Cooks: Preheat vs. start in a cold oven. When? Why?

Some recipes for cooking in the oven (okay, the vast majority) tell me to preheat my oven before putting the food in; but some (Alton’s recipe for roasted bacon, for instance) call for putting the food into a cold oven and then firing it up.

What’s the rationale for this? What would happen if, say, I put my batter-filled cake pans into a cold oven and then started it going to 350?

Just talking off the top of my head here, but I thought that in baking, at least, if you are depending on steam to help with the rise of the batter, you need to start off with a hot oven. You get a good blast of heat to start off with. But again, that’s just something i’ve heard.

I think that for most foods an average American would eat at night, pre-heating doesn’t make much of a difference. For others, say breads and pastries, it will make a difference and should be done.

On the other hand people and cookbooks tend to tell you to cook for a certain length of time rather than a better measure of doneness, like temperature. It’s bad enough to say “cook the meat in a 325 degree oven for 30 minutes” rather than “until its temperature is 165”. If you don`t even start with a 325 degree oven you’re even less likely to get it right.

Plus, while it might not matter for some foods, ovens vary widely and some may heat up much faster.

I can’t think of a good reason to start with a cold oven, actually. Can anyone?

My oven repair man once explained this to me. As he explained it, if a steady temperature is really important (like with most baking), then you want to preheat the over for at least 15 minutes. He explained that when an oven first heats up, it tends to over heat and then drop down and reheat (oscillating) until the temperature evens out, due to the way that the thermostat works. It takes that amount of time for the heat to even out enough for the temperature to stay pretty constant.

This is based completely on what he said, so take it FWIW.