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. 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,” says Savage. For chef Samuel McCandless of Arcana in Boulder, Colorado, the aroma is key. “It’s pretty easy to tell from the smell,” he says. “When it’s bad, it doesn’t smell fresh and fruity. If it smells waxy, like crayons, it’s gone.” 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. 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 food,” says Savage. “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.” “That said, it’s still safe to eat, and a better choice for human and environmental health compared to solid animal fats,” says Maggie Moon, M.S., R.D. 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. If your oil doesn’t come in a darkly tinted, opaque bottle—and it should—consider a fusti. These stylish stainless-steel containers are a great way to preserve olive oil, especially if you’re buying in bulk. Decant what you’ll use into the fusti, then keep the large bottle tightly sealed and stashed away until you need a refill.
