How to get real olive oil

That bottle of extra virgin olive oil you take off the grocery store shelf may not be what you think it is.

Instead of being a greenish-gold, fruity, fresh oil made from olives, rich in antioxidants and delicious to drizzle over a beautiful caprese salad, more likely than not it is a blend of oils, some made from olives, and some not.

In fact, a recent study by researchers at the University of California, Davis, that tested a number of the best-selling olive oils , including Bertolli, Star, Berio, Colavita, Mazzola, Carapelli and Whole Foods, found that 69 percent of the extra virgin olive oil imported into the U.S. did not meet the standards for extra virgin.

“It’s a big hoax,” said Tom Mueller, who wrote the book, “Extra Virginity: The Sublime and Scandalous World of Olive Oil,”. “What’s written on the bottle does not guarantee what is inside.”

Mueller, who lives in a medieval stone farmhouse surrounded by olive groves in Liguria, Italy, stumbled into the murky world of black market olive oil in 2007, when he agreed to write an article about oil for The New Yorker. What he found surprised him.

“I figure I am living in Italy,” said Mueller, 48. “I’ve been eating some good olive oil. Italy is the world center of olive oil. Surely it would be an easy, folksy story. I had no idea what I was getting into — the collusion, the crime, talking to investigative magistrates.”

The result of his research was “Slippery Business,” an article that shook up American palates by showing how many large companies pass off inferior oil as extra virgin olive oil. Since neither the U.S. Department of Agriculture nor the Italian equivalent really regulates the market, unscrupulous producers have developed numerous ways to adulterate extra virgin olive oil, according to Mueller. They cut olive oil with hazelnut or sunflower oil. They take musty oil made from rotting olives, deodorize it to remove the bad smell, and then add a bit of extra virgin oil to make it smell authentic. Then they slap fancy labels on glass bottles and sell it as extra virgin olive oil.

Some of the worst oil goes into industrial food, said Mueller.

“There’s a river of rotten oil going into food service — restaurants hotels, schools, hospitals,” he said. “The big companies are selling things that are not even olive oil.”

Most of the olive oil stocked in a grocery store is not as bad as the industrial oils, said Mueller. But the UC Davis test showed that even though the supermarket oils were branded extra virgin, much of the time they were only of virgin quality.