A little background. I have made close to two hundred racks of ribs in my MES smoker, mostly 3-2-1. My friends and I like fall off the bone and understand not everyone else does. My trick is to use an oven bag for all ribs instead of foil. I was concerned that the plastic bag could melt on the MES metal grate so I did put loosely wrap the bag of ribs with a foil; it was sort of like a foil boat for the bottom if that makes sense. I theorize the reasons why there is a significant difference between foil and oven bags is with foil you never seal it air tight and you don't get that pressure cooker effect.