Fritz-
I am planning to brew an Anchor Steam clone this weekend myself. I have 10 G of porter to drink (FG at around 1.018) and I had hoped to have a nice clean "lighter bodied" highly attentuated beer as a counter balance to my porter. I considered leaving the carboy to ferment in the garage (~45 F) but when I spoke to John Plise at B3 (Morebeer.com) he recommend a fermentation temp of closer to 60 F. Apparently, the yeast need just a little warmth to get going strong. At garage temps, John thought that the fermentation time would take 4 weeks.
Question: Are you still going to try and let the beer "lager" for a couple of weeks?

