Struggling with water chemistry...

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

TomsBrew

New Member
Joined
Aug 23, 2016
Messages
10
Reaction score
2
Location
NULL
Hi guys, I have been doing a couple of brews recently but have been wimping out and using bottled water for them:whistle:. I would like to start understanding how to alter my own tap water better and been looking at Palmer’s how to brew guide.
I’m not going to give out my actual postcode but if anyone wants to check a local water report lets just use “ME7 3PD” as it’s close enough. The problem I am finding is that Southern Water does not seems to give the magnesium values for the water making it hard (or impossible???) to use Palmer's PH adjustment table.

kV9CGGv.png


To combat this issue I would uses the value given for CaCO3 (assuming this to be total hardness as both Ca and Mg) to back calculate the Mg value, my understanding from Palmer is:
Total hardness as CaCO3 is Ca as CaCO3 plus Mg as CaCO3.

The values given by Sothern are:
CaCO3 = 243mg/l (or PPM) this is not specified as total or anything.
Ca = 97.2mg/l

Palmer states Ca hardness as CaCO3 = Ca (PPM) /20*50
Using Ca =97.2mg/l or PPM
CaCO3 from calcium=97.2/20*50 =243mg/l

From the total harness equation I assume CaCO3 total = Ca/20*50 + mg/10*50

With my CaCO3 value from Ca alone equaling 243 this would mean zero mg…

So have I messed up or has southern water (assuming i have missed something here)…? :doh:

P.S. Sorry if this is really hard to follow… Also, sorry if my chemistry is completely flawed :confused:
 
It might be a silly comment, but inquire at your water company. The standardized report is there for legal purposes, but every water company has a full lab in the background.

Just tell them you're worried because you're (planning to) using the water for commercial brewing purposes and that it's crucial that the water does not have too little or too much magnesium. Insist to talk to someone from the lab.

They can give you the exact data of that day.

And I'm not sure if you guys use water towers, but the water is tested before it goes in the pipe. The pipes, watertower, etc can have a big influence on Ca, Mg, Fe, P and Cl readings. Mostly due to pipe wear, concrete corrosion and additional pH buffering. So if there's a water tower near your place, ask for the Mg levels from there.

I'm not sure what UK law says, but here they are required to present you that information.

pH calculators are nice, but the effect of your buffer also depends on what they used as a buffer. (Can't enlarge the image on my phone, so I'll just assume it's about that - pardon me if I'm wrong). Best is still to add a diluted acid/base to your brewing and just keep measuring.
 


Hi Rob, I have looked through that report and it does not give values for Mg or tbh anything i wold consider useful for brewing...


Pfeffer,
I have left them a message to get back to me but they never did, if there were no suggestions from this my next stage would be the process of nagging the data out of them.

Alternatively is there any simple tests (don't want anything complicated or costly) i can do at home to determine the water contents?

Thanks Guys :thumb:
 
I am in Epsom with super high calcium and alkalinity, but very low magnesium so alkalinity almost matches that contributed by calcium. I found the John Palmer stuff on water difficult to follow, despite being a biochemist, especially that chart you show. I test my own alkalinity (salifert kit...very easy to use) and calcium every few brews then combine that with the water company average values for soldier, chloride and sulphate then use a magnesium value I got when murphys tested my water. With my total hardness at 270-290 and calcium around 120, I typically add 6 grams gypsum plus a couple of grams Epsom salts for pale ales. Edit: forgot to mention adding 1.2 approx for memory crs/ams in the pre mash brew liquor to stop out the excess carbonates,
 
I'm not doing very well here, on an iPad in a caravan... 6gram gypsum for a 22.5ltr brew...and 1.2ml crs per litre off brewing liquor. ...and I'm only one my first bottle of cider.
 
Hi Rob, I have looked through that report and it does not give values for Mg or tbh anything i wold consider useful for brewing...


Pfeffer,
I have left them a message to get back to me but they never did, if there were no suggestions from this my next stage would be the process of nagging the data out of them.

Alternatively is there any simple tests (don't want anything complicated or costly) i can do at home to determine the water contents?

Thanks Guys :thumb:

I also got in contact with southern water regarding there water report dated 2015
They sead they would update it soon as they can
 
I am in Epsom with super high calcium and alkalinity, but very low magnesium so alkalinity almost matches that contributed by calcium. I found the John Palmer stuff on water difficult to follow, despite being a biochemist, especially that chart you show. I test my own alkalinity (salifert kit...very easy to use) and calcium every few brews then combine that with the water company average values for soldier, chloride and sulphate then use a magnesium value I got when murphys tested my water. With my total hardness at 270-290 and calcium around 120, I typically add 6 grams gypsum plus a couple of grams Epsom salts for pale ales. Edit: forgot to mention adding 1.2 approx for memory crs/ams in the pre mash brew liquor to stop out the excess carbonates,

I have to admit his water section is not as straightforward as the rest of the book, it doesn't help i cant get the values i seem to need though. I'm assuming magnesium is a harder mineral to test using a home kit?

Also i'm guessing it wouldn't be appropriate to just guess a random low value for Mg to calculate additives? I would quite like to move away from bottled water as its a pain and an additional cost.

Have you used PH stabilisers before? i have seen a coupled of people mention them.

Thanks :thumb:
 
I also got in contact with southern water regarding there water report dated 2015
They sead they would update it soon as they can

When did you contact them? i wouldn't hold your breath waiting for the to update it... my guess it will only get updated when they are next required to update it by ofwat...
 
You can get magnesium test kits but I decided it wasn't worth the money since magnesium isn't so important. I just add the couple of grams as a fail safe, probably not necessary but...... If the calcium content matches the alkalinity then the magnesium must be pretty low. Mine is around 5ppm based on murphys testing the water. You could put a dummy low value in..even if you do, the water software calculated addition of Epsom salt will be low so I wouldn't worry about it too much. I am much more co fortable using crs to strip out the carbonates based on an alkalinity test than using buffers to try to bring the ph into the zone. You will know if you've got the crs addition right when you do your first mash and see the mash efficiency...if the efficiency is good ( eg 70% plus) then you know you are on the right track.
After sorting my water treatment the biggest additional contribution to mash efficiency for me was moving to grinding my own malt.
 
I know there are aquarium tests to test magnesium, though I'm not sure on the accuracy of those. I think they are from salifert.
 
Magnesium kit is £8.99 so a bit more expensive than the alkalinity kit. Looks like it is designed for use in marine aquariums with salt water and high magnesium levels. On first quick reading it's only accurate in steps of 30ppm ( unless I've read wrong) then it's not accurate enough for what we want.
I'd assume that whatever that gap is between calcium and alkalinity , is most likely to be. Mainly magnesium and use that as a dummy guesstimate for the water software. You should be pretty close.., and magnesium isn't too critical.
 
Thanks for all the help guys, Southern water got back to me and hopefully are going to be able to send a more accurate water report to me next week!

I have been looking at the beginners guide to water treatment on this forum and maybe I have been over complicating things. If I carried out the below I’m sure it will be fine for my AG brewing?

Remove Chlorine: half a campden tablet per 5 gallon batch, before heating.

Alkalinity adjustment:
Test using a Salifert KH test kit.
Adjustment (probably always lower in my area): CRS @ 1ml/l to remove 190ppm - adjust as required.

Calcium adjustment:
Test: for now I will use the value in the water report? Or should I actually test for this using a Salifert Ca test kit?
Adjust to ~100ppm
For Hoppy beers: add gypsum to a max of 0.65g/l - 0.1g/l adds ~23ppm calcium
For Malty beers: calcium chloride to a max of 0.25g/l -0.1g adds ~27ppm
For balanced beer (e.g. English bitter): use a mix of gypsum and calcium chloride - is there a proper ratio I should go with or just 50/50?

I have seen some people use 5.2 ph stabiliser, is there any benefit of sing this if the above is taken care of?

And finally there seems to be loads of online water chemistry calculators, do you use these or do you calculate the additions yourself?
Thanks!
 
If you Measure the alkalinity then treat with crs then there is no need to add ph buffers. I personally like the Graham wheeler water spreadsheet which is on a rival forum but I also like the old water calculator on this forum.
 
On the calcium I decided to buy the calcium kit at the same time as the alkalinity kit... But it's up to you. On the additions, I'm stuck in a caravan in Dorset at the moment so would rather get back home to get my computer running and put a few numbers into it. If you post the more detailed report you get from your water company I'd be happy to run the figures though the calculators I use and see if it comes out with the same answers as you do.
 
Thanks Tartan, I think I will take you up on that offer if i manage to get the report :)

Btw what are your thoughts of outdated chemicals (gypsum, etc), i have some dated 2010 but i'm leaning towards just getting some new ones to be on the safe side.
 
Remove Chlorine: half a campden tablet per 5 gallon batch, before heating.

Alkalinity adjustment:
Test using a Salifert KH test kit.
Adjustment (probably always lower in my area): CRS @ 1ml/l to remove 190ppm - adjust as required.

Calcium adjustment:
Test: for now I will use the value in the water report

I'm in ME3 and this is pretty much exactly what I do, According to the figures I got from southern water (albeit a couple of years ago) Calcium is already at 97ppm, so for hoppy beers I now just use 35ml of CRS to treat 38L of water, plus just 2g Gypsum.
:cheers:
 
Thanks for all the help guys, Southern water got back to me and hopefully are going to be able to send a more accurate water report to me next week!

I have been looking at the beginners guide to water treatment on this forum and maybe I have been over complicating things. If I carried out the below I’m sure it will be fine for my AG brewing?

Remove Chlorine: half a campden tablet per 5 gallon batch, before heating.

Alkalinity adjustment:
Test using a Salifert KH test kit.
Adjustment (probably always lower in my area): CRS @ 1ml/l to remove 190ppm - adjust as required.

Calcium adjustment:
Test: for now I will use the value in the water report? Or should I actually test for this using a Salifert Ca test kit?
Adjust to ~100ppm
For Hoppy beers: add gypsum to a max of 0.65g/l - 0.1g/l adds ~23ppm calcium
For Malty beers: calcium chloride to a max of 0.25g/l -0.1g adds ~27ppm
For balanced beer (e.g. English bitter): use a mix of gypsum and calcium chloride - is there a proper ratio I should go with or just 50/50?

I have seen some people use 5.2 ph stabiliser, is there any benefit of sing this if the above is taken care of?

And finally there seems to be loads of online water chemistry calculators, do you use these or do you calculate the additions yourself?
Thanks!
You seem to have got it ok, don't overcomplicate it. For now you can just use the calcium value from the report and in the future you can get the Ca test kit if you desire. Test the alkalinity every brew then you will see if there is much of a fluctuation in the value. Also avoid the pH 5.2 stabiliser it's not needed and from what I've heard it isn't very reliable anyway.
 
Back
Top