This man turned thermostats into a $3 billion business. Can he do the same for food waste?

Inside a gadget-filled lab at an office outside San Francisco, there’s a refrigerator packed with clear Ziploc bags of rotting food. It’s an extreme version of the experience almost everybody’s had of opening their fridge to discover mold forming on a very leftover meal or a bag of spinach that’s turned into black goo. The bags are there for testing purposes—they represent the typical food scraps an average household produces on a regular basis. Mill Industries, the company that owns the...