Originally Posted by Yuri_Rage

I use a steam system with a bit of automation. I find that I get hot spots very easily unless I stir during heating. I use a drill with a paint mixer attached, and I've noticed no problems. I just make sure that I quit stirring about 20 minutes prior to the sparge. Just before sparging, I use a March pump to recirculate the mash until it runs clear.

I average 80% efficiency and have been pretty happy with the system overall.