Adit’s Foam Fermentation Chiller

Inspiration:

I live in Florida and my apartment is usually at 78F. I brewed my very 1st batch a couple of weeks ago (a simple amber ale) using a swamp cooler and frozen bottles of ice. It got the job done, but it wasn’t ideal. I had to add just enough ice bottles to cool the fermenter without overdoing it and crashing the yeast. This meant constant monitoring and still resulted in large fluctuations in temperature, from 63F to 70F depending on when I got home from work to replace the ice. Thus, I decided to build a fermentation chiller.  I had read about the Son of Fermentation chiller but decided that I wanted something that could cool down to lager fermentation temps more efficiently.  Thus I decided to use circulating water instead of air to cool my fermenter.

Design:

There are 2 insulated boxes glued to each other with a hole between them.  Box 1 is the cold sink, filled with cold water and ice bottles.  A water pump with a hose is also in box 1 and plugged into a temperature controller.  Box 2 contains the outlet for the hose, the temperature probe, and the fermenter.  When the temperature of the water around the fermenter reaches a certain point, the temperature controller kicks on the pump.  This in turn pumps ice cold water into box 2 until the temperature drops to an appropriate degree.  Any excess water in box 2 flows back into box 1 through the hole.

Materials:

For construction materials, I opted for simplicity and low cost.  I bought the STC 1000 and a cheap aquarium pump online.  Wiring for the temperature controller, tubing, 2 foam boxes, large garbage bags, and adhesive can be found at your local grocery or home improvement store.  All in all, it cost me around $65 to build from scratch.  Construction was very minimal. It involved gluing the 2 foam boxes together and drilling a 3” hole in between them.  I duct taped garbage bags inside the boxes to prevent the foam box from leaking.  Do note that I built this to accommodate a 3 gallon better bottle.  Larger setups will require modifications.

How it works:

While not as hands-off as a freezer or fridge, this system is much more stable and controlled than the swamp cooler method.  I am able to get ale fermentation temperatures by replacing the ice bottles every 2 days.  I am also able to get lager fermentation temperatures by replacing them every 12 hours.  Fluctuations in temperature are within +/- 0.5 degrees, and the temperature of the water in the chiller is very close to the temperature of the beer.  This is ideal for someone who wants a compact and affordable system that they can haul into a closet.   It’s also nice for someone who wants to eventually get a fridge or freezer (since you will need the temp controller anyway),but hasn’t found that good deal on craigslist yet.