Tips to avoid problems with sponge cake
Sponge cake is one of the best known and most widely used preparations in pastry-making.
There are many possible combinations and the balancing of its ingredients vary according to the required final use (stuffed cakes, roulades, ladyfingers, bases, chocolate pastries, etc.)
The processing systems also vary:
- Hot method
- Cold method
- Separate ingredients method
- Whole eggs method
- Whole eggs method with the addition of yolks
- Added fats method (Margherita dough)
Despite the multitude of recipes, they all share one common ingredient.
I’m sure you’re wondering: Is it…
None of the above!
The key ingredient for great results is:
Yes, this is the most interesting element, because it is what makes the difference between an excellent sponge cake and a “frisbee”! (pass me the term).
Of course, we won’t weigh air and no equipment exists to incorporate it (except for sponge cake processed with a siphon).
The crucial technique then is the beating of the eggs:
Beating and whipping involve incorporating air into a usually liquid element, such as eggs or cream.
For this step a stand mixer is commonly used.
In this article I will focus on the purely practical aspects of the hot fats method with whole eggs (Genoise).
(26 cm diameter baking pan)
- Whole eggs 300 g (6 items)
- Sugar 180 g
- Flour 150 g
- Starch 50 g
- Lemon zest, grated
The first step is to heat up the eggs with the sugar (in a bain-marie or with short microwave sessions):
eggs will incorporate the largest amount of air at a temperature btw 40 and 45°C.
Beating eggs that have just been removed from the refrigerator will greatly lengthen your production time and the outcome will not match your expectations (small cavities).
How long do I have to whip my eggs?
Usually sponge cake should be whipped up 10/12 minutes.
In any case, never exceed 20 minutes because otherwise you risk enervating the protein network.
The eggs must increase by 5 times their volume: when the whipped mix is ready the whisk will form “the ribbon” in the batter of eggs and sugar.
At this point you can proceed to add the flours.
Sieving the flour beforehand is very important to avoid the formation of lumps.
This is the only way to evenly mix starch and flour together.
Flours can be added in 2 ways:
- by hand -mixing from the bottom up to the top, without causing the compound to lose air;
- in a stand mixer – in 2 steps, gradually reducing the mixing speed.
The baking pan should be buttered and floured, sprayed with a non-stick spray or lined with parchment paper.
Baking times and temperatures vary from one oven to another: approximately 180/190°C for 20/25 minutes in a static oven and 160/170°C in a ventilated oven.
Frequently Asked Questions
Why does my sponge cake deflate when I add the dry ingredients?
The common mistake lies in the way eggs are beaten:
Use a whisk with thin wires (they incorporate more air) and avoid mixing the batter too fast in the stand mixer.
Excessive speed forms larger and more delicate air bubbles which collapse more easily while incorporating the flours, thus making the dough lose volume.
Creating smaller bubbles makes the whipped mixture more stable.
When adding the flour try and take a little beaten dough at a time, then turn the container automatically.
My advice is not to over-mix the batter; if you do, the gluten is activated and could make your cake rise in the middle during cooking.
- Why does my sponge cake dome in the middle?
As written above, this is caused by the gluten activation or the use of inadequate flours (with too much protein).
This is the reason why the flour is usually “blended” with starch.
If fats are added (like in the Margherita dough) they should be melted and never be hot:
it is always advisable to take some whipped mixture and add it into the fat, emulsify it like a mayonnaise and then add it to the rest of the dough.
With this technique the fat is perfectly incorporated into the dough without leaving deposits on the bottom of the bowl.
How can I tell when it is cooked?
There are different ways to do it:
the sponge cake sides pull away a few millimeters from the edges of the pan.
Delicately touch the surface of the sponge cake with your hand: if no finger marks remain the dough is perfectly cooked.
it must come out dry, without residual liquid dough.
- Why does the cake collapse in the middle when I remove it from the oven?
This can be due to a lack of structure:
adding 20% starch to the quantity of flour will stabilize your sponge cake.
My last useful trick, (though not always feasible since blast chillers exist only in professional laboratories), is to use a blast chiller just after baking:
this will ensure a greater amount of moisture, keeping the cake softer over time.
Have a nice dessert!