I do 5 gallon all grain batches using a 16 gallon Bayou BK, a 10 gallon water cooler mash tun, and a burner. Eventually I'd like to upgrade my equipment to electric with either a RIMS or HERMS setup, and make some sort of automated system. I've been researching a lot on controllers, but all the information out there is still somewhat fuzzy to me in terms of what they can or cannot do.

For example:

  • Can BrewPi (or something similar) control the electric kettle(s)?
  • When creating your own DIY BrewPi, why do you need a RaspberryPi and Arduino -- shouldn't the Arduino be able to act as a web server?
  • Can I hook up a Netduino and have it do all the monitoring/controlling along with acting as web server? (I know C#/.NET)
  • Is using a BCS overkill?
  • What about other kinds, such as Brewtroller?

I'm thinking of starting small and using the controller to measure/control my fermentation temperature in order to understand things better. Then I want to upgrade my system to electric and have the controller regulate temperatures in the mash. Finally I would want it to control pumps/flow control. Can the BCS do this? Can Arduino/RPi?

Essentially, I'm looking for a controller FAQ and what it can do.


I setup a Raspberry Pi 3 running BrewPi connected to an Arduino that powers my mini fridge for controlling fermentation temperatures. So far so good: brewed a lager and two ales successfully, which is critical here in Southern California. The next step is a similar hardware setup for controlling mash and boil temperatures once I eventually build an electric system.

3 Answers 3


I have built a temperature regulation system for fermentation and a mash controller for my electric kettle using Arduino and Raspberry Pi. The Arduino controls the hardware while the Pi handles the web interface, logging, etc. The Pi queries the Arduino over a USB serial connection. There are two reasons for this:

  1. The PID software and other stuff I wrote for the Arduino used up most of its memory, and I'm not sure I would have been able to add the web interface there.
  2. I prefer to have the hardware control and internet connection separate. I don't want the temperature controller to have problems if the WiFi goes down. With separated functions the whole internet can crash and my Arduinos would keep on doing their job without even knowing.

Arduinos are very robust and use a dedicated operating system that is doing nothing else but running one program. A Raspberry Pi is a much more powerful system capable of doing multiple things, but that also introduces more possibilities for unwanted interactions and things to go wrong. I started with just an Arduino and later added the Raspberry Pi.

  • What's your opinion on BrewPi Spark? Does that replace the Arduino? What Arduino did you get? How long did it take to roll your own software? May 15, 2017 at 4:32
  • And did you use this? diybrewpi.wikia.com/wiki/DIYBrewPi_Wikia May 15, 2017 at 4:59
  • I don't know anything about the BrewPi, but if it uses a Raspberry Pi, then I stand by my comments above. I had a couple of Arduino Unos lying around, so I used them. I was developing the cooling system hardware and the software together over time, so the whole process took a couple of months.
    – GigaFemto
    May 15, 2017 at 15:56
  • I just looked at the BrewPi briefly. It looks similar to my setup overall, except that I use a thermoelectric module to regulate the temperature of a water bath for the carboy. I like that approach, and I like to build my own stuff so I will stick with it even if it is not perfect. The documentation (somewhat out of date) for my system is at swent.net/Brewing/Fermentation.htm#Temp_Regulator
    – GigaFemto
    May 15, 2017 at 16:02
  • I got a RP3, Arduino Uno, and related paraphernalia. So far I tested hooking up a temperature probe successfully, so I will go ahead and start with fermentation control using RP3/Arduino. May 21, 2017 at 23:25

Ultimately yes the whole brew process could be completely automated with available sensors and mechanical controls.

BrewPI allows inputs from switches and temp sensors and outputs for on/off relays all controlled by code.

Most use these types of controllers for logging and controlling fermentation temp. But I've seen systems that even do dough in, step mash, sparge and do adjunct and hop additions.

The biggest hurdle for an automated system is the mechanical side. Accuators that drop pre measured ingredients, liquid valves, and pumps are all pretty easy. But a paddle system for a mash is a different story.

To automate the complete process would take many many different temp sensors and mechanical Accuators to take a brew from raw ingredients to finished beer. Even then would still have a lot of hands on needs even with the best equipment. With the best of code it would still need a halt for brewer assistance for things like a stuck sparge, stuck fermentation, Diacetyl check, and fining.

  • Good stuff. Although I would mostly want my temperature and--later--the pumps being automated. Anything beyond that would be too complex for my system. Specifically, what are main differences between the most popular controllers? May 12, 2017 at 4:20
  • @memnoch.jones then a BrewPI or the like is probably overkill, you can get a basic digital temp controller with heat/cool relays for 15-20 dollars on eBay or Amazon. Most will use a deep freezer with a small heater, place the temp sensor in a mason jar of sterile water and seal it so the prob is in the middle of the jar. This gives great stable temp for fermenting multiple batches at once. If just a single batch put the prob in the fermenter with a themal well. May 13, 2017 at 19:52
  • But I do want to geek out and have it available on a website. I should add that I would want mash/RIMS/HERMS control at some point, too. May 15, 2017 at 1:31

Yes, you can use Arduinos/Netduino/Pis to do your control and make it accessible via a small web server.

But before you go this route of writing some small C# script/python/etc... to get it all running may I suggest you take a look at little PID temperature controllers like these(https://www.amazon.co.uk/dp/B00KYL3W32). They have an internal 230V relay, and you hook up the probe and relay, sanitise the probe and drop it in your vessel. They are really easy to set up and require no coding; which I always prefer.

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