7 Myths (and Truths) About Olive Oil

7 Myths (and Truths) About Olive Oil

Why olive oil makes better muffins and a few other little-known facts about the good fat that’s even better than you think. Here are three recipes for cooking with olive oil, plus tips for buying and cooking with this versatile, healthy fat

By Nancy Harmon Jenkins in the Wall Street Journal

MYTHS, legends, half-truths and outright lies about olive oil so pervade our current conversation about food that an oleophile like me hardly knows where to begin to refute them. Here are just a few I’ve seen or heard recently: Most imported olive oil is an impostor, especially if it comes from Italy; instead it’s actually Moroccan crankcase oil or worse. You can’t cook with extra-virgin olive oil because it will either burst into flames or turn into a dreaded trans fat. Extra-virgin oil is from the first cold pressing, virgin oil from the second. A buttery taste means the oil is rancid. Extra-virgin is a good source of Omega-3 fatty acids.

None of that is correct.

Let’s get a few things straight, starting with this: The only olive oil worthy of consideration is extra-virgin. Anything else, whether labeled pure, light or just plain olive oil, has been heavily refined into a pallid, flavorless substance to which a little extra-virgin oil is added for color and flavor. It’s an industrial product, made to industrial standards. If that’s all your supermarket offers, opt for one of the other oils on the shelf.

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Extra-virgin olive oil should simply be the oily juice of the olive, minus the water also contained within the fruit. It may have been filtered, but it has not been refined. Because it is not standardized, extra-virgin varies enormously in aroma and flavor from bottle to bottle, producer to producer. The taste depends on many factors, from the variety of the olives pressed to their state of maturity to the speed and care with which they’ve been processed. Good cooks know to use those variations to advantage in the kitchen—maybe drizzling a big bitter Tuscan oil over a thick ribeye right off the grill; adding a softer, sweeter Ligurian taggiasca or Catalan arbequina to baked goods; or sautéing vegetables in a warm, enveloping Sicilian nocellara.

Still, the extra-virgin designation doesn’t necessarily mean the oil is any good. The protocols established by the International Olive Council are generous to say the least—so generous that fine producers go way beyond them. Fortunately, I’ve learned a few things over four decades of researching olive oil and its place in the Mediterranean diet, and even producing it myself on my farm in Tuscany. Here are some signposts to guide you to the really good stuff, and tips to keep in mind when using it in the kitchen:

1. Buy oil in dark glass containers. Or, better yet, tins, and reject anything, even in a dark bottle, that an enthusiastic shopkeeper has displayed in a sunny window or under bright lights. It will have deteriorated within days. It cannot be said often enough that olive oil is extremely sensitive to heat and light.

2. Do judge by the price tag. Like the best wine, the best extra-virgin costs a lot. That’s because it is hand-harvested, pressed within hours of picking and milled locally, if not actually on the estate where the olives grow.

3. Be a label snob. Right there on the bottle it should state where the olives were grown, and possibly which varieties were used and where and when the oil was made. It may even give the free oleic acid content, a measure of rancidity, at the time of pressing. Producers of the best oil would never put a product on the market with a grade over 0.3%, and many find even that figure too high. Endorsements on the label—by which, I do not mean gold medals at the Paris World’s Fair of 1937—can also indicate quality. DOP, DO, DOC and PDO identify oil produced according to a “protected denomination of origin,” a certification controlled by the European Union, which includes top oil producers in Spain, Greece, Italy, Portugal, France and most recently Croatia. The California Olive Oil Council endorses high-quality oils produced in that state. Organic certification is also a good guarantee that an oil is what it claims to be.

4. Fetishize freshness. A harvest date included on the label conveys a producer’s pride; the most recent harvest (currently 2014-15 in the northern hemisphere) is best of all. And don’t be swayed by a “best by” date, which can be 18 months after bottling. Since the oil may already be a year or more old when bottled, you could be buying three-year-old oil without knowing it.

5. The phrase ‘first cold pressing’ is meaningless. It harks back to long-ago days when making oil was a slow, dirty process and the best and cleanest oil did, indeed, come from the first pressing of the olives. Today it’s a marketing ploy, like saying carrots contain no cholesterol or rice is gluten-free. To be extra-virgin, the oil must be pressed at ambient temperatures that ideally don’t go above 85 degrees Fahrenheit. There is no hot pressing of extra-virgin, and there is no second pressing, either.

6. Go ahead and turn up the heat. Because of its high polyphenolic content, extra-virgin is more stable than many other oils. The widely held belief that disaster lurks at temperatures above 250 degrees Fahrenheit is simply wrong. Extra-virgin remains stable up to about 410 degrees or a bit higher, depending on the extent of filtration (less filtered means lower temperatures). So deep-frying—best at 350 to 360 degrees—is more than acceptable. Use olive oil in baking too: Cakes gain a moist, rich texture when it’s swapped in for butter, as in the recipe for gluten-free blueberry muffins above.

7. Just don’t expect to get your daily allowance of Omega-3s. If extra-virgin olive oil displays more than a trace of Omega-3 fatty acids, that suggests contamination by another oil, most likely canola. Extra-virgin is extraordinarily good for us, but not because of its Omega-3 content. Rather, it’s all those antioxidants that have been shown to contribute to the defense against all manner of chronic diseases. You know an oil is high in antioxidant polyphenols when you can taste bitterness and pepperiness. The fact that those qualities also add complexity and intensity to whatever you’re eating seems almost—almost—too good to be true.

Ms. Jenkins is the author of “Virgin Territory: Exploring the World of Olive Oil” (Houghton Mifflin Harcourt).