Water Chemistry!

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I still cannot grasp the difference between carbonates and bicarbonates.
I'll give a go and try and help. I might get something wrong, so don't hold it against me.

Bicarbonates raise (or buffer) the pH and prevent you reaching mash target. So you want to reduce bicarbonates until the web tool suggests your mash pH will be OK.

Calcium is good for your mash. It helps flocculation etc. You want at least 50ppm, not too far past 100ppm.

One easy way to reduce bicarbonates is to boil the water, as it combines with calcium and drops out as calcium carbonate, aka the stuff that furs your kettle. This is Wheelers recommended method. Now you might have noticed a negative side effect of this approach, i.e. you've now lost some calcium, and you didn't want that. So Wheelers blanket approach is to a) boil, then b) throw some calcium back in. The idea is, it'll be better than doing nothing.

Boiling is not the only way to counter the bicarbonates. I have a high 220ppm and address by adding Phosphoric Acid (also found in Coca Cola by the way, in case adding acid sounds weird). Of course you really need to know your water well before you go down this path. I used Alk Salifert test.

To know my Calc levels, I used Ca Salifert test. When adding calcium (if necessary) you can choose whether to add Calcium Sulphate (Gypsum), or Calcium Chloride, or a mix of both. The first increases your Sulphate levels and raises hop prominence. The second increases your Chloride levels and raises malt prominence. While adding to hit your target calcium level, you would adjust the gypsum/calcium chloride amounts, depending on your starting water levels, to achieve a required Sulphate/Chloride ratio for your specific planned beer.
 
I have very soft water, and I am very happy with my pale beers, to which I simply add gypsum, and a little Epsom salts, and I'm also happy with my dark beers, to which I add nothing to the water. Gypsum definitely improves the pale beers. Science may say other wise, but my lack of scientific understanding means I stick with what works for me, I see no need to do any more. I've tried adding calcium chloride to dark beers, as instructed by water calculators, but I prefer the results without it, taste wise.
 
...we have soft water and adding calcium sulphate lowers the PH even further so we need to add calcium carbonate to raise it to act as a buffer.
Sounds like you have very different water to me; very low bicarbonates. Opposite approach than that I outlined above would be required in such a case. Add chalk (calcium carbonate; kettle fur) to bring the carbonate levels up to help buffer the pH, or you might undershoot.

You would only really need to add Calcium sulphate if you needed more Calcium (e.g. often after boiling).
 
Sounds like you have very different water to me; very low bicarbonates. Opposite approach than that I outlined above would be required in such a case. Add chalk (calcium carbonate; kettle fur) to bring the carbonate levels up to help buffer the pH, or you might undershoot.

You would only really need to add Calcium sulphate if you needed more Calcium (e.g. often after boiling).

Its quite interesting, the brewers friend calculator advocates treating the entire volume of water, not just the mash. I cannot say if its the same for other calculators. Here is my water report and here are the additions I would need to make to get a balanced profile according to the brewers friend calculator.

Water supply zone Carron Valley B

Calcium mgCa/l - 9.89
Magnesium mgMg/l - 1.10
Hardness mg/l as CaCo3 - 29.19 (HCO3- 35.61)

Sulphate mgSO4/l - 13.91
Sodium mgNa/l - 4.63
Chloride mgCl/l - 8.14

Volume 32 litres

Chalk CaCO3 - 2g add 0.53 tsp
Baking Soda NaHCO3 - 1g add 0.23 tsp
Gypsum CaSO4 - 2g add 0.50 tsp
Calcium Chloride CaCl2 - 3.2g add 0.94 tsp
Epsom Salt MgSO4 - 1g add 0.22 tsp
 
We're I to venture into the chemical mine field. I take it I could just fill the HLT treat water accordingly and that would be the lot done for mash and sparge?
 
what would I need to do to my hard south west London (Wimbledon/Kingston way) to make it good for bitters? The couple I've done haven't been as good as my other brews and I'm wondering if water treatment is worth playing with? I'm sure myqul commented on this at some point?
 
It is generally the level of Alkalinity expressed as HCO3 that need to be adjusted to match the level of your beer style. Once you know the level you can reduce this by addition of acid (CRS)
Chloride and sulphate levels usually found in your water report need to be controlled for hop utilisation,flavour and sweetness. These can make a difference to your beer.
Calcium is also important but can be present in excess and usually is as caclium chloride and calcium sulphate (or Gypsum) is used to control these minerals.
Treat your sparge water for alkalinity for the whole brew and add minerals, calcium and chloride in the mash, just mix them with the grains and when soluble will do their job.
This is a simple approach to water chemistry and levels need to be calculated based on your water and style of beer being made. Preserving the ratios of chloride/sulphate for a particular beer style can be equally as important as the actual amounts.
 
Bungle
It sounds a lot more complicated than it is in practice. Once you know the levels of alkalinity, calcium and sulphate its is simply a case of adding a calculated amount each brew. If you always make pale ales then this would be fixed and will be different for stouts/porters.
It's not the end of the world if you don't but should improve your beer. it certainly improved mine.
 
what would I need to do to my hard south west London (Wimbledon/Kingston way) to make it good for bitters? The couple I've done haven't been as good as my other brews and I'm wondering if water treatment is worth playing with? I'm sure myqul commented on this at some point?

Yes I did. I treat my water for bitters (but don't need to for dark beers). First of all get a salifert alkalinity test kit and test the bicarbonate level of your water (mines 188ppm) then using some brupaks CRS and a online water calculator adjust the water till its below 50ppw (for bitters if iirc).
For the other salts, Thames water will have your local water report online from last year to give you some ball park figures you can put in the calc. Or you could send a sample to Murphys and Son's of your water (according to SteveJ they'll do it for free in the hopes you'll buy all the chemicals/salts from them) for a full water report
 
Its quite interesting, the brewers friend calculator advocates treating the entire volume of water, not just the mash.
As others have mentioned, no problem keeping it simple and treating all your water in one go.

As I understand, the most critical factor in all of this is to hit the correct mash pH. But there are advantages in treating post-mash water also, but for different reasons.

Reason 1 would be reducing the possibility of drawing out tannins during the sparge. But to draw out tannins, your water also has to be over a certain temp (can't remember the exact degrees off the top of my head). So if you have close control over your temp, it removes this as a reason to treat your post-mash water.

Reason 2 is fermentation aid. I believe it aids yeast health and flocculation. But here this becomes a lot less critical than the mash pH impact.

So you can see how treating only the mash water is a valid option.
 
Think we're I to do it I'd just treat the lot.

yes because most Mash volume is around 12-15 litres for say 5 Kgs of grain. It would make measuring very small quantities difficult it one was measuring only for the Mash. Plus the Mash while certainly the most critical is not the end of the matter. I am sure Graham Wheeler advocates adding 5mg of Calcium Sulphate to the boil as a matter of routine! (Brew your own British Real Ale page 55) :-o
 
So im still waiting for my report back but! the brewery that i was at said they use the same water supply as me, so he new roughly without a report how to help me with my IPAs and the results were use DWB use 4>5g in the mash 2>2.5 in the sparge

AMS to combat tannins can not remember the amounts as his ales were so good my note states 57ml per BBL in the Mash, Sparge 164l BBL

I will have to go back this week and not sample any brews to make sense
 
After reading this more confused than ever. I added 3.5g of gypsum last brew to roughly 15l and it raised the PPM from 10 to 220. Seems like a large increase to me, my tap water is about that. Anyway its an interesting subject and i shall persevere. Cheers
 
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