Brewing salts (and a pH question)

[Chorgey]

I'm new at water chemistry and have some questions.

I'm doing BIAB, not sure if this changes the answers.

When do you add brewing salts? To the strike water before turning on the heat?
I've read that someone adds salt the night before brewing. Is there a tried and true way to mix/dissolve the salts (Gypsum and Calcium Chloride)?

It seems that I should take a pH reading about an hour after I have added the mash. Question is, if I need to wait for the wort to reach room temperature to get an accurate pH reading, how would I do any adjustments? I mean, while I'm waiting for the sample to cool down to room temperature, the wort in the brew kettle should be heating up to a boil at this point. Am I over thinking this?

 

[Carolina_Matt]

When I looked into water chemistry with BIAB, I remember reading that you can just put the gypsum and calcium chloride on top of the grains in your brew bag. When you lower the bag into the water and mix up the grains, the brewing salts get mixed sufficiently.

 

[balrog]

I add the salts when I add the water to the BIAB kettle. They're in there while heating to strike temp. I take a sample in a big syringe at 30min after dough in, allowing it to cool prior to measuring and cool without evaporation which would alter the sample. There is quite the debate on pH over the length of mash but it should be settled by 30m -- you should see for yourself.

 

[ScrewyBrewer]

I prepare my mash strike water by adding salts and acid as needed the night before brewing. And for consistency take the mash pH readings, cooled to 77F, at 30 minutes into the mash.