preheat oven or not

[dustypuss]

Dose it really matter if you preheat a oven or can you put the food in straight away and just cook it for 5min longer?

[Jugglering]

It does make a difference to some foods (like bread) but not to others (the heat is required to give a good crust). I generally preheat the oven if the recipe calls for it, simply so that I know how long to cook it for, otherwise I am guessing. I think it takes more than 5 minutes for an ordinary oven to reach say 200 deg C though - more like 15 minutes or so. I would definitely use a preheated oven for frozen ready meals as they have been tested for timings using a preheated oven.

[dustypuss]

I'm just about to have a pizza . and yes I did preheat the oven! thank you

[Mamjet]

good question. usually i cant be bothered waiting for the oven to preheat and whack it up to full for as long as I can wait. I doubt Delia would agree though.

[WoWo]

As said it does depend on what you are cooking, for your average ready meal I'd just stick it in and as you say give it another 5 mins.

[ethandron]

i think it's more critical for things like baking cakes or souffles. there is a 'physics' reason behind it, but i'm afraid i'm no good at physics so can't explain it.

[hedgehogy]

Yes, by not pre heating the oven, frozen food espescially has more time in there at the warm rather than hot stage, hence more likely for food bacteria to multiply and give you tummy troubles

[dustypuss]

I wonder if i should post the question i science ? In fact I will !