I've been brewing for about 6 months now, ales only. I just bottled an extract kit London Porter, my second London Porter kit. All my fermentations have been in the back room of my house. I have a digital thermometer with probe against the outside of the carboy and prior to this last batch the temps have been in the high 60's low 70's. This batch has been fermenting at low 60's. My starting grav was .053 and finished at .021 fter 3 weeks in the carboy. This is different than the other batches. Could the colder temps affect the ale yeast and not make it as efficient? The bubbler was active for less than a week.