First, a single-stage unit is focused only on cooling and does not connect to a heat source to raise the temperature when necessary. This means when it's set to, say 55 degrees, the actual temperature in the freezer can fluctuate within a range of as much as 5-7 degrees depending on its compressor and other factors. There is also no way to automate a fermentation schedule which is important when brewing certain styles and is also a great way make sure your beers finish where you want them to.
You've seen our fermentation chambers that accomplish these goals but I'll be the first to admit that most homebrewers will not go through the trouble I did. Enter Caleb's Fermostat! With its intuitive interface and design, it takes the old style johnson controller to a whole new level!
If he can get the support he needs through kickstarter, it could easily be the next great gadget for the serious homebrewer! Check out his funny video below and if you like what you see, head over to his kickstarter page to read more.