Working out water chemistry

[Charles1968]

The knowledge on here never ceases to amaze. Thanks for all the info.

Can someone tell me if I understand (in an extremely basic way) alkalinity in brewing ...

With the correct level of alkalinity (and starting ph of water presumably) our malt bills should acidify the liquor to an ideal pH (5.2-5.5). If the water has a high alkalinity, something in the water (please fill the gaps) acts as a buffer stopping the grains doing what they should do and bringing the mash pH down. Therefore if we find that the water has high alkalinity, we can add something (again please fill in) to compensate for the acid neutralising entities.

First gap: bicarbonate

Second gap: lots of options. Gypsum, calcium chloride, acids (various), darker malts, acidulated malt.

It's not just the mash you need to think about. When you sparge you rinse out all the chemicals that hold the mash pH down and so pH rises. As a result, the hot water starts to extract nasty stuff from the grain. So you need to treat your sparge water or at least take care not to overdo the sparging.

[Eric]

For pale grists, the mash typically needs "less than zero" bicarbonate content for the mash pH to drop into the ideal range.

By itself, that statement is very misleading. It applies only if the water from your tap close to distilled with understanding of Kolbach's measurements on wort at "knock out" using such water and a belief that those results are applicable to your water.

In nature, totally pure water is very rare as it would dissolve most other materials it contacted. This picture was taken close to my home, and looking at the cliffs you should see below the top 20 to 30 feet of glacial till (boulder clay) the magnesium limestone left by the Zechstein Sea, with top smoothed and levelled by those passing glaciers from the northern icecap.


Last week a sample of water taken directly from a spring in that rock close to where that picture shows, which has been the source of the local water supply for well over 150 years, had alkalinity that measured 340ppm and hardness of >500ppm CaCO3. To neutralise all (bi)carbonate it is standard practice to add acid until pH is 4.5 and I can assure you, as you will have already observed, any mash pH with that particular liquor with zero or slightly positive alkalinity would be well below 5.

Water with low ion content having little or no alkalinity can therefore have a pH higher than water with more alkalinity as exampled above.

[jez666]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

[Charles1968]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

You're doing it the right way.

[Dave S]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

But be aware that CRS adds both sulphate and chloride to the water, so you might want to use separate sulphic/hydrochloric acids depending on your water analysis.

[jez666]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

You're doing it the right way.

Thanks for the reply Charles, that's reassuring

[jez666]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

But be aware that CRS adds both sulphate and chloride to the water, so you might want to use separate sulphic/hydrochloric acids depending on your water analysis.

Thanks Dave could you explain how I could work out the quantities of each acid to use, I have got a pdf of my water report but can't attach it. The link is below

http://www.stwater.co.uk/households/you ... de=st5+0jb

Thanks

Jez

[Dave S]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

But be aware that CRS adds both sulphate and chloride to the water, so you might want to use separate sulphic/hydrochloric acids depending on your water analysis.

Thanks Dave could you explain how I could work out the quantities of each acid to use, I have got a pdf of my water report but can't attach it. The link is below

http://www.stwater.co.uk/households/you ... de=st5+0jb

Thanks

Jez

You'd be as well to download Bru'n Water, though I don't think the free version supports CRS. However, the supporters version is by donation so you can pay what you think it's worth to you. I think I paid about £10. I can tell you it's well worth it. What you do then is input your water analysis which might require you to jiggle the numbers a bit if you got averages from your WA until the ion match. you then choose the water profile you want and most importantly check what your alkalinity is. If for example you are brewing a pale ale you want the alkalinity to be down around 30 ppm, but no higher than 50. You get it down by adding the appropriate acid. Which one you use will depend on the Sulphate:Chloride ratio you want. Without scaring you further I suggest you get the spreadsheet and read the the instructions. You may find it daunting at first like I and others did. But after you've had a good play around it becomes really quite easy to use.

EDIT: Looking at your water report, it's pretty useless as is. It doesn't contain the very elements you require. They are: Calcium, Magnesium, Sulphate, Chloride and sodium. These are the values you need to enter into the spreadsheet.

[Eric]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

3.6 meq/l (milliequivalents per litre), but yes, as said you've got it.
Indeed the water report isn't ideal, but on the plus side the measurement you made fits with what they've provided and using CRS to reduce alkalinity should have improved your beers. A much better starting point would be a proper analysis of your tap water.
Reducing alkalinity in that water with CRS for pale beers, as DaveS advises, will produce roughly equal sulphates and chlorides. Pale beers more usually have a sulphate biased liquor to produce a drier beer and emphasise the hops. It would appear your water has sufficient calcium but could take more. If you added 10g of gypsum to a 23l brew, say half to each the mash and boil, the sulphate:chloride ratio should produce a more hoppy result.

[Charles1968]

Hi,

I'm also trying to get to grips with this subject, after using the salifert kit I get a reading of 3.6 mg/l alkalinity. I have then been multiplying by 50 to get 180 mg/l CaC03 and using this figure to treat my water with CRS. Can someone tell me if this is correct or should I have been doing it a different way?

Many thanks for any advice.

But be aware that CRS adds both sulphate and chloride to the water, so you might want to use separate sulphic/hydrochloric acids depending on your water analysis.

Thanks Dave could you explain how I could work out the quantities of each acid to use, I have got a pdf of my water report but can't attach it. The link is below

http://www.stwater.co.uk/households/you ... de=st5+0jb

Thanks

Jez

Wow, almost nothing of use in that water report. I'd carry as you are doing with CRS. No point bothering with the bru'nwater spreadsheet or gypsum additions unless you know all the figures for the key ions, such as calcium, magnesium, sulphate and chloride. If you want to get a full analysis, it's £22 - look up Murphys water analysis.

[jez666]

Thank you all for your input. Dave I've downloaded the bru'water omg it looks a bit daunting but I will have a play when I've got a day or 2 . Eric my next brew is going to be a hoppy ipa so I will do as you suggest with the gypsum and see what difference it makes. Charles I'm going to get my water tested at Murphy's thanks for the suggestion.

When I get my results back I'll post them here.

Thanks again

Jez

[markm1878]

My KH/Alk kit arrived. Having read the instructions, I believe after adding 4ml of water and 4 drops of the KH-ind, I then draw 1ml of one of the other bottles and let it in a little at a time until the colour changes.

There are 2 other bottles though, the smaller one is labelled Standard Check Solution 6.7 dKH = 2.40 meq/L and the larger is just labelled KH. Which do I use, and what is the purpose of the other?

[keith1664]

The check solution is just that, you use it instead of your water as a test, the colour change then occurs at 2.4 meq/l.

[AnthonyUK]

I then draw 1ml of one of the other bottles

This is where you use your own water to test.
As mentioned, the check solution is just to ensure the test solutions are OK and not affected due to shelf life etc.

[markm1878]

Ok great, so its just to be used the first time and then discarded?