Pre-heating v. Cold oven

[the_nomad]

Apologies if this is a really obvious question (new member!) but I can't seem to find the answer covered anywhere, including the EGullet fora, Harold McGee, et al.

Just about every recipe involving an oven seems to recommend pre-heating the oven to a specific temperature before putting the pastry, bread, meat or whatever in it. Now, obviously there's a good reason for that in that starting at a preset temperature makes it easier to predict cooking times, but other than that is there any reason not to start cooking in the oven from cold? I've heard something about starting at set temperatures being very important for bread, for example, but haven't been able to track down any more details.

Any information would be very gratefully received!

(Although this is the baking forum, obviously, I'd also be very interested to hear about the effects of pre-heating the oven on roasts, vegetable and meat alike.)

Thanks in advance!

[etalanian]

Hi,

There are differing opinions on this, but I think unless the recipe specifically states that the oven should be cold at the start, it's safest to preheat.

Eileen

[Fat Guy]

Certainly with bread, the "oven spring" is an important early baking stage. This requires a pre-heated oven.

And given that every oven heats at a different rate, starting cold would produce a lot of variation.

[alanamoana]

the necessity of preheating your applies to the chemical and physical changes that take place within your product when it is placed in the oven:

1. fats melt

2. gases form and expand

3. sugar dissolves

4. microorganisms die (yeast)

5. proteins coagulate

6. starches gelatinize

7. gases evaporate

8. caramelization or maillard browning occurs

9. enzymes are inactivated

etc.

edited to add: all of these processes take place at a specific temperature. if it takes too long to get to that temperature, problems arise. of course, you can start at too high of a temperature as well. baking is really the ability to control oven temperature to get the desired result from your product.

with very few exceptions (i think there's a recipe in recipeGullet for a cold oven pound cake), if you start your oven from cold, the process takes too long and you end up with an inferior product.

example: meringue - you spend time whipping a meringue, carefully adding sugar and creating a stable foam. if you want to end up with a crisp light product but start off with a cold oven, the foam breaks down before the proteins surrounding the air bubbles can coagulate. the bubble breaks, the gases escape and the foam deflates. you end up with a dense cracker instead of the nice light meringue you were looking for

example: puff pastry - time spend rolling butter into dough to create hundreds of layers. when placed in a hot oven, the butter melts, the moisture turns to steam which expands and separates the layers of dough. the proteins in the dough coagulate and set which results in a light flaky and crisp pastry. if you start in a cold oven, the butter will melt out without allowing the moisture to turn to steam. the proteins not being able to coagulate, will stick together and you'll end up with a greasy mass of grossness.

i could go on and on. i think some of these processes are easily translated to meat and vegetable cookery as well.

edited to add: a good book to read about all of this is "How Baking Works - Exploring the Fundamentals of Baking Science" by Paula Figoni

Edited May 28, 2008 by alanamoana (log)

[sanrensho]

Certainly with bread, the "oven spring" is an important early baking stage. This requires a pre-heated oven.

Actually, you can get excellent oven spring from the "cold oven" method. I've tried it and it works. And others have reported the same.

There's a very good thread on the cold oven method on Dan Lepard's site:

http://www.danlepard.com/forum/viewtopic.p...ff15242e1680f4d

[Chris Hennes]

i could go on and on.  i think some of these processes are easily translated to meat and vegetable cookery as well.

←

I'm not so sure about that: take a roast, for instance. Provided you are not doing an oven-sear on it (i.e. you are not starting at 500 F and dropping it down, perhaps because you seared it on the stovetop first), I don't see how pre-heating the oven has any real effect. I can't think of a reason not to, at least preheat while you are searing, but if the oven isn't full-heat before the roast goes in, so what?

[Fat Guy]

Certainly with bread, the "oven spring" is an important early baking stage. This requires a pre-heated oven.

Actually, you can get excellent oven spring from the "cold oven" method. I've tried it and it works. And others have reported the same.

There's a very good thread on the cold oven method on Dan Lepard's site:

http://www.danlepard.com/forum/viewtopic.p...ff15242e1680f4d

←

Very interesting. I guess there's a whole world of cold-oven experimentation to be done. We probably can't rely on professionals to do it, though, because they're nearly always working with ovens that are on all day.

[the_nomad]

Wow! Thanks for all these fantastic responses already - this is stunningly useful.

I'm particularly interested in the science of *why* things work here (I'll confess, one of the reasons I'm looking into this is as background for a cooking show episode, although I'm also interested for my own cooking), as well as what - thanks for all the tips already.

alanamoana - thanks for the book tip. I couldn't find a specific baking book that dealt with the science - that's really helpful, and has been added to my to-buy list! (If you fancy "going on and on" any more, I'd be very interested to read it.)

Re roasts - with the possible exception of time sitting around below pasturisation temperatures (60ish Centigrade), which would take a *really* slow oven to have any effect, I couldn't really think of many ways in which food could be ruined by taking longer to pass through a temperature band, which is presumably what you're going to get starting from a cold oven. Certainly I've started sous-vide meat when my water bath was still a few degrees below even temperature without dreadful results, although of course that might have just been luck. Anyone shed any light on that?

Edited May 28, 2008 by the_nomad (log)

[Kerry Beal]

Of course - back in the days before convection ovens, if you didn't preheat the oven, then the elements on the bottom and top of the oven heating up would burn the bottom or top of the items you were baking.

I still preheat for most items, unless I'm just heating something up in the convection, mostly so I can predict the length of baking time.