Ingredient

Olive oil

Olive oil is two ingredients in one bottle shape: a cooking fat, and a seasoning you pour on at the end. Most of the confusion around it comes from treating a bottle bought for one job as though it were for the other.

The grades

These are legally defined in the EU and UK, and the definitions are about how the oil was made and how much free acidity it has — not about flavour, though the two correlate.

Extra virgin

Pressed mechanically, no heat or solvents, low acidity, and it must pass a taste panel. Fruity, peppery, sometimes bitter — all three are signs of quality, not faults.

Virgin

The same process, slightly higher acidity and a less strict sensory standard. Less common on shelves.

Olive oil, or "pure"

Refined oil blended with a little virgin oil. Neutral, pale, cheaper. A perfectly good cooking fat with almost no olive flavour.

Light or extra light

A marketing term about colour and flavour, not calories. Refined oil with very little virgin in it.

Olive pomace oil

Extracted from what is left after pressing, using solvents, then refined. Industrial frying oil.

Can you fry with extra virgin olive oil?

Yes, for most home cooking. The idea that it is unsafe to heat is overstated: extra virgin olive oil smokes somewhere around 190 to 210°C depending on the oil, which is above sautéing, shallow frying and almost all roasting.

The real objections are different and more practical. It is expensive, and the delicate aromatics you paid for are the first thing heat destroys, so frying with a good bottle wastes it. And for deep frying, where the oil is held hot for a long time and reused, a refined oil with a higher smoke point and a neutral flavour is simply better suited.

So: cook with ordinary olive oil or a neutral oil, and keep the extra virgin for finishing, dressing and gentle cooking where you want to taste it.

Using it as a seasoning

This is where a good bottle earns its price, and all of it happens off the heat.

• Over soup, beans and pulses just before serving. A swirl on a bowl of lentils changes the dish completely.
• On bread, with salt, which is the simplest way to find out whether you like a particular oil.
• Over grilled or roasted vegetables after they come out of the oven, not before they go in.
• In a dressing, where the bitterness and pepperiness are structural rather than a flaw — three parts oil to one of acid is a starting point, not a rule.
• On fish, and on tomatoes, both of which need very little else.

Buying and storing

• Dark glass or tin, never clear plastic. Light is what degrades olive oil fastest.
• Look for a harvest date, not just a best-before. Olive oil does not improve with age; a year from harvest is already past its best.
• Peppery is good. A catch at the back of the throat is a sign of the phenolic compounds that fresh, well-made oil contains.
• Keep it in a cupboard, not next to the hob. Heat and light are the two enemies, and the shelf above the stove has both.
• Do not refrigerate it. It goes cloudy and semi-solid, which is harmless but pointless.

Which oil for which job

• Extra virgin, good quality — for dressings, finishing, dipping and anything raw. This is where you taste it, and where the price is justified.
• Ordinary extra virgin — for everyday cooking at moderate heat. Perfectly suited to sautéing and roasting.
• Light or refined olive oil — higher smoke point, almost no flavour. For frying, where a good oil would be wasted and its flavour compounds destroyed anyway.
• Not for deep-frying as a rule — the smoke point is workable but the cost is not.
• Not blended hard in a machine. Shearing olive oil releases bitter compounds, which is why blended pesto and processor-made mayonnaise can taste harsh. Stir or pound it in instead.
• Store it cool, dark and sealed. Light and heat turn it rancid, and a clear bottle on a sunny worktop is the worst place in the kitchen.

Common questions