Test Mash Results

[el_loco]

I have been brewing exclusively light beers and my mash pH is too high. Calculating for temp. I'm getting 5.7 to 5.9. I'm working on fine tuning a House IPA and did one of two test mashes today. I used 2% sauermalz with a scaled down grain bill, mashed at around 150 and after 15 minutes checked pH, it was 5.67. To the sample that I checked I then added some CaSO4 and saw a minor drop to 5.61. Then I added a small amount of CaCl2 and saw a steep drop to 5.1!

I bumped the sauermalz percentage of the test mash up to 4% and checked pH again after 15 more minutes, was 5.62.

So according to my test mash for some reason (and could be user error but I was pretty careful with my numbers) even 4% sauermalz wasn't dropping my pH much. Perhaps leaving it longer would make a difference, but I was pleased to observe such a drop with the CaCl2. I may skip the sauermalz altogether and just figure the addition of CaCl2 that I'd need to get my pH right. Any advice from the chemists here on how to calculate?

 

[ajdelange]

Something isn't right here. Calcium is calcium. It does not drop pH more when it comes from the chloride than the sulfatae. A 'small amount' of CaCl2 does not drop mash pH by 0.5 pH. OTOH 4% sauermalz will drop pH by approximately 0.4. I suspect your meter may be unstable. Try the stability check (Step 11b) at
https://www.homebrewtalk.com/f128/ph-meter-calibration-302256/
and be sure your meter is calibrated and used per the rest of the suggestions there (though your owner's manual should be followed in case of conflict between it and the instructions in the Sticky.

 

[el_loco]

Will do, thanks.

 

[el_loco]

One note- The small amount of CaCl2 was stirred into the very small (maybe 4 tablespoons) mash sample. So the ratio would not necessarily reflect a mash addition, but it was just for my curiosity. I also re-checked my notes and I forgot to account for the temp correction on the second (4% sauermalz) test sample. It was 5.62 at 55 degrees, which according to the formula: Actual pH = Measured pH + [ 0.0167 x (Temp °F - 77) ] would mean the corrected pH is 5.25. If this is true it fits with the -0.1 per 1% acid malt as it means a 4 point drop in pH.