Don't know about fermentation, but I think I will be ordering one to replace the mechanical thermostat that controls my garage's evaporative cooler. The dead-band is about 20F and all too often it gets stuck on and the cooler runs all night.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk