Temperature contolled swamp cooler

I recently saw a post where someone had rigged a temp controller to pump the water from their swamp cooler through a chiller in an ice bath and back into the swamp cooler. Seemed like a reasonable system for the budget minded, so I decided to start looking for the equipment to make it happen. I needed a chilling system anyway and had been looking at the General Lee system from Jaded Brewing, designed especially for places with warm ground water. I think Houston qualifies! For a temp controller, I have been reading good things about the InkBird unit, which sells for around $38 on Amazon.

About two weeks ago I was reviewing Craigslist and what did I find, but a guy selling a used General Lee system, compete and in good working order. In addition, he had a 6.5 gal Big Mouth Bubbler. I had been thinking of getting one of those too.

I had been planning to set up the system with the carboy inside of a 60 quart Igloo cube cooler to hold temps as long as possible. But after getting the Big Mouth home, I realized that it was narrow enough to fit inside of my 10 gallon Igloo hot liquor tank, with about an inch or two of space for the water needed to maintain the temps. With a Brew night planned for this weekend, I quickly placed an order for the needed InkBird controller.

Well, this afternoon I got the whole system set up. Currently I am only measuring the water temp around the carboy. I have the InkBird set to turn the pump on when the water reaches 66 and run until it's down to 63. At this time I'm not able to easily determine the wort temp, but I should be in the 64-68 range, which works for now. The system has only run twice since I got it running about 4 hours ago, and it takes about 5 or so minutes to drop the water from 66 to 63.

Next update is to obtain a two hole lid for the Big Mouth and a thermowell so I can run the Inkbird probe down into the wort, instead of measuring the water around the carboy. At that time I will probably narrow the temperature range from 3 degrees down to 2, or maybe even 1.5. I will also look into fabricating something to insulate the top of the carboy/igloo cooler better than a wet towel.

Hopefully this post will help someone else who also wants to control their fermenting temps on a budget.

PianoMan said:

Tx, please post the inside temps during fermentation when your able. I'm very curious the delta to the surrounding water. Looks like you 1 up'ed it! Thanks for sharing!

Click to expand...

I moved your comment to this thread, since I've jacked the other one enough already.

I'm going to guess that it's not more than 2-3 degrees above the water temp. My reasoning is the length of time it takes to warm the water around the carboy from 63 to 66 degrees. My observations yesterday were that it took over two hours for the fermenting beer to raise the water 3 degrees. Once I get the thermowell, I will also put another thermometer in the water so I can get some comparative amounts.

Looks nice. Interesting wort chiller -- it's almost like a Celtic knot.

Are you only using that to cool the incoming water? Or have you used in to cool wort too? I feel like it might work well, but on the downside restrict you from stirring or doing a whirlpool.

Resonator said:

Looks nice. Interesting wort chiller -- it's almost like a Celtic knot.

Are you only using that to cool the incoming water? Or have you used in to cool wort too? I feel like it might work well, but on the downside restrict you from stirring or doing a whirlpool.

Click to expand...

Yes, I used it Saturday night. The pump is fairly low pressure and moves about a gallon per minute. About 4 gallons of groundwater (85 degrees?) dropped it from boiling to 170. I then did a 20 minute whirlpool and had room in my kettle to stir. The whole thing is pretty compact, and I have a reasonably wide kettle. At the end of the whirlpool I was just under 150. About 8 more gallons of water and 15 lbs of ice got me under 80. I should have used less ice early and saved more for later and I think I could have gotten under 70. Their web site claims it will do 200 to 68 in 16 minutes with 80+ degree groundwater.

Thought I would post an update. I am really thrilled with this little system. During active fermentation it took about two hours for the water temp to warm from 63 to 66. Then when it kicked on, less than two minutes to cool back down to 63. By day five the ferment had settled down and I bumped up the bottom temp to 64. Actually, I never got even close to a blow off, something I have always experienced with my previous brews. I'm assuming the active temperature control had a big impact on preventing any thermal runaway, which in turn, I assume can create a blow off.

I believe on day six I bumped to 65 or 66. (bad memory) On day seven I took a gravity reading (down to 1.015) and tossed in a muslin bag with 1.5 oz of dry hop. Every day or so I've upped the temp by a degree. Yesterday morning I took out the first dry hop and put in a fresh 1.5 oz. Once I got the setting above 68, the pump almost never runs. Seems to settle in about 1.5 degrees above wherever I have it set. I've kicked it on manually a couple of times just to be sure the water is being circulated some. Last night and this morning it was holding steady at about 70.5 degrees, and I bumped the bottom temp up to 70. I have also tightened the range from 3 to 2 degrees.

I'm really happy with this system. Only thing I would change is to have a quieter pump. This one is pretty annoying. Luckily it doesn't run very often, or for very long, but it still bothers SWMBO. Later this winter I will move it out to the garage and take a shot at my first lager. I imagine that will require the pump to run quite a bit. Probably brew up a dopplebock. Anybody have a good Salvatore recipe?

Well, I had to go and mess with things. After two successful batches with the original setup, I picked up a 16" thermowell and a two-hole top for my Big Mouth Bubbler, and now I have a new problem. I am now measuring the beer temp, instead of the water temp, and by the time the beer starts cooling, the water in the Igloo is so cold that I end up over-shooting my goal and the beer ends up two degrees colder than I wanted it.

If you'd like to help me resolve this issue, please check out my new thread:
https://www.homebrewtalk.com/showthread.php?t=556106

Thanks!