High pH

[enrike]

Could anyone give me an advice what could cause a higher pH during fermentation? Cooled wort pH before pitching is about 5.25 during fermentation it only drops by 0.7 units respectively finished beer pH is 4.6 to 4.7 it's a bit to high for lager beer.


Thanks

[brewinhard]

the only factor I can think of is your original water that you brewed with. Did you give your beer adequate time to finish fermentation fully before checking the pH?

[ajdelange]

I have to think it is the yeast. They can pretty much set whatever pH they want within reaason. I've had lagers start with pH 5.25 or so fininsh at 4.65 and the same beer (different batch) from the same kettle pH finish at 4.5 with everything else being pretty much the same. A finished pH of 4.7 is, AFAIK, fine for a lager and while mine tend to finsih at pH 4.5 - 4.6 the ones that have finished higher have not been problem beers by any means.

[mabrungard]

Did you check the attenuation? The modest pH drop may be an indicator that the fermentation is not complete or insufficient.

[Afterlab]

Did you do a diacetyl rest at all?

[De-Geert]

When did you measure this? It could also be caused by autolysis, as the pH in the yeast cells is much higher. But in that case, it should have been lower before.