Cooking with olive oil
Olive Oil for Cake: Baking With Extra Virgin
Olive oil bakes a different cake from butter rather than a worse one, and the conversion between them is a ratio a home baker can carry in their head.
The short answer
Olive oil replaces butter in a cake at roughly three-quarters the volume, so 100 g of butter becomes about 75 ml of oil. The crumb comes out looser and stays soft for longer. A fruity extra virgin belongs with citrus, chocolate and spice; delicate sponges want a gentler oil.
A cake made with olive oil is not what you settle for when the butter runs out. It is a different cake: looser crumb, a softer slice on day two, a low fruitiness under the sugar.
Here is the conversion that works, which bakes want a strong oil, and why the oven dial worries bakers more than it should.
The butter-to-oil conversion
Swap butter for olive oil at roughly three-quarters the volume: 100 g of butter becomes about 75 ml of oil. Butter is part water and part milk solids, so pouring the full volume of pure fat into the bowl gives a greasy crumb. Recipes that melt their butter convert most cleanly of all.
| Butter in the recipe | Olive oil to use | Where this comes up |
|---|---|---|
| 50 g | 38 ml | Muffins, a tray of brownies |
| 100 g | 75 ml | A single 20 cm layer |
| 125 g | 95 ml | A loaf cake |
| 200 g | 150 ml | Two layers, or a bundt |
| 1 cup | 3/4 cup | American recipes |
Whisk by hand rather than reaching for the mixer: there is no butter to cream, and beating only toughens the crumb. If the batter looks stiffer than the recipe describes, loosen it with a tablespoon of milk.
Which bakes convert and which refuse
Anything that starts with melted butter converts: brownies, banana bread, carrot cake, muffins, most chocolate cakes. Anything built on creamed butter and sugar does not, because the air whipped into solid butter is the lift. Shortbread, laminated pastry and buttercream need the butter to stay butter.
- Converts well. Brownies, banana and date loaves, carrot cake, chocolate cake, muffins.
- Converts with care. Sponges and chiffons, where a milder oil keeps the flavour clean.
- Do not convert. Shortbread, flaky pastry, buttercream, anything creamed.
Why an oil cake stays moist longer
Butter is solid at room temperature and olive oil is liquid, and a cake behaves the same way. Butter in a cooled crumb sets firm, which is why a butter cake tightens overnight and tastes best warm. Olive oil stays liquid at Malaysian room temperature, so the third-day slice is still soft.
The batter is what the oil sees, not a hot pan
Bakers hesitate over extra virgin in a 180 °C oven because they are picturing a frying pan. A batter is mostly water, sugar and flour, and while it bakes the crumb sits near boiling point, not at the oven's air temperature. The oil is suspended in that, never against hot metal.
A cake's exposed edge and a focaccia crust do get hotter, and both sit well inside what this oil takes. The figures are in what heat olive oil can take.
Fruity oil or mild oil for the bake
Match the oil to how much else is happening in the bake. A green, peppery extra virgin has flavour to spare and needs a partner loud enough to meet it: dark chocolate, citrus zest, cinnamon and clove, wholemeal flour. A pale vanilla sponge has nothing to hide behind and wants a gentler, riper oil.
The peppery catch you taste from a spoon does not survive the oven intact. What reaches the plate is fruit and a faint savoury note, which is why a batter that tasted alarming raw comes out balanced.
Citrus and olive oil, and one worked ratio
Citrus and olive oil work together because both carry their aroma in fat. Rub the zest into the sugar with your fingers before anything else goes in the bowl, and the oil in the peel spreads through the sugar, then through the batter. Juice alone gives you sourness, not the smell of a lemon.
- Rub the zest of two lemons into 180 g caster sugar until damp and fragrant.
- Whisk in three eggs, then 150 ml olive oil in a thin stream, then 120 g yoghurt.
- Fold in 200 g flour, two teaspoons baking powder, a pinch of salt.
- Bake in a lined 20 cm tin at 175 °C for 40 to 45 minutes.
- Cool in the tin, and slice it the next day.
The short version
Three-quarters the volume of butter, whisked not creamed, in anything that would have used melted butter anyway. Strong oil for chocolate, citrus and spice, a gentler one for a plain sponge.