Updated: Nov 5, 2022
FUNDAMENTALS OF A GENOISE SPONGE
Genoise Sponge is an Italian sponge that has a light an airy texture that are used in many applications often layered cakes filled with creams. The common make up of the sponge are sugar, eggs, flour and butter.
When preparing Genoise sponge, the key to success is to follow a few simple steps as lined out below:
1. Heat eggs to between 40 - 45˚C before aerating.
The only thing that keeps genoise sponge so light and airy is the aeration of egg foams. When making this sponge, it is crucial to gently heat the eggs with sugar to between 40 - 45˚C. At this temperatures, eggs has the ability to foam and create air pockets at its full capacity. A cold egg on the contrary will not be able to foam as well and if heated too high in temperature, you can end up with scrambled egg. So the idea is to gently warm the eggs.
The addition of sugar in the eggs during the warming process also helps to slow down the coagulation of the eggs, which prevents the eggs from scrambling too easily and too quickly. You can however, add in the sugar after the eggs have been warmed, but be very careful to watch over the eggs.
Sugar in genoise sponge are relatively high as it functions to trap moisture in the sponge giving you a soft and light crumb.
2. Figure '8' test for your egg foam mixture
When you have never made Genoise sponge before, one of the challenges you may find is to know when the egg foam is actually ready before you can fold in the sifted dry ingredients.
One of the best and very traditional way to test if your egg foam is ready is to do the figure '8' test, also a stage where the egg foam has reached a 'ribbon stage', where you pick up some of the mixture with the tip of your whisk and try to draw the figure '8'. If the figure '8' stays on the surface of the foam mixture without disappearing too quickly, you have incorporated enough foam in the mixture and it is ready to fold in the dry ingredients. If the figure '8' disappear as soon as you finish creating it, you will need to whisk the egg foam further more.
3. Ensure that the melted butter is cooled before incorporating into the batter
During the process of folding all the ingredients together when making Genoise Sponge, melted butter are added in with some of the batter to make it to a consistency that is similar to the foam mixture itself. This butter mixture is also called the 'sacrificial' batter as you sacrificed some of your egg foams. The purpose of doing this step is to prevent the melted butter from falling all the way to the bottom of the bowl when you try to incorporate it into the batter.
Ensure that the melted butter is cooled before doing the above step as hot butter can melt the whole foam in the batter, causing it to collapse and in turn result in a dense and rubbery sponge. So, as long as the melted butter is cool to touch, it is ready for incorporation.
4. Fold in the sifted dry ingredients slowly and gently
Just remember that the Genoise egg mixture consist of nothing else but air, and of course some fat and sugar that stabilises the foam. The tips to maintaining the foams that you have worked so hard on developing in the first stage is to sift in the dry ingredients a little at a time and gently fold them into the egg foam mixture. Ensure to turn the spatula when folding and really turning the batter over and ensuring no dry ingredients are clumping up at the base of the bowl.
5. Sift the dry ingredients into the egg foam, not dumping them in!
When incorporating the dry ingredients, it is important to sift them on top of the egg foam. This is so that they are gentle on the foam. If you dump the whole dry ingredients on top, this will just collapse all the air in the mixture.
Yield : 1 x 16 cm sponge
Equipment: 16 cm diameter x 3.5 cm height cake ring
160 g Eggs
90 g Caster Sugar
10 g Honey
60 g Cake Flour or Plain Flour
20 g Corn Flour
15 g Cocoa Powder
30 g Unsalted Butter - melted and cooled
1. Melt the butter and leave at room temperature to cool slightly.
2. Sift flour, corn flour and cocoa powder together and set aside with the sift ready to use.
3. Place a pot with water and bring to a simmer over the stove. In a bowl that sits well on top of the pot, place the eggs and whisk in the caster sugar and honey. Place the bowl over the simmering water (bain marie) and continue to whisk the egg mixture until it reaches 45˚C.
4. Once the egg mixture reaches 45˚C, transfer into a stand mixer bowl fitted with a whisk and whisk over high speed until light and airy. To know if it is ready, you should be able to draw an '8' figure with the mixture from the tip of the whisk and the '8' will hold on top of the foam mixture without disappearing too quickly.
5. Sift in half of the sifted dry ingredients into the foam mixture and gently fold through, place 2- 3 tablespoon of the foam mixture into the cooled melted butter and gently fold so that it resembles the foam mix. Pour the butter mix into the foam mix and gently fold then followed by sifting in the last half of the dry ingredients.
Be very careful not to over fold or mix during this process as this can deflate all the lovely air that you have created.
6. Pour the genoise mixture into the prepared baking tin and bake in the pre heated oven for 20 - 22 minutes or when tested with a skewer it comes out clean.
7. Very carefully, tilt the cake over onto a wire rack so that the top side is underneath. Remove the foil and leave the cake to completely cool before removing the parchment paper.
8. Once the genoise sponge is cooled, to remove the sponge from the tin, run a sharp pairing knife around the side to release.