As much as 50 percent of the olive oil sold in the U.S. is not actually pure olive oil, as some brands claiming to be “extra-virgin” or “100 percent Italian,” for instance, have actually been adulterated with toxic rapeseed oil, more popularly known as canola oil, soybean oil, and other low-grade oils. In his new book Extra Virginity: The Sublime and Scandalous World of Olive Oil, olive oil expert Tom Mueller explains that not all olive oil is the same, and offers advice on how to spot authentic olive oil amidst all the imposters.

During a recent interview with Terry Gross from NPR‘s Fresh Air, Mueller explains how olive oil adulteration is much more widespread than people think, if they are even aware of it at all. For olive oil to truly be considered “extra-virgin,” it has to come from fresh, crushed olives, and not be refined in any way or contain any chemical solvents. It also has to pass certain tests of integrity in order to be considered legitimate, for which many of the brands popularly sold today would fail.

“The legal definition simply says it has to pass certain chemical tests, and in a sensory way it has to taste and smell vaguely of fresh olives, because it’s a fruit, and have no faults,” said Mueller. “But many of the extra-virgin olive oils on our shelves today in America don’t clear [the legal definition].” Continue reading →