I’ve seen a lot of homebrew systems in my travels but this one actually made me extremely jealous. Fermentation temperature control to within a tenth of a degree!? What more do I need to say?
Brew Pi: The Future of Homebrew Fermentation
This Pimp My System project was submitted by AHA member Chris Allen. Calling Nashville, Tenn. home, Allen has immersed himself in the vibrant homebrew and craft beer community in Music City, and is dedicated to mastering the art and science of beer making.
Having purchased two 14.5 gallon conical fermenters, I knew that my garage was the next logical space to spill into. In order to park a car in our garage, purchasing the correct size refrigerator fermentation chambers was key.
It turns out, the same glass door refrigerators that you buy a soda out of in a convenience store, True GDM-12, were a perfect fit for the garage wall and the conicals. I installed casters onto both refrigerators to make it easier to shift beers around during primary or secondary fermentations. I didn’t realize how awesome using a glass door refrigerator as a fermentation chamber would be—being able to visually see active bubbles in the blow off container is a nice luxury.
I initially connected the two refrigerators to their own Johnson Control A419 controllers, but was never truly happy with them. I didn’t like that they were only single stage, which meant I had to take off the cover to switch it to heating when necessary. In the fall or early winter this presented a challenge due to temperature fluctuations mid-day.
The Solution: BrewPi
With my background in electronics and love for computers, I decided to take fermentation to the next level using BrewPi controllers. BrewPi controllers consist of an Arduino, Raspberry Pi, solid-state relays and other breakout circuit boards. They are basically fermentation controllers on steroids.
While most PIDs function to control the mash in HERMS or RIMS type setups, BrewPi incorporates its own PID algorithm to control fermentation. Without a doubt, BrewPi can hold active fermentation within a tenth of a degree. I almost can’t believe the accuracy of control I am able to achieve with BrewPi.
Need a diacetyl rest? No problem. Having trouble getting your pitching temperature precisely? No problem. Want to do crazy multi-step temperature profiles over several days? No problem. The BrewPi is so dynamic and consistent that the resulting quality in my beers has been amazing.
I currently have three temperature probes connected to each BrewPi. The first probe placed inside the conical thermowell reads the actual beer temperature. The second hanging in open air inside the fermentation chamber reads the chamber temperature. The third sits on top of the BrewPi case to monitor the ambient air temperature inside my garage.
BrewPi is managed through a web interface. I can be sitting in bed and watch the linear graph showing the temperature of the fermentation chamber and the thermowell. With BrewPi, you can start and stop fermentation control using the web interface. Temperature profiles can easily be downloaded for backup or Excel manipulation.
Modifying the fermentation chamber was quite challenging. Even though soldering the components and circuit boards from the BrewPi kit took very little time, soldering and routing the wire connections in and around the refrigerator was very time consuming. The overall BrewPi build for one refrigerator took anywhere from two to three evenings.
There are so many ways you can connect a BrewPi to your refrigerator. I took what might have been the hardest route and re-routed wires through the refrigerator floor and wiring harness channel. I also modified the original thermostat cover plate and drilled three holes, one for the heater connection, and the other two for the thermowell and fermentation chamber temperature probes.
The process of incorporating a BrewPi into any fermentation chamber project is as difficult as you want to make it. The easiest route would be to connect the solid state relays to standard wall plugs, similar to how a STC1000 is wired for temperature control. Once the BrewPi kit is built, the Arduino and RaspberryPi will need to be configured. Brewpi.com has great detailed instructions on how to do this.
Reading the Full Article will change the way you think about your fermentation system. I would kill to have one of these !