As the specific gravity of the fermenting beer changes over the fermentation process the buoyancy of the weighted cylinder will change the angle that it rests at. This will be detected by the accelerometer/gyroscope module. This will be read by the esp8266 calculated the sg based on the angle and transmitted over WiFi computer network to a local or cloud based log.

To Do:

Find a battery with proper dimensions and capacity
Find power supply module
Figure out how to correlate measured angle to specific gravity
Write software to run the device
Write software for device to talk to (although it may be possible for the device to directly write to a google doc or other cloud based service)
Testing and refinement