I started another thread specific to the cookbook I was reading (Michel Roux's "Eggs"), however I figured I start one more specifically about spong cakes.
The book I was reading says to beat 4 medium sized eggs with a bit more than a half cup of fine sugar. It then said to whisk for 12 minutes until the mixture left a ribbon trail when lifting the whisk out of the bowl.
Well I whisked for 30 minutes and while eventually I got a small thin ribbon, it did not appear to be nearly as thick as the 1" trail in the photo of the cookbook.
So my question to experts of sponge cake, how thick should the eggs/sugar be before folding in the flour?
Many thanks.
MrYummy
Bad luck on your first attempt at a Genoise.
There is quite a distinct difference between a traditional separated sponge batter, and a genoise (genoese) batter. The genoise is often called a fortified sponge, as it has the addition of melted butter to the batter, and will have a richer finished flavour, along with a couple of additional days shelf life due to the additional fat (moisture) from the butter.
When beating your eggs and sugar to make a genoise, firstly make sure you are using room temperature everything - eggs, bowl, whisk.
Second, make sure you use only a stainless steel, glass or copper bowl, as plastic has an unpleasant ability to traps fats and detergents, both of which will interfere with an eggs ability to incoropate air sucessfully. A plastic bowl is the kiss of death to egg whites for meringues etc, so investment in a large 10qt stainless steel bowl (if you are using a hand-held mixer) is a worthy investment.
Third, even though you are using whole eggs and it is not so paramount, if I have used my SS bowl for chocolate or cookies prior to making a genoise, I wipe it and the beater down with white vinegar and paper towels to strip any lingering fats. (This step is mandatory for egg whites) It's just a little added protection that never hurts.
I normally start a genoise batter off by loosely beating the eggs on low speed to break up the whites and incorate the yolks well for a minute or so before I add any sugar.
Once the eggs are well foamy, I add the sugar (I use a KA stand mixer) in a slow steady stream down the side of the bowl, wait til all the sugar is wet, then raise the speed to a high medium and leave well alone for 3 - 4 minutes. By this time, the eggs will have quadrupled in volume, be a very pale creamy shade of yellow (almost the colour of butter) and have the pouring consistency of a light custard. When you lift the whisk from the bowl, the "ribbon effect" will be quite evident in its meaning, as the stream of egg from the bottom of the whisk will not immediately blend back into the mixture remaining in the bowl - it will rest on top, and have a ribbon-like appearance.
It is at this point that you add your sifted dry ingredients, and then your butter. Pour immediately into pans. I bake my genoise at 165 deg C fan-forced.
One other thing to remember is that the fresher the eggs you use, the better, too!
Good luck with your next attempt!