I made a dish tonight in an enameled cast iron vessel, and it caused me to wonder...
The dish was simple roast potatoes, as revealed/recreated by Cooks Illustrated (Nov/Dec 2009), wherein the method involves a short parboil followed by vigorous and prolonged roughing up, before being scattered on an oiled, preheated (450F) rimmed sheet. Instead of the sheet, I used a large, shallow, rectangular LeCreuset roaster (thinking it would retain heat well). I chose CI frankly out of worry that my tinned copper would be flirting with the magic 437F melting temp of tin.
The recipe calls for rotating the pan several times, and for removing from the oven to flip the potato slices when browned . If one follows the recipe literally, the oven is opened at least twice before finish (more if one rotates and checks).
Now, here's the wonder... The spuds turned out just fine, but I'm wondering, since copper's conductivity is dramatically superior to CI, AND the specific heat (heat holding capacity) is better by weight, wouldn't very thick copper both: (a) hold the heat better when dehors the oven; and (b) more quickly regain the heat when put back in?
This may *sound* like a theoretical matter, because copper is most often touted for its responsiveness on the *stovetop*, not in the oven. But thin, service-grade copper is not going to have the thermally inertial mass to hold the heat during the two out-of-oven intervals this dish requires. Now I'm wondering whether 3-4mm copper would have done a better job both in *holding* the heat and *coming back* to heat.
I'm thinking the thoughtful thinking on this subject is not finished. Thoughts invited.