DIY Fermentation Chiller using my mash tun and wort chiller

[tooldudetool]

So like many of you I have been looking for a simple, cheap method of fermentation control. I didn't want to look for a mini fridge with a temp controller as I already have a kegerator in the kitchen and a chest freezer in my bedroom closet that I use for cold crashing and cold conditioning kegs.

I found a couple of DIY water fermentation chillers here on HBT like this one: https://www.homebrewtalk.com/f51/water-fermentation-chiller-81501/ but it wasn't quite what I was looking for, although I certainly took some ideas from it.

My basic setup is to use my 10 gallon mash tun as the cold water chamber. I put frozen water bottles into the cold water chamber. I put my SS 3/8" immersion wort chiller into the cold water chamber. I put my bucket fermenter into a large rope handle tub that I insulated with 1.5" rigid foam on the bottom and 2 layers of reflectix insulation around the side. The raw end of my wort chiller tubing is shoved onto a tiny ebay submersible pump that sits on the bottom of the rope handle tub. The other end of my wort chiller tubing (with the female hose thread fitting) is clamped so that its near the top of the water level of the rope handle tub. The pump is plugged into my STC-1000 temp controller, with the waterproof temp probe located up against the outside of the fermenter in the rope handle tub. When the temp controller calls for cooling water is pumped from the bottom of the rope handle tub, through the cold wort chiller and back into the tub.

The best part of this setup for me was the simplicity and cost. I already had the mash tun and the wort chiller, and the only other things I had to buy were:
- STC-1000 temp controller off ebay for around $25 shipped. There are several threads on how to build this such as: https://www.homebrewtalk.com/f51/stc-1000-ebay-temperature-controller-build-330427/ I also had to buy a "project box" from Radio Shack for $9 plus a power cord and outlet for another $10 or so.

- Tiny aquarium pump from ebay: http://www.ebay.com/itm/US-Plug-AC-...572?pt=LH_DefaultDomain_0&hash=item2570993c3c for $6.50 shipped.
- Rope handle tub for $12 or so.

So basically everything for under $70.

The pump outlet has a tiny removable stub that fits the 3/8" ID tubing perfectly. I used plumbers glue to permanently fix the stub in place. I was afraid such a tiny pump wouldn't be able to push through the 25' of chiller and 25' of tubing, but it works great. It's definitely a slow flow, but that work out perfect to maintain the temp without overshooting it. I have to force water through the tubing to fill it before I hook it up because it doesn't have the power to push all the air out by itself.

I've been using this setup for a couple of months, and it works fantastic! I change out the water bottles in the morning before work and at night before bed. I feel that a liquid to liquid heat exchange is far more efficient and effective than a liquid to air exchange (like a fermentation fridge). Anyway, I hope this helps someone else out there make better beer. Brew strong!!

Here are some pics of the setup:

 

[Travestian]

Do you ever do more than one batch at a time? Seems like a good setup but only if you plan on fermenting only 1 batch at once.

 

[tooldudetool]

Yes, I can only do one batch at a time. I usually brew every weekend so it works just fine for me. I need the mash tun and wort chiller anyway for brew day. I really only need the fermentation chiller for the first 4 days or so anyway, after that sometimes I will shut off the temp controller and let the temp rise naturally to help finish out fermentation.

 

[kshuler]

great setup!

 

[william_shakes_beer]

Great idea. Seems like it would be simple to expand to 2 fermenters (with the same temp requirements) by swapping out the fermenter bath tub for a larger one.

By the way, if you add a 5 CF chest freezer and a brew belt you have permanent solution that requires no human intervention. You already did the hard part, which is wire up the temp controller to a pair of outlets.

 

[tooldudetool]

Right William, but as I mentioned in the post, I already have a kegerator in my kitchen and a chest freezer as my cold crashing/conditioning fridge in my bedroom closet (a very tight fit!). No room for more refrigeration! I do also feel that water to wort heat transfer is far more efficient than air to wort transfer, so I do feel like its superior to the typical fermentation fridge in that respect.