Explaining this just to make sure I get it.<p>When we cook we're bringing up food to a certain temp, then maintaining it at that temp till it's done cooking. If we could perfectly insulate it, then it could hold that temp as long as we want without being on the fire. So the only energy input is getting it hot -- after that it's cooking on its own.<p>So this is trying to approximate that by insulating the pot.<p>I always sort of assumed that there's a lot of heat 'loss' from food itself heating up -- as in most the cook time is getting the food up to the temp (i.e. when cooking a steak), not waiting for it to cook at the temp. But I suppose that for certain grains and stews and things that thinking is wrong.