Up until now I have managed by mash pH by estimating the residual alkalinity in my water used for mashing vs the grain bill. I have done this by using Brun water. I have adjusted my water in advance by dilution with RO water, campden and then mineralization by gypsum, epson and calcium chloride. My water is very alkaline, so I don't have to add bicarbonate to the water, the dilution is basically to lower the Nacl (which is high) and bicarbonate so that I get the right RA value.
I haven't been monitoring the mash pH to confirm if Brun waters predictions are correct, but I have purchased a pH meter for my next batch. I am familar with using a pH meter as I have used one regularly at work.
So my question is how do you go about adjusting mash pH on brew day if the pH is out of the optional zone?
A lot of brewing literature seems to glaze over the practical side of this. But I assume you can do it one of two ways;
1) Add a acid (or base) like you would for sparging water
2) Add CaSO4 or NaHCO3
Now how exactly do you go about this? Is there a guide on the quanities required?
Or am I going about this all wrong, should I be adjusting my waters mineral profile once I have doughed in?