I remember hearing about many olive oils not being legit. The Italian mafia had a hand in this scam I believe.
There is a kind of documentary on this topic on youtube. The one I saw had a distributor of olive oil complaining that he cannot sell the real stuff primarily because the olive oil on the shelves is cut with vegetable oil and normal people think that is real olive oil.
The other reason was price, the real stuff is expensive in North America.
What I find weird is that if you go to medeterranian countries, a lot of families have their own groves and have the real stuff made by them selves and the extra is sold super cheap. It's really odd why a tiny bottle of the real stuff (certified) costs like $25 bucks.
It was wroth trying it, but I didn't like it very much.
In mediterranean countries you can easily buy it from the source and the price is usually somewhere between 3-5 euros. If you can't find it at a proper price, it's better to use oils produced locally, which often have good health benefits. For example, sesame oil is excellent.
The thing with olive oil is that it can be used to heat the pan as well without producing the unhealthy byproducts of other oils. The Chinese traditionally use a different kind of oil to heat the pan and a different kind of oil as a topping at the end.
It's not just the mafia, many unscrupulous producers will cut it to maximize their profit. You have to know where you buy from. The bottled product you can buy from a supermarket store is often found to be cut and they are legal consequences for the sellers. You hear such news all the time in Greece, so I guess it's much worse with the stuff that ends up in other markets.
(post is archived)