Extra virgin or light olive oil: what the difference really is

This is the most expensive misunderstanding on the olive oil shelf. Many buyers assume "light olive oil" means lower in calories or fat. It does not, and the real difference matters.

What "light" actually means

It refers to flavour and colour. A "light" oil has been refined until almost no taste, smell or colour remains. It is pale and neutral — and that is what "light" describes.

In terms of fat and energy, all olive oil is essentially the same. A tablespoon of "light" oil contains as much fat as a tablespoon of extra virgin.

The grades that actually exist

• Extra virgin — mechanically pressed, no detectable flavour defects, free acidity up to 0.8%
• Virgin — mechanically pressed, minor defects allowed, free acidity up to 2.0%
• Pure or just "olive oil" — refined oil blended with a little virgin or extra virgin
• Light or extra light — the same as pure, with even less flavour
• Pomace — extracted from the leftover olive solids with solvents, then refined

Note that "light" and "pure" sit in the same category. The word "pure" misleads too — it does not mean purer than extra virgin. It means refined oil.

What refining removes

Refining uses heat, and sometimes chemicals, to strip flavour, smell, colour and acidity out of oil that did not meet the extra virgin standard. It also strips out the polyphenols — the compounds behind fresh olive oil's peppery, bitter character.

There is nothing unlawful about this and the oil is safe to eat. But if you are buying olive oil for its flavour, refined oil will not give you any.

When "light" does make sense

It has one legitimate use: cooking where you do not want any olive flavour but do want a neutral oil with a high smoke point. Baking a light vanilla sponge, or frying where an olive note would clash.

For that use, check the price. Refined oil should cost less than extra virgin, because it is made from lower-quality oil to begin with. If it costs the same, you are paying for the word on the label.

For salads, dipping bread, and anything served raw, use extra virgin. Flavour is exactly what refining removes — there is nothing left to taste.