A sensor to monitor beer fermentation progress
In addition to a camera monitoring the airlock in the fridge, I have used a pressure sensor for two years now to see how things are going. The sensor (MPX5010DP) is meant for low pressures, and cannot be used in a closed and pressurized vessel.
Parts I have used, are:
- 1x MPX5010DP. 0.2-4.7V output measures 0-10kPa
- 1x ADS1115 A/D converter
- 1x 4x 5V/3V3 Voltage Level Converter
- 1x Wemos D1 mini
- Filter cap's for MPX5010: 1x1uF, 1x10nF and 1x470pF
- Arduino connection cables
- 5mm ID Silicone hose connected to Positive Pressure on the MPX5010
- 1x Box. My favourite for such projects is a 82x57x32mm. If you are situated in Norway or Sweden, it is available at Kjell&Co (#89043). The box is also found as Velleman #G1019 or CamdenBoss #400-019.
The schematic (fermpress-sensor-d1.pdf) should be self-explanatory in how to connect the parts.
ESPEasy is used as firmware on the D1 mini.
I created two devices: One collecting raw data from the ADS1115 every 2s and Gain set to 2/3x. The second one is a Dummy Device collecting average data from every 10th measurement every 15s via Rules (beer-ferm-rules1.txt).
Measurements are sent to Home Assistant via MQTT.
This is how it could look like in the beginning of a (lager) brew:
The only Formula I have used, is "%value%-1200" for the raw device, just for getting numbers down to more human levels. The interesting part is the curve itself.
This is how it looked like at the end of the same brew. There was still pressure in the fermentor 3-4 days after the last visible "plop". At 19:00, fermentation has definitely finished:
This is how it looks like inside the box:
The box is placed as high up above the fermentor as possible (MPX5010 does not like humidity):
The other end of the hose ends up in a T with quick disconnects on top of the fermentor:
Being bored of cleaning up the mess of fermenting virile beers, I use a blow-off tube ending up in a 3L Erlenmeyer:
