[cmooreseymour]

Temperatures across most of the country are currently homebrew-friendly, but I'm already planning for winter.  I have a 7 cubic ft freezer in my garage with an external thermostat that I use to brew to temperature control my fermentation.  I can make the freezer as cold as I want, BUT I don't have a way to add heat to the freezer once garage temperatures dip below brewing temperatures.

I don't want to ferment in a closet and don't want to only brew lagers all winter.  Any ideas for safe, cheap ways to add heat to my garage freezer so I can keep fermenting at ideal temperatures all year long?  Thanks, guys.

[Stevie]

A lot of people use heating pads, reptile heaters (ceramic and pad), light bulbs inside paint cans. Loads of options. Paint can has always scared me, but people like them.

[eyousey]

I use a small fan in my freezer to keep the air moving around the bucket.  I've found, the hard way, that this small fan generates enough heat to easily heat the freezer into the 75-85+F range in as little as 12-16 hours.  While I'm fermenting, I leave the fan running all the time (plugged into wall).  The freezer will kick on/off as needed to hold the temperature.  When I'm ramping the temperature up/down, I have the fan set to only cycle when the freezer is running (plugged into temp controller).

[nbarmbrewer]

I made some heaters using some of this:
http://www.amazon.com/Flex-Watt-Heat-Tape-Watts/dp/B00AHEZF6S/ref=sr_1_1?ie=UTF8&qid=undefined&sr=8-1&keywords=FLEX+WATT+HEAT+TAPE

I went and bought a $3.00 extension cord from Walgreens and cut the end off.  They work pretty well. I made 3 of them for about $30.00.

[cmooreseymour]

Thanks, guys.  I think I'll look into the heat wraps or reptile heaters.  I'm a little weary of the light bulb/paint can or the cut off extension cord, but I bet they work.  I'm not sure if a fan would heat up a 7 cu ft freezer, but could be worth a try.  Any of these options would leave me wanting a thermowell vs my current copper probe taped/insulated to the outside of the carboy. 

Any additional ideas on how to heat up a fermentation freezer during colder months?

[klickitat jim]

Yes, I use Sunbeam heat pads. They have a low medium high switch. I use the large one. It works great in my 7cf and my 14cf with a Ranco controller. They are about $12 on ebay. Make sure you get one that does not have the timed auto-off switch. My freezers are in an uninsulated shop and it gets down to 20º at times. Pads work fine.bi just tape them to the interior freezer wall. I just did a sour beer where I wanted the beer at 95º for the first week. I tossed in a second heat pad that was running all the time and it held at 95º 24/7 even with 35º nights.

Whatever you decide to use, avoid things with too much mass and heat. Initially I tried a ceramic hot plate and it would get way too hot and took too long to cool off. The heat pads cool pretty rapidly because they dont have much mass. Good luck

[a10t2]

Assuming it's well-insulated, fermenting 5.5 gal of 1.050 wort would warm 7 cu ft of air by about 70°F. Keeping it warm shouldn't be an issue.

[eyousey]

Thanks, guys.  I think I'll look into the heat wraps or reptile heaters.  I'm a little weary of the light bulb/paint can or the cut off extension cord, but I bet they work.  I'm not sure if a fan would heat up a 7 cu ft freezer, but could be worth a try.  Any of these options would leave me wanting a thermowell vs my current copper probe taped/insulated to the outside of the carboy. 

Any additional ideas on how to heat up a fermentation freezer during colder months?

My freezer is a 7 cu. ft. and the fan worked fine (when I didn't even want it to).  A small ceramic heater, if you have one sitting around, will easily do the job too.

[tommymorris]

Assuming it's well-insulated, fermenting 5.5 gal of 1.050 wort would warm 7 cu ft of air by about 70°F. Keeping it warm shouldn't be an issue.

Are you saying if ambient was 40F fermentation would take the temp to 110F? That seems hard to believe.

Or are you saying that fermentation would supply enough heat to raise the temp by an aggregate 70F across the life of the fermentation? For the second case I mean, is the area under the curve (heat created versus time) 70F over several days? That seems possible but less helpful in a cold winter.

[a10t2]

Are you saying if ambient was 40F fermentation would take the temp to 110F? That seems hard to believe.

Assuming no losses to the environment, so obviously it will be somewhat less than that, but yes.

At high krausen a 5 gal batch is kicking out around 40 W.

[tommymorris]

Wow! That's a lot of heat. Anecdotal evidence, my can heater does turn on in the winter inside my 5 cu ft fermentation chamber. Maybe not as often as I thought.

Thanks!