Clever poor vide unit you have there Queball! Your innovation has me wondering if you can use an old analog hot plate or crock pot and a PID (like an auber) to control water temperature.
Oh! PZ .... I wish I had your knowledge ..... Thou art way, way above my pay grade! "Old analog with a PID(like an auber) ..... Sounds great .... really?
You are way too kind Queball - the reverse is actually quite true - I wish I had YOUR experience in cooking. I can do a few things alright, but your skills are way above MY pay grade
By "analog" I mean the old manual dial kind; the cheapest ones without a digital display. The Auber PID is a stand alone unit that does the same thing as the ones built into many good pellet cookers. Mine has two probes, one for general temperature and another for the food. After your post I was thinking that one could dip the temperature probe into the water, which would allow the Auber to control the power to the crock pot (you plug the crock pot into the Auber, crank the pot to full temperature, and the Auber will vary the current delivered to the crock pot.
However, as bregent mentioned, without a water circulator (built into good sous vide machines), you can get hot spots and cold spots in the water bath when the food bag is large, which leads to uneven cooking.