduced your calcium content. If you choose to neutralise it by use of the ubiquitous CRS then all of the calcium and magnesium that is theoretically combined with carbonate and is regarded as temporary hardness will be converted to permanent hardness and you will not have reduced your calcium content.

In conclusion, if you determine the alkalinity of your water and reduce it using CRS (or another acid) then your calcium will still be about 97mg/L. This is in the range that is given by Brewing Science and Practice by Briggs etal and of course in the range given by Aleman.

[brian_beer]

Hi Wally,

Thanks for the response. Might be making me more confused though....

(For clarification, the quote attributed to Aleman was actually a bumped post originally from Chris-x1 "http://www.jimsbeerkit.com/forum/viewto ... 71#p388099". Just wanted to clear that up in case anyone else spotted the mistake)

This post begins:
---------------------
"Before you do anything, you want to know the total alkalinity of your water expressed as CaCO3 Don't be supprised if this isn't on your water report.

CaCO3 is shorthand for Calcium Carbonate. To standardise alkalinity figures and calculations, brewers refer to alkalinity as an equivilent amount of CaCO3 present in 1L of water. It can be expressed in other ways but we want to know it expressed in terms of CaCO3 or calcium carbonate.

Expressing it as an equivilent amount of CaCO3 or in other words expressing it in terms of CaCO3 means interpreting alkalinity as if it were calcium carbonate that was entirely responsible for the total alkalinity of the water.

This standardises the way we deal with alkalinity and makes some simple calculations even easier."
---------------------

This is the detail that I had just been reading and used as the basis for assuming that the hardness given by the water company was logically equivalent to alkalinity. I have re-read the above several times and still believe that this is what it says. However, this is most likely down to my lack of knowledge in the area and I expect that I'll spot my mistake in time.

Regardless, it's really the lowering of calcium that I am struggling to find any info on.

In your final note, you confirm that I will still have 97mg/l calcium in the water - according to the London profile, I need less than that (52ppm). That's really where I'm confused as I rarely see mention of decreasing the calcium in the water.

I think I've read enough to convince myself that I might as well just use the tap water for now and not complicate my life by trying to change it, but it would be nice to understand what it is that I don't understand.

Thanks again.

[Eric]

Minefield, isn't it?
I think London's water may contain 52 ppm calcium in permanent solution, with other being temporary as calcium bicarbonate (or carbonate after boiling). However that water will likely be treated by the brewer to increase its calcium content to near the figure you were expecting.
Alkalinity and hardness can be measured in the same units and while the two are different, without testing a sample of water it is hard to know if the figure you are given is the one you need.
Your logic seems fine by my understanding.

[Naich]

The best way to find out the alkalinity of your water is to measure it. Get a KH Salifert test kit off Ebay and follow the instructions here - http://www.jimsbeerkit.co.uk/home_brew_ ... linity.htm

The alkalinity of your water can change depending on where the water company sources it from, so the figure from your water company might not be accurate anyway.

[brian_beer]

Eric - Thanks for the response. That would definitely make more sense given the lack of info, however it seems a little surprising that they would have treated their water back at the start (how would they even know what to do before this site was invented )....if they could, I'm sure that there wouldn't have been so many breweries in Burton.

I suppose London well water might have not needed treatment (even if it wasn't as good as Burton): "Fuller’s used to have an artesian well, but now draws water from the mains".

I'll go find some other non-issue to concern myself with now

[gregorach]

In your final note, you confirm that I will still have 97mg/l calcium in the water - according to the London profile, I need less than that (52ppm). That's really where I'm confused as I rarely see mention of decreasing the calcium in the water.

That's not really a large difference, and not worth worrying about. Too little calcium can cause issues, but too much isn't a worry unless it's really a lot too much.

[Eric]

Eric - Thanks for the response. That would definitely make more sense given the lack of info, however it seems a little surprising that they would have treated their water back at the start (how would they even know what to do before this site was invented )....if they could, I'm sure that there wouldn't have been so many breweries in Burton.

I suppose London well water might have not needed treatment (even if it wasn't as good as Burton): "Fuller’s used to have an artesian well, but now draws water from the mains".

I'll go find some other non-issue to concern myself with now

No, you are right about the lack of water treatment in early times. However, it was recognised that water played an important part as can be read in "The London and Country Brewer" of 1736 and available from http://www.gutenberg.org/cache/epub/8900/pg8900.html

As I understand matters, when canals allowed beer to be transported from Burton to London, it was bought by the elite who would not normally drink the darker local beer. It has been said that this action was just inverted snobbery as London beer of that period was apparently good stuff, being made with more roasted malts that countered bicarbonates in the water.

As you suggest, the given water profiles are probably modern day supplies while in early days, breweries would be placed near convenient water sources with vastly differing water profiles. Not until into the second half of the nineteenth century was single sourced water available across highly populated areas, after the cause of earlier cholera epidemics had been identified. Even then, brewers with suitable water would probably continue to use their own supplies, faecal pollution wasn't necessarily such a problem to them, unless the new supply was better. Now we have Chief Chemists instead of Head Brewers and can make any style anywhere yet still have arguments such as between so called Northern and Southern made beers.

Anyway, Dunc's cut to the quick, it's better to have a bit too much than too little, also applies to many other things.
Cheers,
Eric.