BruN water question pH for Robust Porter

[rwing7486]

Hey Guys, I am brewing a robust porter this weekend and I have adjusted my water profile to be similar to London's water. My question comes from the estimated pH value. Below are the values calculated from Brun Water. My question is my estimated room temperature mash pH is 5.6 which is OK - but is this the actual pH value my mash will be at when mashing at 152 degrees F? or will it be higher or lower? should i had some latic acid to lower the pH or are these values acceptable?


Net Water Alkalinity(mEq/L) = 1.7
Total Mash Acidity (mEq/L) = 2.6
Net Mash Acidity(mEq/L) = 1.0
Estimated Room Temperature Mash pH = 5.6

 

[mabrungard]

The room temperature pH is the ONLY value you need to be concerned with. The room temperature pH values are correlated to resulting outcomes in beers. While there are no defined or precise pH targets, falling within reasonable range of the target range will produce better outcomes. The brewer's art and craft is the decider as to whether they prefer the pH to be higher or lower to produce the end result they prefer.

Yes, the mash pH is actually around 0.3 units lower at mashing temperature than room temperature. But that fact is meaningless. When you standardize on a room temperature measurement and assess the resulting beer, altering the mash and wort pH based on the result is all that matters.

 

[ajdelange]

The actual pH of the mash at mash temperature depends on the temperature and several other factors. 0.0055 pH/°C is what I have observed and is the number I usually use. Thus if 5.6 is what you measure at room temperature (20 °C) and you strike at 50 °C (122 °F protein/beta glucan rest) would be about 5.6 - 30*0.0055 = 5.43. At sacharrification temp of 150 °F (65.6°C) actual pH would be about 5.35. Thus when pH at mash temp. is mentioned you have to specify what you mash at and no one ever does that so specification of mash temp. really does not make much sense. That doesn't stop people from doing it though. Of course the room temperature scheme doesn't really let you know what the actual pH of the mash is unless your mash exactly follows the 0.0055 pH/° rule. There is a similar situation in aviation. Above 18,000 feed pilots set altimeters to 29.92 in/Hg and thus their altimeters don't read the actual altitude unless the barometric pressure on that particular day at their particular location is actually 29.92. Keeps the planes vertically separated though.