How To Tell if Your Olive Oil Has Gone Bad, According to an Expert

Whether I'm roasting vegetables, pan-frying a piece of fish, or whisking together a salad dressing, nearly everything I cook uses olive oil. That means for me—and countless others—a spoiled bottle can abruptly halt cooking plans.

Is there a way to tell if your olive oil has gone bad? I recently spoke with Mary Mori, vice president of quality and product at California Olive Ranch, about how to assess whether your bottle has gone bad. "Sensory is key," she says.  

Is It Time To Toss Your Olive Oil?

Scent and taste are essential to identifying whether olive oil is still good. "Rancid oil will smell and taste like crayons, Play-Doh, Band-Aids, or stale nuts," Mori explains. "This is surprisingly much easier for people to recognize than they think."

You won't be able to tell the status of your olive oil based on how it looks, Mori warns, noting that it gets its color from the plant's chlorophyll, which is unrelated to taste. She goes on to say that texture is also an unreliable clue. "Some people may describe a rancid oil as 'greasy,' which really means it feels thinner than normal," she explains. "This isn't always easy to pick up and is not always tied to bad oils. Some defective oils won't have this texture."

Ways To Prevent Olive Oil From Spoiling

• Pay attention to the harvest date. Buy the freshest olive oil possible—check the harvest date on the bottle to ensure it's less than 2 years old. "Oils from southern hemisphere countries (Argentina, Chile, Australia) are typically harvested April through July, while oils from the northern hemisphere (California, Italy, Spain) are harvested October through January. Look for fresher harvest oils in the months following those seasons," Mori says.
• Buy the right size for your needs. "You shouldn't use the same bottle for more than two to three months," Mori cautions. "If you can't finish the amount you purchase in that time frame, buy a smaller container."
• Choose the correct container: To protect from light damage, opt for oil containers made from dark-colored glass or plastic. Try to avoid exposing the oil to as little oxygen as possible, which means using cork or stoppers, or switching the cap to a pourable spout.
• Be mindful of heat: "Keep the oil away from direct heat," warns Mori. "Being too close to the stove, where heat radiates often, will slowly degrade the oil."

Can't get enough olive oil talk? Read Mori's tips on how to properly store olive oil and learn the difference between extra-virgin olive oil and regular olive oil.