CaCl2 in mash/sparge; CaSO4 in kettle

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brewzombie

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I have super soft tap water (essentially RO). I recently started using the Bru'n water spreadsheet and it told me that with my APA recipe, I had a pH of 5.4 without any mineral adjustments. But since I wanted the yeast health and flavour benefits of Ca and SO4, I added CaCl2 and CaSO4 in the kettle (instead of the mash/sparge) to get around 100 ppm Ca and 200 ppm SO4 (had I added these additions to the mash I would have got a low pH of 5.1). I felt good about my mineral adjustments, but recently learned on this forum that I should have at least 50 ppm Ca in the mash (for mash efficiency etc).

How do I get 50 ppm Ca in the mash and reasonable Ca and SO4 levels in the final beer for a hoppy APA?

These are my calculations using Bru’n water to assist. Please tell me if I’m off or if there’s a function in Bru’n water that does this for me. I also welcome any suggestions on the pros/cons of my final water profile for a hoppy APA.

New mash pH is predicted to be 5.2 (bit low, but better than 5.1)
Mash (3.2 gal): 0.7g/gal CaCl2 = 51.6 ppm Ca, 91.4 ppm Cl
Sparge: ignore (sparge water essentially RO, pH 7)
Boil (total pre-boil 7 gal): 0.3 g/gal CaCl2 + 1.3 g/gal CaSO4 = 102.7 ppm Ca, 191.8 ppm SO4, 40.4 ppm Cl

**Assuming that sparge rinses most of minerals in mash into kettle

Calcium contribution from mash = 51.6 ppm * 3.2 gal / 7 gal = 23.59 ppm
Thus, total calcium in kettle (pre-boil) = 23.59 ppm + 102.7 ppm = 126.3 ppm Ca

Chloride contribution from mash = 91.4 ppm * 3.2 gal / 7 gal = 41.78 ppm
Thus, total chlorine in kettle (pre-boil) = 41.78 ppm + 40.4 ppm = 82.2 ppm Cl

Final water profile for beer:
Ca: 126.3 ppm (adjusted)
SO4: 191.8 ppm (adjusted)
Cl: 82.2 ppm (adjusted)
Mg: 0.2 ppm (water report)
Na: 1.8 ppm (water report)
Bicarbonate: 3.5 ppm (water report)
SO4/Cl: 2.3 (I was aiming for 2.0, but this should be ok for a hoppy APA)

So, in order to get 50 ppm Ca in the mash, I've had to reduce my pH from 5.4 to 5.2. Is it worth it or am I better off with pH 5.4 without calcium in the mash?
 
If the mash pH is predicted to come out in an acceptable range without adding those Ca containing minerals to the mash and you want the extra sulfate and/or chloride, reserve those mineral additions from the mash and add them directly to the kettle. That will help you avoid a too low mash pH.
 
If the mash pH is predicted to come out in an acceptable range without adding those Ca containing minerals to the mash and you want the extra sulfate and/or chloride, reserve those mineral additions from the mash and add them directly to the kettle. That will help you avoid a too low mash pH.

Thanks for your comment. As I mentioned, that is what I initially did, but my question was that I wanted the recommended 50 ppm Ca in the mash to help with efficiency etc. The issue then was how to add 50 ppm Ca to the mash without messing up the pH and then hit my final target mineral concentrations in the kettle. The approach I gave above achieves this, but lowers the pH in the mash from 5.4 to 5.2. Maybe I can tweak the malt profile to get the pH back up or half the difference by aiming for 25 ppm Ca in the mash for a pH of 5.3. I suppose I could add base, but I don't want to do that without a pH meter and I don't plan on buying one for awhile still. I'm not sure pH strips will be accurate enough to discern 5.2 vs 5.4 even with the correction factor.
 
There is only a minor need for calcium in the mash and that is to precipitate oxalate from the wort so that it doesn't create beerstone at later points in the brewing process. I prefer to leave that in the mash tun, but it should be fine to precipitate it in the kettle too. Mashing with low calcium is OK, especially if it helps produce an appropriate mash pH. Using a base in the mash should be the last resort when there are other techniques that could suffice. Reserve those minerals for the kettle.
 
There is only a minor need for calcium in the mash and that is to precipitate oxalate from the wort so that it doesn't create beerstone at later points in the brewing process. I prefer to leave that in the mash tun, but it should be fine to precipitate it in the kettle too. Mashing with low calcium is OK, especially if it helps produce an appropriate mash pH. Using a base in the mash should be the last resort when there are other techniques that could suffice. Reserve those minerals for the kettle.

Thanks marbrungard. My water source has only 1.2 ppm Ca. Is this small amount ok for the mash given my pH is ok? I looked it up and it does seem that 50 ppm Ca is mostly recommended for lowering pH to the ideal range, which I don't have to worry about. As you said, it's also good for precipitating oxalate, but can be done in the kettle. I did see one other function, which may be a negative to not having it in the mash, which is that apparently the calcium ions protect the enzyme a-amylase from heat inhibition, but I'm not sure if this is worth it where my pH would be lowered a bit from the ideal 5.3-5.5 range.

I guess I'll stick with my adding minerals to the kettle, but once I try to use darker malts I may have to add some base to the mash once I get a pH meter.
 
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