The water bath's double-walled, so that power consumption isn't heinous. We're looking at nonofficial steady-state heat losses/gains of 15-30 Watt at the most common temperatures.
I do have a suggestion on the thermodynamically disfavored process of changing the water temperature rapidly though. Could you simply hook up one or two other reservoirs? Drain the 'cold' tank to one of those, preheat the other, then pump the other in and suddenly you're cooking.
Or just accept hot/cold faucets with a once-through system for rapid changeovers, followed by precision temp control on recirculation.
You also have to do it very quickly due to anaerobic pathogens like Clostridium botulinum and Listeria monocytogenes. I don't think it's possible for something that fits comfortably in a kitchen and runs on a 120v line.
Too true! The most we can do is auto-retrograde starches and cool baths that are cooking at 60C upwards down to 54C to a sort of "holding temperature". Very fun to play with.
That's kind of neat that you can drop it down to a lower holding temp. I hadn't thought of that. I'd be curious to hear how different foods hold up in that case.
That may be the case for some theoretical level of foodborne pathogen... but in reality we're all leaving our chinese food / pizza out until it gets cold on the counter, then putting it into the fridge and eating it a few days later for lunch. We're dumping hot soups into containers and putting them in the fridge. We're eating anything that doesn't have mold on it regardless of the sell-by-date. Cooking, I think I've managed to genuinely give myself food poisoning only once, trying to refrigerate a gallon and a half of chicken noodle soup. This happens far more often with takeout, an accepted cultural institution.
If the water can be rapidly adjusted in temperature (through a cold water hookup or otherwise), this represents a major safety improvement in the production of the 'leftovers' genre of our cuisine over the status quo, as well as the few dishes we have that are cooked and eaten cold.
What if you flushed the container with cold water? Seems easy enough to rig it to a cold water line and have a hose going into the sink to dump the hot water.
I don't think cold water out of a tap is cold enough. I don't know the exact times, but it's generally recommended to use enough ice in ice water that it won't totally melt before the food gets below 40F. But you could do some sort of chilled reservoir. Then you're doubling the size though.
I figured it wasn't cold enough. The idea would be to dump the latent heat in the water. So at least you start from room temperature water and chill it from there. I'm guessing this still wouldn't get cold fast enough, but I don't know how fast "fast enough" is.
This is really easy to experiment with. Hard boil a few eggs (using convetional boiling water in a pan) and then see how quickly you can cool that egg.
The thin clear container and large volume of water is going to be a bit rough on power consumption for that use-case though.