Originally Posted by mmb
The changes needed would be removing water from the mash and sparging the grain to boil volume after pulling the bag. I already have a three vessel system and tried BIAB because of the "simplicity" of the full volume mash and no sparge. Adding complexity to the process such as sparging would require another vessel to heat water in and needlessly complicates things. At that point, go two vessel with recirculation MLT/Kettle system.
I'll still BIAB and teach it for intro to all grain, but, in my opinion, 10G of a 1.040+ OG beer in a 15G pot is pushing the limits of the vessel.
There is really no need to heat the water for sparging. People who have tried both ways have found little difference between sparging with hot water compared to cold. You usually aren't sparging with a large quantity of water when you BIAB and the wet grains are hot enough to warm that amount of water enough to dissolve the sugars.
Wilserbrewer suggests adding hot water to bring your wort to mash out but that too is an unnecessary step as you achieve the same end by pulling the bag and begin to heat the collected wort immediately as you drain the bag and sparge.