The Beginner’s Guide to Vegan Cake Chemistry

Catherine Lawson

Experimenting with vegan cakes can be soul-destroying if you don’t have a few basics up your sleeve to help you navigate the science of baking. Understanding the essentials of cake chemistry can help you enjoy consistently successful results.

The two key things most sponge-based cakes need are structure and lift. In traditional baking it’s eggs and butter that give you this so when you strip these elements out you need alternatives. Here’s what to do:

Instead of using real eggs use flax ‘eggs’ (details below). Ground flaxseed, when mixed with water, creates a gelatinous substance, much like an egg white. This means that when you add it to a cake recipe it has a similar effect; it becomes the emulsifier and binder that gives your cake structure. Mashed banana and applesauce are other alternative egg replacements, however, flax eggs provide the most consistent and effective result without any lingering after-taste.

Butter is also traditionally used as a binder in cakes in addition to being a source of richness and flavour. For vegan sponges, swap butter for a plant-based margarine such as Flora or Stork (many a baker swears by the latter for the perfect sponge) or switch over to using oil as the fat source. Using oil means a change in method (you’d use the wet/dry method where the wet ingredients are mixed together first before adding the combined dry ingredients), but it provides the moisture, flavour and binding qualities you need for a good end result.

Eggs, specifically the whites, once whipped add lift to your cake. Without them there’s a risk of cakes being dense unless you add a substitute. The easiest way to do this is to add baking soda and vinegar which, when combined, have a chemical reaction that effectively puts air into the mix. The baking soda, along with baking powder, can be enough if you’re looking for a heavier sponge base with a rise on it (for example the banana loaf recipe below) but if you’re baking a sponge cake where you want lightness and lift, the baking soda and vinegar combo is a must.

Ready to give it a go? Try this delicious banana loaf recipe to get you started.

Vegan banana and walnut loaf recipe:

  • 2 flax eggs
  • 4 medium, ripe bananas (3 mashed, 1 cut lengthways for decoration)
  • 75ml light olive oil
  • 100g golden caster sugar
  • 1 tbsp demerara sugar
  • 1 tsp vanilla extract
  • 200g plain flour
  • 1 generous tsp baking powder
  • ½ tsp bicarb of soda
  • 1 tsp mixed spice
  • Large pinch salt
  • 70g walnut pieces
  1. Preheat oven to 175c. Grease and line a 2lb loaf tin.
  2. Prepare the flax eggs and set aside.
  3. In a large mixing bowl, mash the bananas then beat in the oil, sugar and vanilla. Add the flax eggs and combine well.
  4. In a separate bowl, sift the flour, baking powder, baking soda, mixed spice and salt together.
  5. Add the flour mix to the banana mix, beating until just combined. Stir the walnuts through.
  6. Pour the mix into the prepared loaf tin and top with the whole banana which has been cut lengthways (inside edges facing up). Sprinkle the demerara sugar on top.
  7. Bake in the oven for approx 55 minutes or until a skewer comes out clean.
    *Flax eggs:
    To make one flax egg mix 1 tbsp of ground flaxmeal with 3 tbsps cold water. Leave for five minutes for the mixture to become gelatinous and ready to use.
    One flax egg, as above, equals one large egg.