Yes, Olive Oil Can Go Bad

Olive oil is a pantry staple—most of us have at least one bottle in the cupboard or adorning the counter. Maybe you like to have a specialty bottle around, or it's the kind of thing you buy in bulk. Either way, the day may come when you find yourself gingerly sniffing an open bottle, trying to remember when you bought it, and wondering whether it's still usable. Spoiler: Olive oil can indeed, well, spoil. To keep your oil fresh and nutritious, plus avoid a rotten mishap, experts have some advice.

How long does it take for olive oil to go bad? Olive oil, when stored properly, has a shelf life of roughly 18 months.

We tend to forget, but olives are a fruit, and the pressed oil is likewise perishable. Virgin olive oil, which has a higher acid content, tends to last a little longer, with a shelf life of about 18 to 24 months from pressing. But as the least processed of all olive oils, extra virgin is your best bet. Not all olive oils are equal, and you'll enjoy the most health benefits—i.e., monounsaturated fatty acids, antioxidants, and anti-inflammatory agents—with extra virgin. Once you've opened a bottle of oil, however, the oxidation process picks up. The oil will begin to degrade relatively quickly, so you should ideally plan to use it within one to two months. How can you tell olive oil has gone bad?

Fresh olive oil has a singular quality and a dizzying range of delicate-to-intense flavor—fruity, grassy, floral, buttery, and on—with a slightly bitter, peppery, or pungent aftertaste. It has a thin texture, a pleasant aroma, and a bright freshness. Rancid olive oil, on the other hand, has none of these things. The flavor and scent of oxidization, is quite distinct. It has a very perceivable odor and taste that can be similar to old or stale peanuts. If you're having trouble going by scent alone, swirl a bit in your mouth. You'll know it's rancid if it's generally unpleasant and overly greasy. Can you use expired olive oil?

There's a difference between rancid olive oil and oil that's past its expiration date. If it still smells and tastes good, it's fine to use, though it may not be as bright as it was when you opened the bottle. Truly rancid olive oil won't hurt you, but it's not doing much for you either. Old or bad olive oil most certainly has a negative effect on a dish, especially when drizzling on foods. Extra-virgin olive oil is meant to enhance a food's flavor. With its green and often herbaceous flavor profile, it will only add to an existing flavor, whereas old oil can actually mask some flavors and brings no enhancement to food. The best guide here isn't necessarily the expiration date—which tells you nothing about the age of the oil or when you opened it—but your own nose and taste buds. Many reputable procurers also provide a harvest date on the bottle, which is a much better indicator of an oil's age. Moon notes olive oil is generally good for 12 to 20 months past its harvest date. Between the two, you should have no problem deciding if an oil has turned. The bottom line.

Olive oil does have a shelf life, but it's easy to tell when it has turned. If it smells or tastes off, you're probably holding a bottle of rancid olive oil. And remember—it should live in a cabinet, not on the counter or fridge. From there, you have about 60 days to enjoy your antioxidant-packed oil.