This comes up a lot and I'm not certain about this small of a batch but you might not need one. The reason being is you will want it running at full power at all time. You will want full power to Strike and full power to start and keep boiling. I suppose if you must recirculate my PID came from Jager bush and he makes some of the cheapest best controllers out there. Side note you can make one but if you do I would recommend making a small mobile one. That brau supply is nice too. Auber inst. Makes a good cheap one too, and they are the people who makes all the parts people use