Measuring pH the day after

[PJM]

I tired to measure the pH of my mash and the wort in the kettle on Saturday for the first time and found that I needed to soak the probe of the meter for 2 to 4 hours before the first use. I ended up measuring the pH of the samples the following day. I covered the samples with a paper towel and left them out on the counter over night. Are the numbers still good or is it likely that the pH would have changed under these conditions? They came in at 5.51 for mash and 5.28 in the kettle.

Thanks.

 

[revansCAAD8]

I would say no, not good. Your mash ph will change even over the duration of regular mashing time. Most check their mash ph like 10-15min in. Also your wort that you left out overnight can actually start to 'sour', dropping the PH.

 

[ajdelange]

Assuming that no bacteria or wild yeast got in there and started off a fermentation you are probably OK. Mash pH drifts over time but that is largely as the substances in the mash liquid gain access to the stuff held up in the grain matrix. Even in the mash tun most of the drift occurs in the first 20 minutes or so. Better, of course, to have your meter calibrated, checked and ready to go before water meets grain.

 

[PJM]

Thanks guys. So, for future reference, is there some standard time like 15, 20 or 25 mins, at which the mash should be checked? I think I took my sample about 10 minutes after I got everything good and stirred up.