Originally Posted by tally350z
When I received the PH meter I calibrated using both the 4.01 and 7.01 buffers. I washed the ph meter with Distilled water before and after each reading, and I made sure the sample was a close to room temp as I could get it...
You need to calibrate your pH meter at every brew day, no ifs and or buts about it. Put you two buffers into shot glasses or whatever, and just leave them out so you can re-check a couple more times during the brew day. A couple times I've gotten a measurement (Hanna 98128.)that was higher than expected, and I rechecked and found the calibration was off, after just an hour or so. Like was noted above, that's the art of it.