Oven preheating means that before baking any food, the oven needs to be preheated to a specified temperature in order to meet the baking time in the recipe.

Before baking the food, the food is at room temperature, and the general temperature when baking is required to be in more than one hundred degrees or even two hundred degrees, if you do not preheat, directly put the food into the oven, it is tantamount to slowly heating the food from the room temperature state to the set temperature.

If you preheat the oven, the food will go from room temperature directly to the set baking temperature, and these two practices will obviously have different effects on the internal organization of the food when it is baked. For example, if a cake is baked without preheating, it will not be as fluffy as a cake that has undergone the preheating process.

Expanded:

Other notes on using the oven:

1, baking height

Baking with a small oven is basically just a matter of putting the food in, but a medium-sized oven usually contains three heights to choose from: upper, middle and lower. As long as the recipe doesn't specifically state the upper and lower heat temperatures, placing the baking sheet on the middle level is sufficient.

If the upper temperature is high and the lower temperature is low, unless the oven's upper and lower temperatures can be adjusted independently, it is usually better to add the upper and lower temperatures and divide by two, and then place the baking sheet on the upper level, but keep an eye on the surface to see if it is overcooked.

2, food overcooked

Medium-sized ovens have enough space and temperature control, so unless the oven temperature is too high, too close to the upper flame or too long, it's less likely to be scorched.

Taking the production of Chinese and Western snacks as an example, because the temperature of a medium-sized oven is not as stable as a professional large oven, we have to pay more attention to the changes in the oven temperature when baking, and we have to change the side of the snacks to turn the head or lower the temperature in order to avoid the cake or the bread expanding unevenly on both sides, or the cookies are overcooked and undercooked, and other situations occur.

Baidu Encyclopedia - Oven Preheating

Baidu Encyclopedia - Oven

This is the first time I've seen an oven preheating.