I've been using Brun for a while now and for most of my IPAs and dark beers, I get pretty close, probably with in .1 or .2 for mash pH reading compared to predicted.
But on some beers, usually with out any large crystal or roast additions, the pH prediction is much further off.
Here is my latest example.
Using 100% RO water, 10.4 Gallons for a 6 gallon batch, no sparge
GW 2 row (B) 3.0# 2L
Pale Malt (B) 2.0# 3L
Pilsner (B) 4.0# 2L
White Wheat (B) 2.0# 2.4L
Caramunich (C) 3.0# 51L
I'm adding in:
Gypsum (CaSO4) 5.7g
Calcium Chloride (CaCl2) 2.5g
Pickling Lime (Ca(OH)2) 1.6g
Brun' estimates 5.5 mash pH (room temp).
I doughed in at 153 and hit strike temp of 148F and stir in the mineral additions. I wait about 8 minutes, do a bit of recirculation to mix things some more and then I pull a sample into a chilled cup.
I calibrate my pH meters (HMDPH200 and no-brand from AHS) ( prior to reading (7 and 4 solution)
On the above mash, I measured 5.12 at about 90F. I added 1.0g of Baking Soda and after another 5 minutes, this was up to 5.21 at 100F, and then another 1.6g of Baking Soda, and brought me up to 5.42 at 97F.
I'm wondering if this is the typical for the 'ball park' estimate of spreadsheet calculations or if I'm missing something in my process or input.
btw, if I add the 2.6g of Baking soda back to Brun, it calculates a pH of 5.7, so still a good .3 pH off from what I measure.
Thanks for your time, and the spreadsheet!