Mash pH at room temp or mash temp?

Ingredients
1

My notes show that I should have a mash pH between 5.1 and 5.5 at mash temp.

But, due to using a pH meter that is ATC (automatic temp correcting) that I need to subtract .3 from my readings to get to the mash temp readings. So a reading of 5.7 on my meter would be 5.4 at mash temp.

Is this correct?  ???

I don’t remember where I got those notes.

What should my mash pH reading (range) be on my ATC meter?

Thanks

2

This is a favorite topic of mine since it is quite confusing and there are many different opinions. This article has some detail: An Overview of pH - German brewing and more

In short:

  • don’t test at mash temp since this shortens the life of your pH meter probe
  • the room temp to mash temp pH shift is more like 0.2 than 0.35
  • Mash pH optima are generally reported as room temp pH values and by comparing them to room temp measurements you remove the ambiguity.
  • A correct room temp mash target range is 5.3 – 5.6 with the boundaries being quite fuzzy. I.e  5.2 and 5.7 should work too.
  • Don’t worry what the actual mash temp pH values are.

Kai

3

That is exactly what I was looking for.
I always take a few drops from the mash and test it and have been subtaracting .3 to get to the mash temp guidelines but wasn’t sure if that was correct.

Thanks again Kai !!