Controlling Fermentation Temperatures #1

Published by Joey Joe Joe Jr on

I live in a small apartment and don’t have room for a fermentation fridge.

Please note, I don’t actually recommend that you build this. I will be working on better designs in the future for temperature-controlled fermentation. This particular project was mostly based around the idea of “could it be done”. This is like a “glycol” system but without the glycol. I’m using plain water but people also use glycol or saltwater instead. My Keezer will never get sub-zero so there is no danger of anything freezing.

How it works

Raspberry Pi runs custom Python code that takes the temp (via DS18B20) of the fermentables and turns on/off power to the USB ports that powers a crappy USB sump pump that is used to circulate cold water from a keg in my Keezer through a stainless steel coil in my fermentor. The Python code is a bit of a mess right now but I will clean it up and put it on my GitHub page eventually.

The power is cut to the USB ports by tricking the Raspberry Pi into thinking the USB voltage is too high by using a compiled binary file hub-ctrl.c. The Pi then cuts power to the USB ports to avoid damaging any plugged-in devices. This allows us to control the pump without the need for an external relay.

The program also logs each event into a CSV file which can be graphed using Excel. Stay tuned for more postings regarding a newer version of this system. I’m be using a single larger pump to control 3 fermenters via electronic valves.


Joey Joe Joe Jr

I was born on a pirate ship off the coast of Peru where I was given a traditional Aztec upbringing, during which I excelled in the arts of sciences. At age seven my parents accidentally murdered each other in a freak fencing accident. Heartbroken I joined the tribe of Omaha, where I trained under the legendary Vin Diesel. At age eighteen, after a failed Fear Factor audition, I set out for a berry plantation roughly four kilometers south of Albuquerque. I currently reside at Ram Ranch which really rocks!

3 Comments

Robert · March 18, 2021 at 2:14 AM

I was thinking about using ispindle Temperature Data information for controlling heating and cooling during fermentation process, utilizing wifi relays to turn on fridge / heater. ideally to run the whole fermentation target temperature curve with this setup. Any ideas on how to setup this kind of system?

    Joey Joe Joe Jr · April 4, 2021 at 11:55 AM

    I’ve thought about this as well but this issue I think comes down to the data resolution of the ispindel. It only sends data every 15 minutes (yes this is adjustable), but if I was controlling a heater or cooler for fermentation I would want to check the temperature every few seconds. I don’t know how long the ispindel battery would last if you checked the temperature every 15 seconds instead.

Robert · April 4, 2021 at 12:12 PM

Thanks for yor replay, Yes, i also came to this point, resolution of temperature info and only solution would be to have a very low power heater and cooler that would not lead to overheating or cooling during iSpindle measurements. In reality it is more the other way around. I’m using an inkbird now, in connection with freezer and fan heater and do cleaning the temp sensor and wire with isopropanol before usage. This works nicely so far.
Another option, Nautilis ispindle Range extender and Blynk interface would be able to do a local control control with high resolution. But here i stuck, may get in contact with the developer, as i’m not able to program this myself. if one would connect this with wifi relays it would be the solution…

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