Large Cakes - advice please

I want to make a large cake, not a fruit cake but a recipe I use already for an almond sponge. I was going to hire a large cake tin and double/triple the recipe BUT it has just occured to me about the cooking time. Is it just a case of keep having a look to see if its done or is there some kind of rule of thumb when you use a different tin OR should I use a proper recipe for a large cake?. Any comments/experiences from you cake makers out there would be welcome. Thankyou

Oh lord. You need to think about quantities first. It's all to do with volume rather than size. So from what I can remember if you want to scale up a recipe for an 8 inch tin to a 10 inch it's actually one and half times the recipe. And for a 12 inch it's two and a half. But that's round tins not square. I think the calculations are the same for a square but the measurements are 7, 9 and 11. Gawd its a long time since I've done this. I used to make wedding cakes. But the way you work it out is to fill the tins with water and calculate it by volume. You'll need a calculator for that.

Scaling up the cooking times isn't so logical. Keep the temperature the same but protect the outside of the tin so the edges don't burn. Tie newspaper the same height as the tin around the sides. If you're scaling up an 8 to a 10 then I'd probably up the time by a third but be keeping my eyes peeled from the time the smaller one should be cooked.

Does that help any?! I'm 100% sure on the quantities on the round tins, 95% on the square tins and winging it a bit on the timings.

In terms of cooking times i think it really depends how deep the tins are and how much mixture u put in it, the deeper the cake the lower the temperature of the oven and longer u leave it in there . I would say best thing to do is have a practise and see how u go. Gd luck lol

Thank you Tinkerbell and Autumn. Whoa, I did not know it was so complicated (knew I should have listened more in maths class!) Well, the tin I have seen is a heart shape (I know!) but my OH is quite good at calculating volume etc so I will get my calculator out and have a play about. Watch this space.. .haha

I'm probably too late here but I've been thinking about cake baking. I would worry about cooking at a lower temperature. Cake making is all about balance and almost chemical reactions and it would worry me that you wouldn't get the right texture at a lower temperature. Or it may not rise.

Then just now I remembered making a heart shaped cake out of two cakes. One square and one round. Set the square on its end to make a diamond shape. Then cut the round cake in half and put one on the top edges. Then cut round a heart shaped template. Devilled if I can remember the sizes I used but the diameter of the round has to be same as the edge of the square.

Anyway that way you get a bugger cake but use smaller cake baking methods. )

If im baking a larger cake i will have the over temp around 160 degrees ( fan assisted oven) and they have always come out perfectly and even a standard size cake i normally bake at around 180 degrees.

My mum used to make celebration cakes for family and friends as a hobby... for the larger ones, she would make smaller squares and join them together. Once it's decorated, you can't tell.