I just got one of those new fancy stainless steel thermoses recently to keep my morning coffee piping hot for hours, and I started thinking... The reason many coffee stops put their coffee into thermoses is that keeping it on the burner burns out the taste after a while (like 7-11). My guess is that taking it off the burner and putting it into the thermos prevents the coffee from over-cooking. However, arguably, if you brewed a pot of coffee at 170 degrees and poured it into a "perfect thermos" where there was no heat loss, then wouldn't the coffee continue to "cook" at that 170 degrees? Why is that any different than keeping the pot of coffee on the burner and maintaining its temperature at 170 degrees? The salient difference is that, on the burner heat has to be continually added to the system to compensate for the dissipative effects of heat loss from the top of the coffee pot due to the lower ambient temperature in the room, whereas this is not the case in the perfect thermos. However, as far as molecular interactions, the average kinetic energy between the coffee molecules would appear to be similar between the two, and isn't this what "cooking" is? So why does one continue to cook and the other not? Or are they both cooking in a different way, other than just the anisotropy of the burner case heating unevenly from the bottom?. Or is it just the fact that, say, water burns off the top of the 7-11 coffee and leaves the system that accounts for the different effects? As another example, say you are cooking 2 roasts and get the internal temperature on both up to 350 degrees to the point where they are both nice and juicy. Now, you leave one in the oven at 350 degrees and you take the other out and put it into a perfect thermos. You leave both roasts in this state for the next 12 hours. What do you have now? We can bet that the roast that stayed in the oven is going to be burned to a crisp. But what about the roast in the perfect thermos? Ostensibly, its internal temperature has stayed at 350 degrees the entire time just as the roast in the oven. So hasn't it "cooked" just as much as the roast in the oven? What is the difference and why?