dude u cant be for real ….yes bc you *need* to especially for certain food…its like heating a skillet before using it….. if not ur food will be all fuckd up and cook unevenly and i jus…t i cant…. i mean….. i used to work in a kitchen and am a waitress now and i… i cant believe ppl r reblogging this….unless they are 13 years old and have never cooked or baked before. 

Preheating is actually more efficient than not preheating, because Science. The more mass you have, the more slowly the temperature will change. So if you put your casserole or pizza in a cold oven and then turn it on, it will take longer to get to the right temperature than it would have for an empty oven, which means it will take longer to cook. With something like a tray of frozen macaroni and cheese, the elements may have to stay on the entire ½ hour-45 minutes the food is in, which is a huge waste of energy, and the food will take 20-30 minutes longer to cook because the oven hasn’t been hot enough for long enough, so what’s the point of not preheating?

For the most even cooking, preheat and then wait another 10-15 minutes for the actual mass of the oven to heat up - when the oven says it’s preheated that just means that the air inside it is up to temp, and when you open the door you’ll be losing 30°-50°f with the air that comes out. If you haven’t waited the extra 10 minutes or so it’ll take about that long for the oven to come back up to temperature, but if you have waited then the heat radiating from the mass of the oven will compensate for the lost heat pretty much right away.

For some food, you even preheat the pan or surface you’ll be using to put the food in the oven, like a pizza stone or bread stone. Next time you make corn bread, try this: turn the oven on, wait 5 or 10 minutes after it says it’s up to temperature, then start assembling your ingredients. If your recipe calls for oil or shortening, don’t put it in the batter - instead, put ¼ cup or so in a seasoned cast iron pan (but NOT if it’s butter! Use shortening or oil in the pan if your recipe calls for butter!) and put the pan in the oven while you make the batter. (If that takes you longer than 4 or 5 minutes, keep a close eye on the pan. It needs to be hot enough that the batter will sizzle, but don’t let it get hot enough to smoke!) Use pot holders, the pan is HOT!!! Pour the batter in the pan, put the pan in the oven, and start checking for doneness a minute or two before the minimum recipe time.

Now tell me whether or not there’s a point to preheating.

This is part of why we use our toaster oven* whenever physically possible**–since the mass is so much smaller, preheating takes so much less time…and I’m assuming that maintaining/re-attaining the proper temperature is faster, too, again, because of the smaller mass.

* Or the Presto Pizza Pizzazz–it’s a ridiculous lookin’ contraption, but, wow the things it can cook, it cooks really well and with absolutely no time or energy for preheating.

** There are some things, alas, that are simply too big to fit inside the toaster oven.

Toaster ovens are great - from preheat to crispy-melty leftover pizza in 10 minutes flat? Yes, please!
Yes, I’ve heard that about the Presto pizza cooker - I guess the radiant heat from the head makes up for the lack of mass and walls?
I’d love to see a lab somewhere do an efficiency comparison of these 3 ways of cooking. Large mass-large space vs small mass-small space vs only the food mass-only the food space.

I tried making pizza from scratch and cooking it on a pizza stone, but the whole “preheat the whole stone for at least a half hour” process with an electric stove is ridiculous for energy usage.  Now, I make a pizza from scratch and bake it on the Pizzazz every week, and the crust is wonderful after six minutes of the bottom element only plus another 12 of bottom and top elements together–about half the time it takes for the pizza stone to be preheated properly (plus no pizza peel learning curve to climb.)  Regular frozen pizzas (as well as other small precooked bakable frozen snack foods or spur-of-the-moment quesadillas) are on the Pizzazz for cooking time only, no preheating, and turn (pun not intended) out great.  Even if the elements use more energy during cooking, I imagine the overall energy usage is about the same, since they don’t need to be on for a preheating cycle–but, overall, there’s time saved, even over a toaster oven. (We realllllly like the Pizzazz *grin*) ((Note that my dream home just might have a nice wood fired pizza oven out back…))

are these actually 3 essays based on preheating