I recently did a sour mash Berliner using my eBIAB setup and it worked very well. I set my PID to 100*F and left it covered for 24 hours. (I was a little apprehensive to leave it on unattended, but I didn't have any problems.) Next time I make a Berliner I am going to let it go longer, since this one wasn't as sour as I would have liked.