Questions about my water profile and adjusting pH

[eetu]

I got a report from my water supplier but I lack some measurements. I know the water is "soft" (between 50-100ppm) but didn't get numbers for calcium and magnesium. Total alkalinity is also missing. Here are the some numbers I got:

Sodium(Na), 13 ppm
Chloride(Cl), <8 ppm
Sulfate(SO4), 16 ppm
Water pH, 7.9
Water hardness, 50-100 ppm
Bicarbonate (HCO3), ??
Total alkalinity, ??

1. Is there a way to calculate close enough numbers without having to send my water to be analyzed?

2. Is TDS value useful in any way? I'm a bit confused with all these and having to learn them in a foreign language isn't certainly helping..

3. I put some numbers to EZ Water Calculator Spreadsheet and guesstimated some numbers for calcium, magnesium and alkalinity. Changing them between the given hardness level didn't affect the estimated mash pH by much at all. Does this seem correct?

4. With my helles recipe as an example, it suggested me to use gypsum roughly 10g per 20l (1/3oz per 5gal) to get mash pH below 5.6. What I have read, this should be pretty close to correct..?

5. None of the calculators I found take my original water pH into account. Do they assume the water used is neutral (pH 7), and I have to calculate a correction somewhow or is there just something I'm not quite understandin about this pH thing.

I'm not super interested in water chemistry and obviously my tap water is very very good and fresh tasting, so no need for anything drastic. pH is probably the biggest issue and I'm pretty sure my mash is too alkaline in most cases. I did order a pH meter to get actual data.

Am I on the right track and do you think it's safe/wise to try make adjustments with gypsum without knowing the exact numbers for calcium and magnesium?

 

[dmtaylor]

Not enough data to calculate alkalinity or mash pH effectively. You could experiment to figure out whether your mash pH falls into range without any salts, or how much to add. Do not rely on software.

Overall...... It appears to me that you most likely have relatively great water, and should ignore salt additions altogether, adding only a smidge of acid or 1/8 teaspoon baking soda to decrease or increase mash pH if necessary. Beyond that, just don't worry about it. It's not as significant a need as most homebrewers make it out to be. Seriously. If your beer tastes good, then it IS good, and you don't need to adjust a dang thing. I don't fuss over water anymore. I did for many years but I don't think it really mattered in the slightest. Recently I don't add salts anymore and the beer still is great.

Cheers.

 

[Silver_Is_Money]

You could make some guesses. It appears that your water hardness is between 50 and 100. And we know the following:

TH = (Ca++ * 2.5) + (Mg++ * 4.12)
(where TH = Total or General Hardness)

If we make the following first approximation assumptions:
1) TH = 75 (the average of 50 to 100)
2) Ca++ = 70%
3) Mg++ = 30%

We can solve as follows:

1) (75 * 0.7) = 2.5(Ca++)
Ca++ ~= 21 ppm

2) (75 * 0.3) = 4.12(Mg++)
MG++ ~= 5.5 ppm

A quick check:

TH = (21 * 2.5) + (5.5 * 4.12)
TH = 75.16 (or close to 75, so a good check)

So we can initially assume Ca++ ~= 21 ppm and Mg++ ~= 5.5 ppm

But now we can even go even further and guess as to the alkalinity by passing all of the known values through a program such as the "Water" page found on 'Mash Made Easy' and let the program do a cation/anion balance to speculate that your alkalinity is around ~75.5 ppm, and your bicarbonate is therefore ~92.1 ppm (since bicarb = ~ 61/50 * alkalinity)

Final initial guess summary:
Ca = 21 ppm
Mg = 5.5 ppm
Na = 13 ppm
Cl = 8 ppm
SO4 = 16 ppm
Alkalinity = 72.5 ppm
Bicarbonate = 92.1 ppm

And by this measure:

TDS ~= 21 + 5.5 + 13 + 8 + 16 + 92.1 (which presumes the other constituents to be very low in ppm values)
TDS ~= 156 + all other minor constituents

So your final check would be to see if a TDS meter comes in at a reading of a bit above 156 ppm TDS.

 

[Kent88]

You can get a range of what the calcium and magnesium are probably within, as Silver does above, but in order to really get it figured out, you will want to send off some of your water for testing.

Assuming that the above 21ppm is correct, you'll want more calcium. According to the brewing elements series Water book, brewers want between 50 and 150 ppm of calcium in their water. Calcium has a variety of functions in brewing, I think it is important for enzyme reactions in the mash, and I know it is an important yeast nutrient.

According to that same book, magnesium should just be kept under 40ppm, as enough can usually be extracted from grain to provide the yeast with what it needs.

So by assuming that Silver's estimation is correct, you just need to bump up the calcium a bit. If you're making malty beers you will want to do this by adding some CaCl, if you are making hoppy beers you'll want to add gypsum CaSO4, or perhaps some combination of the two.

 

[ajdelange]

I got a report from my water supplier but I lack some measurements. I know the water is "soft" (between 50-100ppm) but didn't get numbers for calcium and magnesium. Total alkalinity is also missing. Here are the some numbers I got:

Sodium(Na), 13 ppm
Chloride(Cl), <8 ppm
Sulfate(SO4), 16 ppm
Water pH, 7.9
Water hardness, 50-100 ppm
Bicarbonate (HCO3), ??
Total alkalinity, ??

1. Is there a way to calculate close enough numbers without having to send my water to be analyzed?

No. Not really. But we can guess at some ranges. With hardness between 1 and 2 mEq/L (assuming ppm to mean ppm as CaCO3), sodium at +.23 mEq/L, chloride at -.22 and sulfate at -.33 for balance we'd have +.23 + 1<-->2 = .22 + .33 + alk. Thus alk = 1.23<-->2.23 - 0.56 = 0.68 to 1.68 mEq/L (34 to 84 ppm as CaCO3)

2. Is TDS value useful in any way? I'm a bit confused with all these and having to learn them in a foreign language isn't certainly helping..

No, not really.

3. I put some numbers to EZ Water Calculator Spreadsheet and guesstimated some numbers for calcium, magnesium and alkalinity. Changing them between the given hardness level didn't affect the estimated mash pH by much at all. Does this seem correct?

The popular calculators over estimate the effect of calcium and magnesium. Even so they show a relative small influence on pH. Alkalinity is quite different. It can have quite a profound effect on mash pH but that depends on the malts mashed, the thickness of the mash and so on). For a typical base malt with a typical grist to water ratio you might expect to see pH shift about 0.04 units for each added mEq/L alkalinity (50 ppm).

4. With my helles recipe as an example, it suggested me to use gypsum roughly 10g per 20l (1/3oz per 5gal) to get mash pH below 5.6. What I have read, this should be pretty close to correct..?

You really can't rely on the guidance those calculators give. Adding calcium is not a good way to control mash pH. Make sure there is 20 - 50 ppm and set mash pH with acid or sauermalz. You might want to add half to 1 gram calcium chloride to your water and use 2 - 3% sauermalz. Your alkalinity isn't that bad.

5. None of the calculators I found take my original water pH into account. Do they assume the water used is neutral (pH 7), and I have to calculate a correction somewhow or is there just something I'm not quite understanding about this pH thing.

No, you are understanding this. The first generation spreadsheet authors are the ones that don't understand that to calculate mash pH related things accurately them must know the source water pH. However, given that alkalinity is known one can assume that the proton deficit for the water is approximately 88% of the alkalinity (in mEq/L) as actual proton deficits, which do depend on pH, are close to this. That is what the spreadsheets seem to do.

I'm not super interested in water chemistry...

Pity! It's a fascinating subject. Just ask my wife!

and obviously my tap water is very very good and fresh tasting, so no need for anything drastic. pH is probably the biggest issue and I'm pretty sure my mash is too alkaline in most cases. I did order a pH meter to get actual data.

Your water is pretty much OK from what we can tell about it at this point. We usually think of 1 mEq/L alkalinity (50 ppm) as the level below which we do not need to worry about it. You are in that region. A little sauermalz should fix that. The pH meter is the way to go. You might want to consider aquarium test kits for alkalinity and hardness.

Am I on the right track and do you think it's safe/wise to try make adjustments with gypsum without knowing the exact numbers for calcium and magnesium?

You should be OK with half a gram to a gram of CaCl2 and 2 - 3% sauermalz until the pH meter comes.

 

[eetu]

Wow, thank you all! Amazing. I'll see how my mash pH is without any adjustments first and go on from there. I'm still not quite understanding all of it and probably never will. But when I brew, I want to know what I'm doing and why I'm doing it, or not do it at all. Otherwise it would be quite impossible to keep learning.

My beers taste great and when they don't I can figure out why. I'm not trying to fix anything, this water thing is more like the last steps I'm taking in my process.

This hobby is amazing in so many levels. Learning stuff has never been more fun, not to mention the delicious juice that is the end result of all this!