Fermentation question

Hello all,

I am having a really crazy stupid thought here. I would like to brew in the winter time. I also unfortunately keep my house extremely cold during the day when I am not home to save on cost. I know that fermentation temps for ales SHOULD be in the 60-70F or so range. Probably not going to happen in my house. So my thought is would it potentially work if I fill a plastic tub with water and put the filled carboy in the tub and then have a fish tank temperature controller in there to keep a constant temperature. Would that work? I also have a chest freezer that is currently not being used so is there any way I could easily get a constant temperature in the chest freezer warm enough to ferment ales until I am ready to use it for lagering? Just looking for some cheap ideas. Thank you


I would use the freezer. Add a external dual temp controller (RANCO or such). Put the compressor on one side and hang a 100W incandescent light bulb in a can on the inside of the freezer off the other control. This will allow you to keep your temp constant.

Temp controllers aren’t too expensive. between $70 and $110.


I would use the chest freezer, too, but if cheap is what you want, using a fish heater in a big container of water is the way to go. If you have an aquarium pump you could use that to help circulate the warm water, too.

I built a box out of foam insulation and use a temperature controller in conjunction with a cheap hair dryer to regulate the temperature. I’m in a pretty unique situation, though, since my basement doesn’t get above 54°F even in the summer. If you know now that you’ll want to both heat and cool fermentations eventually, I’d spend the money up front and go with SlowBrew’s suggestion.

I don’t understand what he is saying. I cannot picture in my mind what he is asking me to do. I do have a Johnson analog controller already.

He’s saying that you can buy a two-stage controller (this one, for example
) and plug your freezer into the cooling circuit, then plug some sort of heating element (light bulb, reptile heater, hair dryer, etc.) into the heating circuit. The controller would then heat OR cool the inside of the freezer as needed to maintain your desired temperature.

The Johnson A419 can only cool, so it wouldn’t do what you need in either case.

How do you heat your house? For me its cheaper to maintain a constant temp. I would set the heat for the low 60s and keep it that way.


Otherwise you use tons of energy reheating the space every night when you return. Of course, if you drink enough beer, you won’t feel the cold.

just wondering how your wife feels about being touched by your ice cold hands.

(let me guess…you don’t have a woman…and you can’t figure out why).

During the winter, I put my carboy in a big tub of water with a fish tank heater and circulator pump to temperature control my lagers. I put the whole thing in the basement bulkhead area where it is unheated. I use a temperature controller with a thermowell in the carboy and that controls the fish tank heater. I can hold 48 degrees for as long as I need to.

Granted, but it’s still cheaper than paying someone to sit at home and feed the stove all day.


Otherwise you use tons of energy reheating the space every night when you return. Of course, if you drink enough beer, you won’t feel the cold.[/quote]

“When I heated my home with oil, I used an average of 800 gallons a year. I have found that I can keep comfortably warm for an entire winter with slightly over half that quantity of beer.” -Dave Barry

I use a fridge with a tiny oil fin heater inside. The heaters’ thermostat controls the temp inside the fridge.


Otherwise you use tons of energy reheating the space every night when you return. Of course, if you drink enough beer, you won’t feel the cold.[/quote]

I’m curious if you have any information on that. There’s got to be a trade-off between setting your thermostat lower & re-heating upon return, and keeping a constant-temp. You’re suggesting there’s a too-cold point where re-heating isn’t cost-effective; at what point is that?

That isn’t a difficult question, mathematically speaking, but you need to know the cost of your heat source, the volume of the room(s) being heated, the desired temperature, the outside temperature, the R-value for your walls, floors, and ceiling, and how long you’ll be away.

I use a 15w light and just let my analog contorted chest freezer fight with it.

+1, I use a 25 watt bulb, the type that looks like a fake flame.The bulb is in a drop light that is placed in the bottom of my fridge where the drawers used to be. Then I take some aluminum foil and tape it to main shelf so it hangs down and covers the bottom to protect from light.This has worked well in the winter when the basement temps get below normal fermentation temps.I set the analog controller four degrees below my desired ferm temp, this seems to work for the four degree temp spread on these analogs. cheers, Mike.