Rethinking pH sample "time"

[balrog]

I take a sample from the mash at 30 minutes. I take it in a large 60ml syringe, for no evaporation effect.

But I wait until it has cooled to measure the pH, sometimes 2-3hr later.

I was blithely going along this route, checking pH w/ different calculators and adjusting next time I made the same recipe based on what I got previously. But my most recent Pils was WAY off and I'm wondering if "time to measurement" might be having an effect.

Recipe #210
Nothing added to the water at all (1/3 potassium Campden for chlorites in 27.5qt full vol mash, ground dusty w corona mill)

 

[jdauria]

Guessing that the strength of the acidulated malt was not as strong as the three water calculators predicted. I know the paid version of Bru'n Water defaults to acid malt strength of 1, but you can adjust it up or down depending on what your actual pH is so that it's more accurate predicts future batches.

I take my readings at 20 mins, most literature I have read suggest taking mash pH within 15-20 mins. Then I keep shot glasses in the freezer and will pour sample into first shot glass to chill it down, then in the 2nd to chill down until I get to room temp. This allows me to take a reading within 2 minutes of pulling the sample. Even though it's already too late for the current mash, it still allows me to just thrown in another mL of lactic if I am way off for the heck of it.

 

[Silver_Is_Money]

'MME' has broadly (as well as easily) adjustable acidity for acid malt. But one must measure to a respectable level of confidence before jumping the gun and changing the default. One occurrence of deviation is grossly insufficient data upon which to jump into changes. Many other factors may be at play, and one shouldn't arbitrarily make presumptions as to pointing the finger definitively at acid malt.

There will be lot to lot and brand to brand (season to season, region to region, etc...) variations in acidity for acidulated, just as for any malt.

@balrog, is this your first time using this brand/lot of acid malt?

 

[balrog]

'MME' has broadly (as well as easily) adjustable acidity for acid malt. But one must measure to a respectable level of confidence before jumping the gun and changing the default. One occurrence of deviation is grossly insufficient data upon which to jump into changes. Many other factors may be at play, and one shouldn't arbitrarily make presumptions as to pointing the finger definitively at acid malt.

There will be lot to lot and brand to brand (season to season, region to region, etc...) variations in acidity for acidulated, just as for any malt.

@balrog, is this your first time using this brand/lot of acid malt?

Not to my knowledge; trusting RiteBrew to sell Bestmaltz Acidulated as Bestamaltz Acidulated. Only other recent batches using it were the dry irish stouts I made. I do note how they ran a little higher measured than predicted, but MME was not that far off from measured while with the pils, all calcs predicted much lower than measured.