Bread-Bakers v105.n014.6

I'm surprised by Seth's assertion that there's very little radiant heat at 
the top of an oven. I would have thought that as long as the walls of the 
oven are thoroughly preheated, then all of them, including the oven 
ceiling, would radiate heat. (Any hot surface radiates heat, whether 
burning or not.)

FYI, a few years ago I had the pleasure of meeting Harold McGee, author of 
the food science book, "On Food and Cooking." I asked him of all three 
methods of heat transfer--convection, conduction, and radiation--which 
transfered more heat. He explained that that was actually a tricky 
question. The precise ratios change with some 5th-power formula (if I 
recall correctly...). But the key thing is that below the mid-300s 
(Fahrenheit) convection and conduction deliver a majority of the heat.

But above the mid-300s radiation takes the lead. This is interesting to me 
because that is just the range in which the Maillard reaction starts taking 
place. And all my bread baking temperatures are above this threshhold.

All in all, this is more confirmation that long pre-heats are vital for 
bread baking (unless you're using the cold start method, which I find is 
superior for my sandwich loaves--but then I only use 375 degrees for those 
bakes).

Allen