Why do you need to preheat your oven?
When teaching people to bake I often get asked “is it really that important to preheat your oven?” The simple answer is YES!
Preheating your oven and allowing it time to reach the correct temperature before you put anything in it is possibly the single most important thing you can do when you are baking. If you don’t preheat your oven the temperature won’t be hot enough and the end result may be a heavy, undercooked mess – obviously a great reason to turn on your oven as early as possible!
Good recipes will ask you to preheat your oven before you actually start any of the preparation and remember that the average oven will take at least 20 minutes to heat to the correct temperature so make sure you allow time for this.
Once the temperature you want is reached, the oven will let you know, usually by turning off its thermostat light. I always recommend, if you have the time, to let the oven ‘settle’ into this temperature for 10 minutes or so before you actually bake anything. The reason for this is that that ovens take a little while to ‘settle’ into a temperature and they run through cycles of slightly higher and slightly lower temperatures, with the indicated temperature as the average. The longer an oven is preheated the smaller these fluctuations become. It won’t make a huge difference to your baking but it will mean that the temperature is more accurate.