It's been a while since I've done an all-grain dark beer (I know, shame on me). I like the benefits I've read and heard about when adding dark grains at vorlauf instead of including them for the full mash. Things brings up a couple of questions on how to approach this for the way I brew:
1) I use a pump and sparge arm to continuously recirculate during the mash, so I don't really do a traditional vorlauf step. Should I add the grains XX minutes before mash out, during mash out, add after mash out and let rest before sparging, or some other technique?
2) Water adjustments - should I only factor the base grain(s) when using the Bru'n Water spreadsheet or still adjust using the total grain bill? I would guess that I'm still using the total grain bill, since I'll be sparging all the grains and want the sparge water pH correct. But, with the late addition, the initial pH will be different, maybe?
Any technique help (other than telling me to completely change my system) would be greatly appreciated!