Ph reading when blinking stops or final number?

[tomaso]

Quick question: My ph meter stops blinking and according to instructions that's the ph value but then it drops more until it stops.

Today's brew: stopped blinking at 5,7 but then dropped further to 5,45 until it stopped moving.

Which one is the correct reading?

Thank you!

 

[ajdelange]

That depends on how stable your meter is. The way to find out is to do a calibration and then leave the electrode in the buffer. If it reads close to the correct pH for the buffer temperature over a long period of time then the meter is stable. See the sticky.

Assuming the meter is stable then the answer to your question is that both the readings are correct. The reactions that establish mash pH are slow. Typically it takes a mash half an hour to come close to its equilibrium pH though it should be most of the way there after fifteen. In estimating mash pH we obtain the parameters for the malts based on their test mash pH readings after half an hour.

If your meter is not stable then the answer to your question is that none of your readings are correct.