I have been using a fermwrap heater to keep my ferments at the right temp. My carboys are out in the garage, in a rubbermaid bin and insulated with old towels. The fermwrap has done a great job at letting me dial in my fermentation temps. I wish I had bought this years ago. It has made winter brewing much more managable. I might actually miss it in the summer months. I figured I’d include a few pics so you can see how its taped to the glass carboy and what it looks like on its own.

I am using a digital single stage temp controller. With the ambiant temperatures being much colder than my ferments (62-68F) I have been able to do what I want with total control. I was chilling to 55-60F and pitching my yeast. Then I’d set the controller to use the fermwrap and bring the temp up to 65F. Ferment would naturally want to go to 68F but that was cool. Then 5 days into the ferment I’d ramp the heater up to 70F to get the beer to really finish out and dry out as much as possible.

I had a little difficulty the first time I used it. The temp would swing up way above what I wanted and not come down. I think that was more a function of a vigorous ferment and too much insulation around the carboy. I recommened using a wider differential during the early days so it doesn’t overheat the beer. Then I would tighten the control setpoint to only 2 degrees and that seemed to prevent accidentally over shooting my desired temp.

Definitely give a fermwrap a try to control temps during the cold months. In the summer I may have to try this with a carboy jacket of some sort in the fridge. Seeing how I have two fridges on temp control, I’ll need a third one to control the fermwrap… we’ll see this summer how I decide to run it.

BREW ON!