DIY Beer Fermentation Automatic Temp Control (Chiller)

I recently got back into home beer brewing. But I noticed that I had a problem with fermentation temp control with the gear I had on hand. One of the keys to good beer it fermentation at 68-70° F.

A lot of the beer community seems to wrap the fermenter in a thermal blanket, and chill it with a cooler of ice water. Seems like a lot of steps to me. I then found a device that seems to use a Pelteir with an aluminum rod to regulate the temp of the beer….but it is $350! OUCH! Kind of pricey for “home brew”.

So I decided to make my own. I have played with Pelteirs in the past. Went to amazon and ordered a 12VDC Peltier and heat sink combo, along with a 12VDC digital temp controller. The found a aluminum rod on Ebay, even had a 5/16 tapped hole in the end! All for under $50. I designed a case for the thole thing in Fusion 360, then 3D printed it…13 HOUR PRINT. I also replaced the controllers screw terminals with removable screw terminals.

Once I got all my parts in, I had to modify the heat sink to work with aluminum rod. Then did some tests with the new set up in a 2Gal water cooler jug. Which will be my new fermenter! This should help keep the beer at a more steady rate. So no need to wrap a carboy in a thermal blanket! The tests keep the water within 1° F of the target, which was set to 67° F. While the beer is fermenting, it may have to work a little harder to maintain due to the heat generated by the yeast. That test yet to come.

I am planing on making my own PIC based controller with some features that the DIY  and commercially available one does not currently have.

Cheers! 🍻