Not all olive oil is created equal, though, and while there are different kinds—extra virgin olive oil, light olive oil, just plain ol’ olive oil —if you’re looking for an everyday oil you can use for almost all your cooking, the options get narrowed down pretty quickly. (Spoiler alert: we use extra virgin for almost everything).
How Olive Oil Is Made
Olive oil isn’t only food; it’s human history. A bedrock of the Mediterranean cuisines we love so well, olive oil is a cooking fat, a flavor agent, and a way of life. Olives are a fruit, and good olive oil is olive juice – fatty olive juice. Olive harvests happen in October and November. There’s a rush to press the olives, as olives develop undesirable acids every minute they spend just hanging out after harvesting. (Time is of the essence with olive oil. It does not get better with age!) While some extra virgin olive oil is still pressed using stone mills not dissimilar from what was used hundreds of years ago, innovations have improved speed and yield while reducing temperature. Why does temperature matter? You get better olive oil from olives that have been exposed to less heat. Freshly pressed olive oil is full of particulate matter, which makes it cloudy. Cloudiness is not a marker of poor quality; in fact, it means the oil is a gourmet product, with a fuller flavor! Oil pressed at the beginning of the season has a grassier, more assertive flavor than oil pressed near the end of harvest, which tends to be mellower. These differences are part of what makes olive oil so alluring and special. The process above describes extra virgin olive oil only. The extractions of refined olive oil and olive pomace oil are very different. Those products require heat and chemicals for extraction, which significantly changes the flavor, color, and nutritional profile of the oil.
The Types of Olive Oil
Not all olive oils are the same! Here’s the lowdown on olive oils commonly available to home cooks.
Extra Virgin Olive Oil
This is the highest grade of olive oil. If you’re going to buy one bottle of olive oil for all your cooking needs, from sautéing to salad dressings, this is what you should buy. It’s the good stuff that runs first out of the presses. When you see “first cold-pressed” on the label, it’s because no heat was used in extracting the oil. International Olive Council trade standards state olive oil cannot be labeled “extra virgin” if it is not first cold-pressed. But the real marker of an extra virgin olive oil is the level of free acidity, expressed as oleic acid, of not more than 0.80 grams per 100 grams. What does this even mean? Oleic acid develops as the olives rot, and that process begins very shortly after the olives are harvested. The sooner the olives are crushed after harvesting, the less oleic acid. This means extra virgin olive oil is made from olives that have had the least amount of rotting, which sounds pretty good to me! In addition to passing this chemical analysis, “extra” on the label also indicates that the olive oil passed a taste panel of judges. When I cook with olive oil, I want it to taste like olive oil, so I stick to extra virgin for everything. If I am making something and I don’t want it to taste like olive oil…I use another oil. Easy!
Virgin Olive Oil
Virgin olive oil is a quality step down from extra virgin oil, and there is a flavor difference. Its free acidity content is a little higher (not more than 2.0 grams per 100 grams). Virgin olive oil is fine for sautéing, roasting, baking, frying, and sauces, but it should not be used for dressing or finishing since the flavor is much less appealing.
Olive Oil
Plain ol’ olive oil is even lesser quality, a blend of refined olive oil with only 5 to 15% virgin or extra virgin olive oil. In the refining process, the oil is bleached, neutralized, and/or deodorized. And yes, on the label, that’s what it’ll read: just plain olive oil.
Since this is a refined product, it’s best to only use it for cooking where the flavor of the olive oil isn’t going to be center stage, like sautéing, roasting, and mid-temperature frying.
Light Olive Oil
Sadly, light olive oil is not like lite beer—that is, it’s not lower in calories. It’s just a lower quality olive oil that’s blended with other oils (usually highly refined ones) to give it a lighter color and flavor profile. Again, as a refined oil, it doesn’t offer the same health benefits as extra virgin or virgin olive oil, but you can use it for searing, sautéing, roasting, or mid-temperature frying. Avoid applications where you’d actually taste the flavor of the olive oil.
Olive Pomace Oil
Pomace oil is extracted from the pulp left after the olives are pressed. Chemical solvents like hexane and high heat are needed to get the last bit of oil from the mashed-up flesh, pits, and skins. Pomace oil is not a high-quality product. We recommend avoiding it.
How to Buy the Best Olive Oil
Always buy extra virgin olive oil. It’s not bulletproof, but it’s a good place to start. Opt for producers that have a harvest date, estate name, or mill name on the label. This is really one of the best indicators of both quality and authenticity. Look for certifications from organizations like the North American Olive Oil Association (NAOOA), the Olive Oil Commission of California (OOCC), or a DOP. Taste and smell your oil every few bottles to make sure it’s still delivering the quality and flavor you expect. Check the packaging. Good producers know to protect their products in dark glass bottles or metal tins because they protect the oil from damaging light.
How to Store Olive Oil
The #1 thing to remember about storing olive oil is to keep it away from light, air, and heat.
Your houseplants may thrive with light, air, and heat, but these three things are the sworn enemies of olive oil! They’ll cause it to go rancid. What is rancidity? It’s what happens when fats and oils break down and form undesirable new compounds. Rancid oil smells like old crayons and tastes like old nuts. It’s also not good for you.
Olive oil lasts longer in sealed bottles but deteriorates quickly once opened (remember, air is one of its enemies!). Once opened, a bottle should be used within 8 to 12 weeks . Keep a lid or cap on your open olive oil to minimize exposure to air, then store it in a dark cupboard. (Yes, it’s handy to keep your olive oil right next to the stove, but that’s a hot, light-filled spot. Bad!)
Stored correctly, sealed bottles of olive oil will stay good up to 18 months after pressing, but are best used within a year of pressing. Keep in mind this is after pressing, not after buying. How do you know when the oil was pressed? Some bottles will say, but most won’t. To be on the safe side, buy your olive oil from a store with a good turnover, and only buy olive oil in dark bottles or metal tins.
Some people refrigerate their olive oil to keep it extra-fresh, but this will turn it semisolid and make it difficult to pour from the bottle. If you don’t go through olive oil very quickly, simply buy smaller bottles of it.
How to Taste Olive Oil
How do you know if olive oil is good or not? It’s obvious, really: taste it. Here’s a tutorial from the Olive Oil Times if you want to do it the fancy way. Or you can stop in a store that offers olive oil tastings. They’re fun! Even so, it’s enlightening to taste the oil already in your kitchen. Pour about a tablespoon into a small glass. Swish it around and smell it. Hold it cupped in your hands to warm it up a little. Like wine, good olive oil can have a huge range of aromas: grassy, fruity, spicy, herbal. Look out for that old crayon smell—that means it’s rancid, and you should pitch it. Then sip some of the oil and swish it around your mouth. After a bit, swallow it. You may feel a peppery grip at the back of the throat. It can be intense, but this is a desirable sign, not a sign of a defect. Since most of us don’t do olive oil shots, the real purpose of this exercise is to simply get to know your house olive oil. Dip bread or a lettuce leaf in it to think more about how it tastes when you’re using it in recipes. If you don’t like what you’re tasting, try another brand. I stick to the same brand, but since there can be variances between batches, it never hurts to do an occasional quality control assessment to see if your go-to oil is still delivering the goods for you.
Why Olive Oil Is the Best Cooking Oil, Smoke Point be Damned
First, the good news: you can safely sauté and fry in olive oil! A smoke point is the temperature at which an oil begins to smoke, and if you cook very much at all, you have probably unintentionally heated oil to its smoke point. (Or, if you are searing a steak in a smoking-hot skillet, you have intentionally reached the smoke point.) You may have heard rumors about how olive oil’s smoke point isn’t high enough for cooking, baking, or other everyday uses. But since its smoke point is actually around 400°F, you can confidently use olive oil for almost all of your everyday cooking. What’s more, an oil’s smoke point does not necessarily correlate to its performance. Extra virgin olive oil has high levels of antioxidants and monounsaturated fats that help it stay stable under heat for longer periods of time than many other oils. (Coconut oil and avocado oil also performed well in studies.) Heating oil does change the way it tastes, so keep that in mind if you don’t want to waste a more expensive olive oil in a high-heat cooking method. But if you like how extra virgin olive oil is a more natural form of oil and you prefer to use that for sautéing and low-temperature deep frying, then go for it! It’s not dangerous. So, there you have it! The compounds naturally present in extra virgin olive oil make it a great choice for sautéing, roasting, and even frying. It can handle the heat!