Why does it take 10 minutes to pre-heat my oven to 225 or 410? It seems like it should take less time to reach 225. I have seen other ovens that take the same time to pre-heat no matter the temperature.
Or is the pre-heating timing just a lie? Is my oven reaching the selected temperatures at different times before the pre-heat cycles are over?
Don’t know about yours. On ours when you set a specific pre-heat temperature, the temperature readout shows you what temperature the oven is until the pre-set level is reached and then it chimes. It takes less time to reach a lower temperature.
That can’t be possible. If it took the same time to preheat to 350 as it does to preheat to 420, how did it get past 350 on the way?
While we’re on the topic… I never pre-heat. It seems like a waste of time unless you’re doing something sensitive like experimental baking or a souffle (which I never do). I just put the pizza into the cold oven and add a couple minutes onto the box’s listed baking time. Works like a charm.
It doesn’t matter much for heating frozen pizza or tater tots or casseroles or whatever, but it will royally eff up cookie recipes, among other things.
Anyway, to answer the OP, our oven does the same thing, where it shows you the exact same time to preheat no matter whether you set it at 350 or 450. I’ve actually double-checked it with an oven thermometer, and yeah, it lies.
The same way it wouldn’t stop at 420 if it were set for 500.
:rolleyes:
I believe that don’t ask’s point was, if it takes ten minutes to preheat to 350, and ten minutes to preheat to 420, you can ‘fool’ your oven by setting the temperature to 420 when you only need 350. Since it must pass 350 before getting to 420, that must take less time–after, say, eight minutes, you dial it back to 350 and pop in your casserole. Presto–you’ve saved two minutes. :dubious:
I assume it’s because the element (or whatever it’s called on gas ovens) only gets as hot as it needs to to reach the desired temperature in 10 minutes, rather than always heating at the same temperature and then shutting off. It would be more like the climate control in a car, rather than the one in a house.
I’d also guess that fancier ovens with precise electronic thermostats don’t need to do this, while a regular oven does.
Sometimes it doesn’t work - tonight my kid did the no pre-heat pizza thing, but the pizza was very small and thin and it sagged through the rack a bit and dripped all over and the bottom crust stuck to the rack. (It still reeks like burnt pizza in here.) When you put it into a hot oven, that doesn’t happen.
there are two good pizza devices.
a wire mesh (is coarse and looks like the mesh of some ventilation grates). it allows crust to crisp. you shouldn’t cut pizza on it. keeps pizza rigid.
a pizza stone, ceramic heavy circle. doesn’t crisp bottom. holds heat for a long time keeping pizza warm on table, also don’t put on surfaces that could be damaged by heat, use a couple hot pads underneath.
Sorry folks, but I’m just going to have to jump in here with a nitpick. You* heat* the oven. You don’t pre heat a damn thing. You might heat the oven prior to cooking, but you do not pre heat an oven any more than you pre board an airplane.*
*(with reverence and respect to the late George Carlin)
You don’t nitpick information any more than you apple-pick information. Your jump in with a correction. You nitpick the larvae of head lice.
Are you nitpicking my nitpick? 
From the dictionary:
Verb: nit’ pik
Be overly critical; criticize minor details
Sorry, but though George Carlin got a laugh with it, the English Language doesn’t give a damn what he thinks.
The OED shows this to be a legitimate term since 1862.
It may not be logical, but that’s absolutely irrelevant; many English words have lost any logic. “Preheat” is a perfectly good word, especially since it does indicate something different than just heating an oven – it’s heating the oven to a set temperature prior to using it, not just turning it on.
Remember: Carlin was a comedian, not an etymologist. He told jokes. One should not use jokes as a basis for telling people what to do.
You heat the oven previous to putting the food in. Thus you preheat the oven. The phrase refers to action taken prior to cooking, not the heating of the oven itself.
The thing is, if I preheat my oven before putting in a roast, when I open the oven to put the roast in all the hot air rushes out. The oven then takes more time to get back up to the set temperature. So I’m failing to see the point of preheating.
All of the conventional electric, thermostat-controlled ovens I’ve ever used took longer to heat to a higher temperature, because the dial just controls the temperature at which the thermostat will turn the heating elements off. The elements click on when the temperature drops a little below the target, then back off again when the correct temperature has been attained again.
In fact, on this type of electric oven, you can tell the current temperature of the oven during preheating by dialling back until you hear the thermostat click off.
The walls and other parts inside the oven will be heated up, allowing the target temperature to be regained much more quickly than from cold.
Preheating doesn’t usually matter too much for a roast, but it does matter a great deal when baking cakes or bread.
Ovens temperatures aren’t all that accurate. Most have a simple sensor, or thermocouple for gas ovens in a single spot in the oven. I’ve heard some older gas ovens don’t even have a thermocouple and the dial just controls the gas flow like typical propane grills. Even after pre-heating, an electric oven will tend to cycle the heating element on and off, so most of the time the oven is below or above the selected temperature.
Preheating is even less accurate because the oven overall hasn’t heated up and a lot of heat will be conducted away through the walls for a while. To compensate for this, some electric ovens may heat until reaching a higher temperature than set for, while others may simply use a timer to estimate the amount of time necessary. And then, assuming you intend to use the preheated oven to cook something, you have to open the door and release a lot of heat, and putting a large cold item in the oven will absorb a lot of heat. Cooks who need a hot oven for some particular purpose sometimes wait much longer than the preheat time for the oven, or set the oven to a higher temperature than needed, then reduce the heat after preheating.
So for the OP question, preheating isn’t a lie, it’s just misunderstood. The purpose is to get the oven hot, somewhere around the desired temperature. ‘Hot’ meaning the air temperature in the oven, along with the walls and racks. If you need a precise temperature, get an oven thermometer and let the oven heat until the thermometer reaches a steady temperature and stays that way for a while, I would let it go 5-10 minutes depending on the temperature. But I’ve also found in most cases I can cook with just 3 general temperatures, under 350 degrees to keep things from browning, 350 degrees, and over 400 degrees where things need to sear, brown quickly, or with baked potatos, just cook faster. I don’t do much baking, so I can’t really say if that might require more accurate temperatures.