Hello Dave,
Sponge cake can be quite tricky to adapt without eggs because traditional recipes rely on them for two crucial roles: aeration (trapping air to create volume) and structure (egg proteins setting during baking so the cake stays upright). When eggs are omitted without balancing both elements, the cake almost always collapses in the center.
If you want cheap, reliable substitutes that keep the cake fluffy and prevent sinking, here are the two most effective methods:
1. Aquafaba (Chickpea Brine)
This is the most authentic replacement for sponge cakes. Drain the liquid from a can of chickpeas and use 3 tablespoons per whole egg. Whip the liquid using a hand or stand mixer with a pinch of cream of tartar or lemon juice until it reaches stiff, glossy peaks, exactly as you would with egg whites. Gently fold this foam into your sifted dry ingredients at the very end. It traps air exceptionally well and leaves no bean flavor in the finished bake.
2. Baking Soda, Vinegar, and Cornstarch
If you prefer not to use aquafaba, you can rely on an acid-base reaction combined with starch. For each egg, combine 1/2 teaspoon of baking soda with 1 tablespoon of white vinegar or apple cider vinegar, along with 2 tablespoons of milk or water. To keep the crumb from sinking, substitute 1 to 2 tablespoons of your flour with cornstarch. The cornstarch helps set the delicate structure without weighing down the batter.
To ensure your eggless sponge does not sink, remember these three rules:
- Sift your flour and dry ingredients to maximize airiness.
- Avoid overmixing once wet and dry ingredients meet, and get the tin into the preheated oven immediately.
- Keep the oven door closed for at least the first 25 minutes of baking, as sudden temperature drops will cause the fragile crumb to deflate.
I hope this helps you achieve a tall, tender sponge cake without stretching your budget.
