This is the one DIY project every home brewer needs to tackle. It's not a stir plate, a copper IC or a paint can fermentation heater. It's MUCH more critical to brewing award-winning beer!
Of course, I made mine out of stainless, with tri-clover fittings and an arduino controller.
Of course, I made mine out of stainless, with tri-clover fittings and an arduino controller.