Second batch using Bru’n Water today. Both 100% Weyermann Pilsner and Jever (boiled) profile. Bru’n Water predicts pH 5.40, both mashes just under 5.3. What can I do to dial this in in the future?
What are you using for acids in the mash?
Lactic 88%
I’m assuming that you’re using distilled water so that isn’t a factor. Varying water quality from RO or tap water could have that effect.
It’s RO at about 5ppm TDS. Maybe that’s it. I’m also still running the spreadsheet on Android with no macros, if that matters. I suppose next time I could just adjust the acid calculation to predict pH ~5.5 and see if that corrects it?
That is nice low TDS, so the bicarbonate content should be very low. Almost distilled level.
Macros aren’t involved with pH calculation. Macros are only used on the Supporter’s version to save and recall data files.
My first thought on anything like this has to do with confidence in measurement.
Are you sure your measurement was correct? Quality instrument, representative sample, calibration, Positive there is no mistake in your volumes, grains, lovibond, spreadsheet #'s, etc.
Secondarily, is this a consistent event - brew 3 beers with similar water/grain/additions - do you always come in at the same range? If so, I just adjust accordingly.
Personally, I find my dark beers coming in lower than projected pH… So, I have just learned to compensate and now get consistent numbers where I want them.
I think the measurements are pretty tight, and the instrument reasonably accurate – at least sufficiently so that the “error” of pH 0.1+ must be something else. Something in the “black box” of my system, ingredients, etc. But with identical results two brews in a row, I think I’ll try just compensating as I said: calculate acid for 0.1 higher than target. I’m not too worried, as I still consider pH +/- 0.1 of target close enough.
Have you checked your malt analysis on the Weyermann pilsner malt? They provide a lot of info on there including lovibond and pH just to name a couple.
Didn’t check the analysis because I haven’t been able to get the QR to scan on the last couple of bags. But my experience has always been that Weyermann Pils runs high if anything on the pH.
My last couple Barke sacks have been at 5.9 pH.
Yeah, that’s why I’m surprised I’m coming in BELOW the predicted pH, Weyermann is usually high end of what I would expect the spreadsheet to assume.
I don’t own a PH meter and don’t plan on getting one. I use Bru’n Water and am happy with the results so far.
This appears to have been merely a matter of when the sample was pulled. Waited an extra 15 minutes today and pH was within 0.01 of prediction.
I’ve long reported: wort pH varies during the mashing period. The other thing that is curious (in my experience), is that the pH tends to drift toward a room-temp pH of about 5.4 during the mash. If the pH is initially higher than 5.4, it tends to fall and if initially lower, it tends to rise. I can’t explain it, but it has proven typical in my experience.
Brewed a APA yeasterday. Hit the predicted value of 5.30 on the nose. Later, it came in at 5.38 before mashout.
This is my theory: Mash WANTS to become wort and ultimately beer.
“…and wants us to be happy.” 
Belated but thought I’d report: this past weekend I waited 15 min to pull sample again. Bru’n Water predicted pH 5.39. Measured ph: 5.39!
I’ve always seemed to chase mash pH, and always hit low vs. prediction. This past weekend I switch to distilled from RO, but the result was the same. Prediction was 5.52, I measured 5.33. Sample taken 30 min into mash.
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