I always use RO water to brew. I have never checked mash pH, but have become concerned since my brews have come out darker than predicted by BrewSmith.
I thought (I read in How to Brew by Palmer) that adding some DME to the mash will normalize mash pH; so that is what I have done.
Is RO water not the way to go? Or should I be paying more attention to mash pH on lighter beers? Is there a rule of thumb?