Basic Baking Ingredients – The Secret Ingredient…..Air

Sponge cake is the cornerstone cake for most cake decorators and bakers. It is usually formulated from equal weights of sugar, butter, flour and eggs; however, the one ingredient never listed is ‘air’.  But it is air that fundamentally makes or breaks this classic recipe and, sadly, this is the one ingredient that you can’t buy. Yet, there are techniques you can use to optimize the air you add into your mix and keep it there! Armed with this knowledge, you will be well on your way to baking the lightest, fluffiest cakes.


Make sure that all your ingredients are at room temperature. Cold butter will take much longer to mix with sugar during ‘creaming’. This can cause overmixing, resulting in a heavy cake. On the other hand, if the butter has become too warm and lost its structure, the cake will have an oilier, heavier consistency. Fresher egg whites will whip up with more air than older, cold ones whose structure struggles to support the air.

Always use castor sugar, as the molecular makeup of its crystals encourage more air to get trapped. And always sift the cake flour a few times prior to folding it in with the wet ingredients. Again, you will be incorporating more of the magic ingredient, air!


Your utensils are just as important as your ingredients. This does not mean that you need anything fancy, but just an understanding of why some things work better than others. An electric mixer will automatically allow you to work more air into your mix, not to mention save you from a very tired arm! Try to avoid using a plastic bowl when mixing eggs, as the plastic inhibits the eggs from whipping up properly. Use either a large metal spoon or thin spatula when folding in the flour. If you use a wooden spoon (or your mixer), you will crush all of the air out. And make sure that you always use the correct size pan for the recipe as the depth of the pan is especially important for allowing a good rise. A lighter colored pan is also preferable as darker pans concentrate heat and encourage a darker crumb.


Before you get started, make sure that you have prepared your pans, preheated the oven and arranged the shelves correctly. If your cake is left too long before baking, it will start to lose volume. Weigh carefully, as too much fat or sugar will crush the supporting air structure. Make sure that at every stage of the mixing process you try to optimize working in as much air as possible. Take time to really cream the butter and sugar until it is a similar consistency to whipped cream. The majority of air is added at the creaming stage and your aim is to coat all the sugar crystals with a film of fat. This fat will trap in air, which will expand with steam when baked, thus creating a light and airy cake! Add the beaten eggs slowly.

Your oven temperature is crucial to get right. Too low and the air in the cake will not expand quickly enough. This will cause the surface to sink and the cake to be heavier with a coarser crumb. If the oven is too hot or the cake placed too high, the outer parts of the cake will expand and cook quicker than the middle. This will result in a volcanic dome on the surface of the cake. Invest in an oven thermometer, but make sure to put it on the shelf you intend to use, ideally in the middle. Most importantly, do not open the oven door at the early stages of baking, as this could result in the cake sinking in the middle.

sponge cakeRecipe:

    • 200g unsalted butter, softened, plus extra for greasing
    • 200g caster sugar
    • 1 tsp vanilla extract
    • 4 medium eggs, beaten
    • 200g self-rising flour (ideally cake flour), plus extra for dusting
    • pinch of salt

Grease and line 2 x 20 cm sponge cake pans

Preheat the oven to 180C

  1. Sift the flour 3 times.
  2. Cream together the butter, sugar, vanilla and salt until light and fluffy.
  3. Add the eggs a little at a time until fully incorporated. If it starts to curdle, add 1 tbsp. of the flour.
  4. Sift in the flour in two parts. Gently fold until incorporated.
  5. Divide between the pans and bake for approximately 20 minutes or until firm to the touch and the cake is pulling away from the sides of the pans.
  6. When your cake is cool, fill with your favorite filling, dust with a little icing sugar and enjoy that light, fluffy bite!

I’d love to hear your thoughts. Please leave your comments or questions below.

Leave a Reply

Your email address will not be published. Required fields are marked *