Why Olive Oil Belongs in Your Baking Tin

Walk into a kitchen in Puglia or Provence and you will find olive oil in the cake tin as often as butter. It is not a compromise born of necessity; it is a preference. Oil keeps a bake tender and moist for days, it carries the flavour of citrus zest and vanilla beautifully, and it means a single bowl of batter can be mixed by hand in a few minutes.

Because oil is liquid at room temperature, it coats the flour proteins before they can form long gluten strands. The result is a softer, more open crumb — less structural than a butter cake, but far less prone to drying out. Cakes made with olive oil are often at their best on the second or third day, which is more than can be said for many butter sponges.

And then there is the flavour. A good mild olive oil brings a faint green, fruity note — something between freshly cut grass and almond — that flatters chocolate, lemon, orange, rosemary and dried fruit.

Which Olive Oil to Choose

The single most useful rule: bake with an oil you would happily dip bread into, but not the most assertive bottle in your cupboard.

• Mild extra virgin olive oil — the sweet spot for most cakes. Look for gentle, buttery styles, often from later harvests.
• Everyday or classic olive oil — a blend of refined and virgin oil. Cheaper, mild and reliable in strongly flavoured bakes such as chocolate or ginger.
• Light or refined olive oil — almost neutral in taste. Useful when you want the texture of oil without any flavour at all.
• Avoid peppery, pungent oils — a robust, throat-catching oil can turn a delicate sponge bitter once baked.

Freshness matters more than price. Olive oil dulls with age, and an oil past its best will taste flat and slightly waxy in a cake. Buy in smaller bottles, keep them in a cool dark cupboard away from the oven, and use within a year or so of harvest.

How to Swap Butter for Olive Oil

Butter is roughly 80 per cent fat and 20 per cent water, so you need less oil than butter. As a rough guide, use 80g of olive oil for every 100g of butter.

• By weight: multiply the butter weight by 0.8. So 200g of butter becomes 160g of olive oil.
• By spoon: 1 tablespoon of butter is about three-quarters of a tablespoon of oil.
• Melted butter to oil: swap one for one by volume, then add a splash less.

Some recipes convert more gracefully than others. Loaf cakes, muffins, brownies, carrot cake, polenta cake and oil-based sponges are ideal. Recipes that depend on creaming butter and sugar for their lift — a classic Victoria sandwich, for instance — are better left alone, or made with half butter and half oil.

Flavour Pairings That Work

Olive oil is a savoury ingredient at heart, and it likes company that can stand up to it.

• Lemon and orange — zest in the batter, juice in the drizzle. A mild oil lets the citrus sing.
• Chocolate — a fruity oil with dark chocolate is a classic pairing; the bitter edge of cocoa softens the oil's green notes.
• Rosemary and thyme — a sprig, or a teaspoon of finely chopped leaves, in a lemon or apple cake.
• Almond and pistachio — ground nuts and olive oil share a certain roundness.
• Dried fruit and spice — figs, raisins, cinnamon, cardamom. Perfect with a plain everyday oil.

Biscuits, Shortbread and Crumbly Things

Biscuits behave differently. Butter gives shortbread its snap and its melt; oil gives a crisper, denser bite that is excellent for dunking but is not the same thing at all. Where olive oil really earns its place is in the Mediterranean biscuit tradition — think Italian olive oil and lemon biscuits, aniseed rings, or thin rosemary wafers.

For these, a simple ratio works well: about 100ml of mild olive oil to 300g of plain flour, with 100g of caster sugar, an egg and a little baking powder. The dough is soft and slightly crumbly; chill it for half an hour before rolling and it will behave. Bake at 170°C fan until the edges are just golden — the colour deepens quickly once the oil has warmed through.

One thing to watch: oil-based biscuits spread more than butter ones. Keep the dough and the tray cold, and line your tins with baking parchment rather than greasing them.

Practical Tips for Reliable Results

• Bring the oil to room temperature; cold oil can make a batter look curdled.
• Whisk the oil with the sugar and eggs first, then fold in the flour. This helps the batter emulsify.
• Let the batter rest for 10 minutes before baking. The flour hydrates and the crumb improves.
• Oil-based cakes brown faster on top. Check five minutes early, and cover loosely with foil if needed.
• Drop the oven temperature by 10°C if your bake is catching.
• Store the finished cake in a tin rather than the fridge; oil keeps it moist without chilling.
• Taste the oil first. If it tastes good on bread, it will taste good in cake.

Baking with olive oil is less about substitution and more about a different tradition altogether — one where the fruit bowl, the herb pot and the oil bottle sit side by side on the worktop. Start with a plain lemon loaf, use a mild oil, and taste as you go. Before long you will find yourself reaching for the bottle without thinking twice.