How can I use my old fridge for fermentation?

I have my old fridge in the corner of the garage.
I thought I might be able to use it to cool my fermenter, because its big enough for my 6 gallon one.


normally its about 6C (42.8F).
the problem is - how do I get it to the right temp?
I have a timer I can use on it's power line. I think maybe 15 minutes of work out of each 3 hours would do it.
I've asked an electrician and he said it won't damage the fridge

second problem - how stable do I need to keep this temp?
In this way I have ups and lows in the temp.
If my maximal and minimal temp (immediately after cooling session, and right before it) are in the acceptable range for ale fermentation, am I OK ? or would this constant change of temp do bad stuff to the yeast?

I'll be glad for any tip, although I don't think I'm up to modifying my fridge just yet.

Yeah those controllers work well. I just drilled a small hole in through the back for the bulb and then when I positioned it where I wanted it, caulked the hole.

ohad said:

second problem - how stable do I need to keep this temp?
In this way I have ups and lows in the temp.
If my maximal and minimal temp (immediately after cooling session, and right before it) are in the acceptable range for ale fermentation, am I OK ? or would this constant change of temp do bad stuff to the yeast?

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Your idea will work. Because of the mass, 5-6 gallons of wort will change temperature slowly. Experiment with a water jug until you get temperatures in the right range.

That being said, a temperature controller is the easiest way to control the temps in a refrigerator.

zoebisch01 said:

I just drilled a small hole in through the back for the bulb and then when I positioned it where I wanted it, caulked the hole.

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what bulb are you talking about? I don't understand...

desertbronze said:

a temperature controller is the easiest way to control the temps in a refrigerator.

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how does this kind of controller work? do I plug the fridge to it, and a thermometer inside the fridge controls the power?

where do I buy this kind of thing, and how much does it cost ?

thanks

You plug the fridge into the controller and put the temperature probe in the fridge. The controller cycles the power to the fridge as needed. Since the fridge 'wants' to be colder, it always runs when the controller gives it power.

Cost/availability depends on your location.

The bulb is the temp. probe.

Cost $55-$100

here's 1 source :

http://www.midwestsupplies.com/products/ProdBySubCat.aspx?SubCat=620

Also keep an eye on ebay sometimes you can find them cheaper

http://cgi.ebay.com/Homebrew-Draft-...ryZ38172QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I think I got to a stable temp between 19C and 21C.
2 hours and 45 minutes off, for every 15 minutes of work with my fridge.

after puting the batch in the fridge I saw that I need a long cooling period (few hours) before the wort will chill down to 20C (started at 30C).
after that I got to a stable temp when working 30 minutes for every 2:30 hours idle.
I really hope this brew goes well...

If you're using a timer, you're going to have to tweak it whenever your garage ambient temps change significantly.

You're always going to have this fear that it's cycling too much or not enough.

If you've set a price on NOT having that feeling and it's about ~$50 USD, it's time to give an analog controller a look.

What does the controller do to the Freezer section of the fridge? I would assume that it keeps it the same temp as the rest of the fridge.

Pirate Ale said:

What does the controller do to the Freezer section of the fridge? I would assume that it keeps it the same temp as the rest of the fridge.

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the freezer just runs when the fridge runs. what I did is cut a big hole in the wall between the fridge and the freezer to help the fridge cooling.
JJ

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270107910907

Why go analog?

CplHunter said:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270107910907

Why go analog?

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No particular reason other than...
In general, the most widely available analog conroller built by Johnson Controls, is already wired. In my experience many of the Ranco digitals are not wired (but some are). Alot of folks here have trouble with the wiring. I've seen a few threads...

That's a decent price though.

Jaybird said:

the freezer just runs when the fridge runs. what I did is cut a big hole in the wall between the fridge and the freezer to help the fridge cooling.
JJ

Click to expand...

Pics or diagram of where and how you cut the hole would be cool....