I did this batch of genoise with 3 eggs, though it expands up pretty well, and tends to cook quite quickly, as it's so light. The batch size will make 12 muffin-size cupcakes, a swiss roll tin, or a 23cm sandwich tin (though I normally use 4 for a sandwich sponge, as a like a bit more depth to a large cake). I also added lemon zest...genoise works really well with fruit flavours (I finished the cupcakes off by simply dunking them in a lemon water-icing).
For a foam-based cake, don't use vanilla pod seeds...if you add them to the egg mixture the small seeds really retard the foaming (I assume they puncture the air bubbles as they form). I would definitely recommend using a stand mixer or hand whisk, working the egg mixture takes a good 5-8 minutes, even with the assistance given by the cream of tartar.
Genoise Sponge - Recipe
Pre-heat oven to 200'C
Ingredients
- 3 large eggs
- 50g caster sugar
- ½tsp crean of tartar
- 75g self-raising flour
- 60g butter
- (optional) Zest from 2 lemons
- (optional) 1tsp vanilla essence
2) Place the butterin the microwave for ~30 seconds, until it is about half melted...stire it until it is fully melted, then put it to one side.3) Place the sugar and eggs in a stand mixer bowl with the whisk attachment
4) Start to whisk the eggs and sugar. Once it has begun to foam, add the cream of tartar5) Continue to whisk the mixture until it reaches the ribbon stage. This is when, as you bring the whisk out, a trail of the mixture is pulled out, and when it falls it leaves an impression on the surface. If it's too slack, the air will come out when you fold in the dry ingredients...if it's too stiff, the final cake will be dry.
6) Once the ribbon stage is reached, sieve in the flour onto the surface of the mixture. If you are using the lemon zest, add this in now as well.7) Very carefully fold the flour into the egg mixture, trying to remove as little air as possible. I think everyone has their own specific technique...I tend to do a big, slow scoop round the outside, lifting the mixture over the top, and then cut through with the sharp of a thin plastic spatula. Things you'll often hear advised are to use a metal spoon, however what you are looking for is a thin edge, so you cut the mixture, rather than breaking the air bubbles. You need to delicately hunt for dry pockets of flour in the mixture, foten hiding down near the bottom.
8) Once you have folded in the flour, take the melted, cooled butter (it should still be liquid), and pour it round the outside of the mixture.9) Carefully fold this in as well. You'll need to hunt down towards the bottom, and again lift and fold it into the top of the mixture.
10) Once all this is done you should have a smooth, light and slightly glossy mixture. You can now pour or spoon it into your cake tins (be careful not to bang the tin, or crush the air out now...you've just spent ages keeping it all in). Lightly grease the tins with a little butter, spreading it with your
fingers to get a thin layer, especially round the base of the tin.11) Genoise bakes very quickly. For a swiss roll sheet, it will take about 6 minutes...maybe 6-7 for muffin tins. Large cakes will take slightly longer to cool the middle, so maybe drop the temperature down a little to make sure you do not burn the middle.
12) Once they are removed from the oven, take care with them until they are cool, as they are delicate cakes...far more delicate than a butter-based sponge. Cool them on a wire rack, and then decorate (whipped cream and fruit is a great match)