Lagerators/freezers in garage in cold-weather winters

Is it viable to use a fridge or chest freezer in a garage in a cold-weather climate for cold fermenting/lagering, or is the ambient temperature in the garage too much to overwhelm the insulation of the lagerator re: controlling temps from 55* down to 40*? I did some searching on the forum but didn't really come across anything.


Also, if you're lagering in a chest freezer, is it a big deal to bump the temp back up to fermenting range if you throw a new batch in, and then back down to lagering temps when fermentation is complete?

Well, it's all about temperature differential. Let's say you want to ferment at 50dF. If your garage is constantly down in the 30s, the freezer won't turn on and will eventually come to an equilibrium with the garage temp, despite the freezer insulation. If your garage doesn't get lower than the mid 40s, I'd say go for it. Just leave a thermometer out there over night (on a super cold night) and check it first thing in the morning. That should be about as cold as it will get, unless it gets arctic outside. If your garage is attached to your house, it will stay warmer than a detached garage.

As for fluctuating lagering temperature to accomodate a new batch primary fermentation temperature, I wouldn't do it, but it won't kill it. It would be less significant if you fermented the new batch cold, like in the upper 40s. However, yeast don't like sudden and significant temperature changes, so I'm not sure what the impacts would be.

Here in Austin, temps will drop into the 30's a few times a year, but they will also drop into the 40s at night for a couple of months during the winter. Here's what I use for my fermenter. It cost about 6 bucks for the cheap extension cord, light bulb socket that plugs in, and a 25 watt vanity light bulb. I leave it on all the time and the freezer will cycle to keep 60 degrees. Works like a champ. I remove it when temps warm up in the Spring, Summer, & Fall.

I use a small ceramic space heater in my fridge hooked up to a ranco temp control. I tried the light bulb trick until I opened up the door one day to a broken bulb melted into the bottom of the fridge! (operator error to be sure - had a lamp in there that fell over )

Thanks for the info. I'd heard the light bulb idea and I think that might be my best shot - was just curious if there were any other ideas that didn't involve more (although 25W bulb isn't a whole lot) tax on the electric bill.


Back story behind this - I'd rigged up a mini-fridge as a lagerator (pics in the equipment thread somewheres) but in trying to make space for a blow-off setup, I killed the fridge...whoda thought that stinkin tray cooled the whole thing? (I'm not terribly smart). What's funny is we'd had a bock sitting in there for a week at 55 with no action/no change in gravity. We had a smack pack burst incident to start off with, so I was hoping the yeast had been rendered dormant and we could re-heat, ferment, and cool at some point in the future.


Well...I looked in the fridge shell today and she's fermenting. At about 65* currently. Now I'm in a time crunch to save the bock. Yeesh...moving it to the garage.

I used a stick on reptile heater. It's just a rectangle shaped pad that gets warm that I stuck to the side of my fridge.

I think it's about 15 watts, which is not much but if you are concerned about electricity, you can unplug the fridge altogether and use a temp controller for your heater. That's the most energy efficient method. Of course, you have to make sure garage does not get warmer than the set temperature...

Do you have to worry about damage to the freezer's compressor if the temp in the garage is in the 40s while you are fermenting at 60? Obviously not if you unplug the freezer and just hook up a heater to a temp controller. What if the temp in the garage gets down to the 30's?

...but if you are concerned about electricity, you can unplug the fridge altogether and use a temp controller for your heater.

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Assuming you're using the same analog controller: Wouldn't that turn the heat on when it gets 'too warm' and leave it on (letting it get warmer and warmer) and not ever turn the heat on if it was 'too cold' (letting it get colder and colder)?

We use a Ranco temp controller on our fermenter. We just set it to the heating mode in the winter. You can use just about any heat source. We thought about a light bulb but decided against it because we ferment in carboys. So we've been using an old hot plate with a tight temperature range.

SpanishCastleAle said:

Assuming you're using the same analog controller: Wouldn't that turn the heat on when it gets 'too warm' and leave it on (letting it get warmer and warmer) and not ever turn the heat on if it was 'too cold' (letting it get colder and colder)?

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Most if not all analog temp controllers can be used for heat mode or cooling its just a change in wiring inside the unit.

springer said:

Most if not all analog temp controllers can be used for heat mode or cooling its just a change in wiring inside the unit.

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Very important detail. The way it was worded it just said to unplug the fridge and use the controller for the heater.

Ya I can see how it would be confusing the way it was written.

springer said:

Most if not all analog temp controllers can be used for heat mode or cooling its just a change in wiring inside the unit.

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Build up a proper wireing harness and you can convert the Cooling only digital controllers into Heating or Cooling without even opening the controller. The output from the controller would have to be plugged into the harness. The harness into the wall for its own power supply, and into the heating element.

When the Controller commands the cooling on the heating element would turn off.

Is there any risk of damage to the freezer's compressor if the freezer is kept in a cold garage and is NOT unplugged during the cold winter months?

I use a small hair dryer, hooked up to the temp controller, in my fermenting freezer when it gets cold outside. The heating element if fairly well protected, so it's not going to melt anything. Plus, it has a fan, so it quickly gets the temperature back up to what I need. Typically, it only kicks on for about a minute or less at a time.


TL

ewhite2003 said:

Is there any risk of damage to the freezer's compressor if the freezer is kept in a cold garage and is NOT unplugged during the cold winter months?

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It would be the same as if it was unplugged. It'll never run if the internal heat doesn't get above the set point.