Low temp mash- high Ph equals?

Doing a Kolsch and i have a mash Ph of 5.8. Mash temp was 150 for 75 minutes. Which has a greater effect on the beer? Temperature/time, or Ph?

they all have effect but pH may be the biggest effect.  That ph is pretty high for a Kolsch. Temp and time seem good to me.

Did you measure your ph at room temp? If so, corrected that would be a ph of 5.55 or so, which is just in ideal range, but for light beers like Kolsch I prefer a pH of 5.3, 5.2 for things like wits and weziens where I want a touch of tartness.

The mash pH is going to drive the pH the whole way through. Having a proper amount of acidity is important to achieve the right flavor profile.

PH was room temp. not sure what you mean by “corrected Ph”. the past couple batches Ph was spot on in the 5.3-5.4 range. I keep my ph meter in storage solution, though I have not calibrated it for several months. Fermentation started this morning, what kind of reading should I expect during early fermentation?

By corrected, I mean that there is a correction factor involved between pH at mash temps and pH at room temps. There is some debate as to the exact correction, but I have no problem taking Kai and Martin’s word for it. If you measure you pH at room temp to be 5.55 then you can assume the actual pH in the mash at sacharification temps will be about 5.3. Assume about .25 difference at sach temps.

As for beginning of fermentation, the boil will drive the pH down as well as the ferment.  The beer should finish no higher then 4.5 though I believe.