Tunisian, Spanish and Italian olive oil: what differs

Italy and Spain are the best-known names in olive oil, and many buyers take the name itself as a mark of quality. It is not. All three countries produce excellent oil and unremarkable oil alike.

The thing most often misunderstood

A bottle packed in Italy does not necessarily contain Italian oil. Olive oil is traded internationally in volume, and bottles can be filled in one country with oil grown in another.

This is why labels reading "blend of EU olive oils" or "blend of EU and non-EU olive oils" exist. Those labels are honest — they tell you the origins are mixed. But they also mean you do not know where the oil came from.

Why single origin matters

Single-origin oil comes from one country, and often from an area considerably smaller than that. Two things follow.

1. 1.The flavour stays consistent between bottles and across seasons, because it comes from the same groves and varieties
2. 2.The oil can be traced. A laboratory report refers to an actual batch, not to a blend that keeps changing

Tunisia

Tunisia is one of the world's largest olive oil producers, and has been for a very long time — olive cultivation there goes back thousands of years. Much of its output has traditionally been exported in bulk to Europe, where it is bottled under other names.

That means a great many people have eaten Tunisian olive oil without knowing it. What has changed more recently is that more Tunisian oil is bottled at source and sold under its own name.

What to check, whatever the country

• Free acidity as a number, with the laboratory's name and a report number
• A harvest date, not only an expiry date
• A single country of origin, not "blend"
• The words "extra virgin", not "pure" or "light"
• Dark glass or a tin
• Bottled at source, where the producer states it

That list will tell you more about a bottle than the flag on the label.