As with many things in life, mayonnaise is more than the sum of its parts. And the magic that happens when eggs, acid, and oil come together is exactly why you should be adding it to your cake batter. (Spoiler alert: It’s not just because mayo is fatty and creamy, although that never hurts.)
🍰 How does mayo work its magic in cake batter?
Mayonnaise is a stable emulsion created by combining eggs and vinegar with oil. Unlike most proteins, the structures in eggs can bind with both water and oil molecules, enabling a thick and velvety texture that isn’t greasy.
Adding the unique fat-suspending properties of mayonnaise to your wet ingredients helps them thoroughly coat the flour particles in the batter, essentially trapping the dry ingredients in fat.
On their own, oil and egg are key ingredients in many cake recipes: oil helps create a soft texture, while eggs provide structure. But, these ingredients are stronger together (and do more for your batter) when emulsified into mayonnaise. That’s why Claire King’s recipe for The Best Chocolate Cake uses butter for fat, eggs for protein, and mayonnaise for an extra boost of both — and that special food science X-factor.
🫧 There is yet another reason mayo belongs in your cake…
It’s the condiment that keeps on giving. The vinegar in mayonnaise can also help improve your cake-making. As you may know, baking soda is a common leavener for cakes and many baked goods, and baking soda needs acid to activate and create the air bubbles that make cakes rise. The vinegar in mayonnaise boosts the batter’s acidity slightly, helping the baking soda work more effectively for an evenly light and fluffy cake.
Grandmas and pastry chefs alike swear by this trick for ultra-moist cake layers. But if you’re still skeptical, just download the free Tasty app and scroll through the thousands of users who raved about our ultimate mayonnaise-wielding chocolate cake recipe.