[Thirsty_Monk]

I check mash pH about 10 min.. into the mash and that's pretty much it.  I may start checking kettle pH, just out of curiosity.

I also check pH of last runnings.

[denny]

I check mash pH about 10 min.. into the mash and that's pretty much it.  I may start checking kettle pH, just out of curiosity.

I also check pH of last runnings.

Being a batch sparger, I don't bother.  I did check for quite a while a long time back and never found the pH getting anywhere close to the "danger zone".

[hopfenundmalz]

If you fly sparge, you can also taste a sample of the runnings toward the end, and see if you detect astringency.

Got that tip from a few guys in the club.

[bspisak]

The colorphast strips are reportedly adequate but read approximately 0.3 too low.

That's about the difference you'll see due to temperature of the mash. Just like gravity, pH readings are temperature dependent. The "ideal" pH of 5.2 is at mash temp, which would make it 5.5 at room temp.

[a10t2]

That's about the difference you'll see due to temperature of the mash. Just like gravity, pH readings are temperature dependent. The "ideal" pH of 5.2 is at mash temp, which would make it 5.5 at room temp.

It's actually pretty neat. The offset more or less cancels out the temperature correction. So if you take a room temperature measurement and just read the strip directly you're actually reading the mash temp pH.

Anyway, what I generally do is check the pH with a ColorpHast strip (actually, half of a strip - they're plenty big enough to use each one twice) about 5 minutes after sealing up the mash tun. If it was off I'd use whatever salts I was holding back for the boil to correct it. So far I haven't had a mash that was far enough off to worry about though.

[bluesman]

I'm not sure if this was already asked or not.... What kind of water are you using?

Do you know or have you had your water tested?

Just curious because as redbeerman has stated high sulphate water can cause an astringency or high level of perceived bitterness.