Brewing your own beer at home is a very rewarding experience and can even save you money after you get past the initial investment in equipment. But that savings literally goes down the drain if you don’t drink the entire keg before it goes bad. Scales will help you keep track of how much beer is left in each of your kegs, so you can finish them before the beer gets skunky or stale. ItsGraGra has a tutorial that will walk you through how to make your own keg scales for your homebrewing setup.
There are products on the market designed to do exactly the same thing, but, as with just about everything else related to homebrewing, they can get quite expensive. This project, on the other hand, can be completed for very little money. You can easily monitor a handful of kegs using less than $30 worth of hardware. This design is based around load cells, which are sensors that output an electrical signal proportional to the force applied to them. In this case, that force is coming from the weight of the kegs and is correlated with how much beer is left inside. Load cells aren’t always accurate, but they should be good enough for this job.
To tackle this project, you’ll need four 50kg load cells for each of your kegs. Those will be monitored by a dev board. ItsGraGra used an Arduino Nano, but just about any board can be used — you’ll need more I/O pins than the Nano has available if you’re monitoring a lot kegs. A 2004 (20 characters wide, four characters high) LCD provides a readout of the measurements from the load cells. The load cells are placed between two boards to create a scale for each keg to rest on. Load cells do require calibration and need to be setup for your specific kegs. But ItsGraGra provides the Arduino code and instructions on how to set everything up. If you’re tired of guessing how much beer is left in your kegs, this is a project you should consider.