On 2014-03-03 21:39, Polly Esther wrote:
> I was reading some Alton Brown and he has this to say about pre-heating
> the oven. IF you set the oven for a temp and it dings and tells you it
> has reached temp, it has. BUT when you open the oven door, much of that
> nice hot air will escape. IF you're baking something that must have the
> correct temp, you need to pre-heat for at least 20 minutes. That way,
> the oven's floor, walls, ceiling, back and assorted other parts will be
> heated enough to maintain temperature even after you open the oven door
> and insert the 'grand recipe'.
> Of course, some of you already know everything but it seemed to me
> that this might be helpful to those of you who are hoping to duplicate
> the perfect cornbread, pound cake or meringue like Moma used to make.


Some of us know more than some others. There are a number of factors.
There is a rush of hot air out of the oven when you open the door, or a
rush of cool air going in, but I don't understand the 20 minute thing.
The walls of the oven are steel and it is a pretty good conductor, and
the metal heats up as part of the preheating. When you open up the oven
door those hot walls help stabelize the heat.


Whether or not I preheat the oven depends on what I am cooking. If I am
baking or roasting potatoes or a roast I let them heat up with the oven.
I make sure to preheat when I am baking, and I usually time things so
that the oven is heating to cooking temp when the goodies are ready to
be baked.