I would like to use the arduino to monitor and create the best beer. I've look up some info and the best way to look for quality is to measure the beer density. I could not find any digital Hydrometer that I could plug to my arduino. Are there any other ways to monitor the brewing process?
I am planning to use my arduino to control my brewing process. Eventually also to log fermentation temperatures. I didn't realize an electric hydrometer was possible. I plan to look into it.
Right now I am only controlling my mash heating for my HERMS. Eventually I will be able to monitor temperatures with multiple probes simultaneously, Adding data logging, and other features. I will share more details once I get all the kinks worked out.
In my opinion you absolutely do not need any kind of electronic controls to make good beer. Sanitation, happy yeast, and the brewing process are what make good beer. I just happen to enjoy tinkering with electronics, and one day they may allow me to be lazier on brew days.
I've not seen any inexpensive density sensors either, which is surprising since they can be made from mass-produced components - a PZT actuator and a quartz tuning fork. The sensor works by producing a vibration and then measuring the resonance in the tuning fork to that vibration. The density of the liquid has a predictable affect on the resonant frequency, i.e. the point with the highest resonance, and so from measuring the resonant frequency the density of the liquid can be determined.
The paper here describes how to build such a sensor, and how it peforms. If you search for the title, you can also find the full text.