In 1997 Ken Schwartz published plans for the Son of Fermenation Chiller, an ice & fan based chilling chamber for fermenting wort.

After building a
Son of a Fermentation Chiller and using it for a while I found the following problems:
- It would only hold one carboy
- The analog thermostat sucked
- It is a PIA to deal with the ice in deep narrow ice chambers
So I redesigned the
controller first to use a digital remote sensing thermostat for under $25.
Then I redesigned the Son of a Fermentation Chiller to hold two 7½ gallon carboys and two ½ gallon growlers for my blow off tubes.
This is the layout of the chiller with one side removed and the top and front removed.
From this top view you can see enough room for two carboys and two ice bottles
Cut sheet from a single piece of
plywood foam:
Top closed:
Top open:
Front open:
The fan mounted in the right cooling chamber:
All three cooling chambers:
A tub full of ice in the central chamber:
Micah's version of the 38DD:
Awesome work, Micah!
All credit to the respective copyright holders.
- J Thornton
I will contact him about hosting his sweet thermostat page here.
Cheers!
edit: Done!
Cheers,
Chad
I used 1/4 plywood for laminating to the foam for the sides and top and I used some 5/8 ply for the base just because I had some on hand. Any size for the base from 1/2 up will be fine
John
John
Any chance you have the plans for how you cut the foam? If not no big deal..but if you did they would be nice. Great gadgets! Great Site! Keep it up!
The cut sheet is for the foam not the plywood. I cut and glued the foam together then skinned it with the 1/4" ply cut to fit as needed.
http://suburb.semo.net/jet1024/FermChill.htm
just scroll down to about the third picture
Enjoy
John
Craft stores have hot wire cutters (or you can make your own with a soldering gun), but I have found a big sharp chef's knife and a straight edge to work best!
Cheers!
My hot wire cutter is over 4 feet wide and will cut throug foam the entire length. So to cut through 2" polystyrene insulating foam (white blue or pink) which is 4' wide taakes about 2 seconds. the finished edge is better than the manufacturer's edge...
For more info google homemade hot wire foam cutters.
Where can I find the foam? I have been to my local Lowes and they have the blue stuff but it is only about 3/8" thick.
Thanks,
Rob
I like the modifications that you made to the design and the final product is actually pretty good looking. It looks like you were able to do the whole thing with one sheet of foam is that right? Do you recall what the total price tag was for the build? Thanks.
Cheers
Baron Ken, They are what is called acid carboys and they have a threaded top. These two were given to me and were found in a yard sale...
John
How low can you go with this? Is it possible to hit lagering temps? Wouldy post what the ambient temp was when you achieved your lowest temp? Also, have you used this going the other way to make the temp warmer during winter months? I like the idea (especially since it is cost effective).
nice build. I am going to attempt this weekend. I have 2 questions. What size fan did you use? What provides the structural integrity of the cabinet, the foam board or the plywood?
thanks,
Lou
Bluelou6, The fan I used was a 100mm but I don't think it matters much what size. Just so it blows the cold air up the tube. The foam will hold up on its own as in the SOF. The wood provides even more support and beauty.
John
This looks great !
You say it can hit lagering temps but not with ice. What would you use instead if not ice ?
Jim
PS- the advice to use PL300 adhesive is appreciated (works great), I used white poly beadboard foam w/ foil on one side- looks nice (wouldn't recommend it- pia to cut and foam beads everywhere,) If I build another I'd use blue or pink closed cell board.
John
John
Thank you sooooo much. Great work BTW!
The base is in two parts as shown on the plans. These must be edge glued together to form a 19 1/2 x 32 base.
John
I'm thinking of using the heating relay on the thermostat to trip a relay for a light bulb in one of the ice chambers for winter heating.
Any thoughts on that?
Thanks
I had a question on the shelf that the carboys sit on. It looks like you've extended that into the foam on the sides. Did you take it clear out to the outside plywood on the sides and attach it to that?
At first I was thrown off by the measurements on the front foam pieces. I thought they were off by 1/2", but I see that the foam fits on each side of the shelf. I was just going to have my shelf/cooling chambers sit in place on the bottom foam. Will that provide enough support to hold two full carboys? I'm sure your design makes a stronger, and probably more air-tight shelf.
Thanks for sharing all your designs with us!
Agreed I may modify mine - you can get a 6 to fit with blowoff as opposed to airlock.
Also anyone wondering why the hinged top as examples are shown without that it comes in handy for taking samples. Easier than sliding carboy out to sample.
Mine:
http: ( remove space ) //i53.tinypic.com/vya1de.jpg
Just be aware if you alter your ice section you will need to alter both front facing sections. As for containers with lower clearance you can use the shoe-box size plastic storage bins $1 each at walmart.
Again though 6.5 G carboy with airlock or 6 G with blow-off tube may be your easiest solution. Great project but dimensions need to be adjusted based on common carboy sizes not obsolete ones.
Any advice on how to hit lagering temp?
Cheers,
Mark G
Is there a blue print for the ice section, I have looked and looked but cannot seem to find one? Any help is most appreciated!
Thanks,
Eric
I have just finished my new 38DD, and was able to move my fermenting Lager (50 degrees) out of the "beer fridge". I made a few small changes to the design, but all in all it's a 38DD for sure.
Adds/Suggestions
- Casters
- CoolerGuys.com Fan and thermostat kit
- Tapered edges on foam to ease closing
Thanks, I was trying to take the easy way out and have someone else do all that complicated (sacasam) math for me. Once I put pencil to paper I had a workable print in no time. Felt like I was back in mechanical drawing class! As a greenhorn to home brewing I am learning very quickly to figure out solutions to problems on my own when I am able. Forums are great but can keep you from using your brain in moments of laziness , ergo my post above. Thanks for taking the time to lay it out for me, much appreciated!