Barleywine test mash

[jmf143]

I preformed a test mash for a barleywine I am brewing tomorrow and measured the pH at various times in order to compare my readings with the predicted pH readings from Mash Chemistry and Brewing Water Calculator v1.5 (pH 5.48 predicted) and EZWater 3.0 (pH 5.44 predicted)

I scaled the grist, brewing salts and lactic acid to the appropriate amounts for mashing in 1 qt of water. Before doughing in I did a 2 point calibration of my Hannah 991001 pH meter. I added my salts and lactic acid to 1 quart of water and heated it to 170 degrees. 2 samples were drawn from the mash, sample 1 immediately after doughing in and sample 2 15 minutes after doughing in. Both samples were put into glass vials and immediately placed in a cold water bath. I sprayed distilled water on the probe and blotted dry with a paper towel between readings.

Here at the readings I recorded. All times in minutes after doughing in:

Sample Time pH Temp
1 7.5 mins 5.05 80.0
1 11 mins 5.19 77.3
1 17 mins 5.34 74.6
2 20 mins 5.36 81.8
1 23 mins 5.31 73.9
2 25 mins 5.35 78.0

I am targeting a mash pH of 5.40 in my barleywine. Based on these readings, I am going to reduce the amount of lactic acid by one-half on brew day. I will draw a sample 15 minutes into the mash and measure the pH to determine if any additional acid is needed.

 

[ajdelange]

I'd say you are easily at least 'close enough for government work' (maybe we need to rethink use of that term given Obamacare) so don't reduce the lactic acid too drastically. You might want to run a stability check on your meter: https://www.homebrewtalk.com/f128/ph-meter-calibration-302256/