To me mopping is about the texture of the rub and how it s behaving during cooking. A coarser rub forms bark better if you give a little bit of mopping along the way. If the rub is fine enough you can get pretty good bark from the moisture coming off the ribs naturally. A mustard slather helps in both cases. Of course cooking here at high altitude and low humidity, those can be contributing factors to my theory too. I just can't control for those variables to tell.
8/27/16 at 3:32pm