Got in a brew a couple days ago before the multi-day string of sub-zero temps hits. Brewed 11 gallons of ESB, half traditional, and after pulling that half through the chiller, added 4 oz of Mosaic and whirlpooled for another 20 minutes. Both halves are fermenting with Wyeast West Yorkshire, the ESB at 68F, the Mosaic at 63F.