Image by :
[Quinn Dombrowski][21]. Modified by Opensource.com.[CC BY-SA 4.0][22].
The only other thing I needed that was a little tricky to find was a compression fitting for the temperature probes. The probes were mounted in T fittings before the valve on the lowest bulkhead in both the HLT and the mash tun. As long as the liquid is flowing past the temp sensor, it's going to be accurate. I thought about adding a thermowell into the kettles as well, but realized that's not going to be useful for me based on my brewing process. Anyway, I purchased[1/4" compression fittings][34]and they worked out perfectly.
### Software
Once the hardware was sorted out, I had time to play with the software. I ran the latest[Raspbian distribution][35]on the Pi; nothing special was required on the operating-system side.
I started with[Strangebrew Elsinore][36]brewing software, which I had discovered when a friend asked whether I had heard of[Hosehead][37], a Raspberry Pi-based brewing controller. I thought Hosehead looked great, but rather than buying a brewing controller, I wanted the challenge of building my own.
Setting up Strangebrew Elsinore was straightforward—the[documentation][38]was thorough and I did not encounter any problems. Even though Strangebrew Elsinore was working fine, Java seemed to be taxing my first-generation Pi sometimes, and it crashed on me more than once. I also was sad to see development stall and there did not seem to be a big community of additional contributors (although there were—and still are—plenty of people using it).
### CraftBeerPi
Then I stumbled across[CraftBeerPI][39], which is written in Python and supported by a development community of active contributors. The original author (and current maintainer) Manuel Fritsch is great about handling contributions and giving feedback on issues that folks open. Cloning[the repo][40]and getting started only took me a few minutes. The README also has a good example of connecting DS1820 temp sensors, along with notes on interfacing hardware to a Pi or a[C.H.I.P. computer][41].
On startup, CraftBeerPi walks users through a configuration process that discovers the temperature probes available and lets you specify which GPIO pins are managing which pieces of equipment.
CraftBeerPi (photo by Christopher Aedo.[CC BY-SA 4.0)][8]
Running a brew with this system is easy. I can count on it holding temperatures reliably, and I can input steps for a multi-temp step mash. Using CraftBeerPi has made my brew days a little bit boring, but I'm happy to trade off the "excitement" of traditional manually managed propane burners for the efficiency and consistency of this system.
CraftBeerPI's user-friendliness inspired me to set up another controller to run a "fermentation chamber." In my case, that was a second-hand refrigerator I found for US$ 50 plus a $25 heater) on the inside. CraftBeerPI easily can control the cooling and heating elements, and you can set up multiple temperature steps. For instance, this graph shows the fermentation temperatures for a session IPA I made recently. The fermentation chamber held the fermenting wort at 67F for four days, then ramped up one degree every 12 hours until it was at 72F. That temp was held for a two-day diacetyl rest. After that it was set to drop down to 65F for five days, during which time I "dry hopped" the beer. Finally, the beer was cold-crashed down to 38F. CraftBeerPI made adding each step and letting the software manage the fermentation easy.
SIPA fermentation profile (photo by Christopher Aedo.[CC BY-SA 4.0)][9]
I have also been experimenting with the[TILT hydrometer][42]to monitor the gravity of the fermenting beer via a Bluetooth-connected floating sensor. There are integration plans for this to get it working with CraftBeerPI, but for now it logs the gravity to a Google spreadsheet. Once this hydrometer can talk to the fermentation controller, setting automated fermentation profiles that take action directly based on the yeast activity would be easy—rather than banking on primary fermentation completing in four days, you can set the temperature ramp to kick off after the gravity is stable for 24 hours.
As with any project like this, imaging and planning improvements and additional components is easy. Still, I'm happy with where things stand today. I've brewed a lot of beer with this setup and am hitting the expected mash efficiency every time, and the beer has been consistently tasty. My most important customer—me!—is pleased with what I've been putting on tap in my kitchen.
### [aedo-f6.png][16]
Homebrew on tap (photo by Christopher Aedo.[CC BY-SA 4.0)][10]
_This article is based on Christopher's OpenWest talk,[Brewing Beer with Linux, Python and a RaspberryPi][18].[OpenWest][19]will be held July 12-15, 2017 in Salt Lake City, Utah._
Christopher Aedo - Christopher Aedo has been working with and contributing to open source software since his college days. Most recently he can be found leading an amazing team of upstream developers at IBM who are also developer advocates. When he’s not at work or speaking at a conference, he’s probably using a RaspberryPi to brew and ferment a tasty homebrew in Portland OR.
