Does Olive Oil Go Bad?

So you’ve bought a bottle of olive oil, used it once and put it in a cupboard only to forget about it minutes later. Next time you needed oil, you used the cooking oil instead. A year later, you found that bottle while cleaning up. It was an expensive bottle, so you would rather not throw it out. Does olive oil go bad?

Or maybe you received a bottle of high-quality EVOO as a birthday gift almost two years ago. It still sits in the pantry unused, and you start to wonder if it’s still good enough to use. It’s already nearing the date on the label, so you feel like time is running out and you need to either start using it right away or toss it out.

If you’re in a similar situation and would like to learn more about storage, shelf life, and going bad of olive oil, read on.

Bottle of olive oil

How To Store Olive Oil

Storing olive oil is no different from storing other oils, like canola or grapeseed oil. That means you should keep it in a cool and dark place, away from sunlight and sources of heat. The pantry or the cellar is the best choice for long term storage.

Once you open the bottle, remember to seal it tightly when not in use. Access to fresh air causes oxidation, and that results in the oil going rancid. The pantry isn’t the most practical place to store opened olive oil. That means you probably should keep it in a cupboard in the kitchen, so it’s within arm’s reach. Please note that all the requirements regarding storage conditions stay true for an opened bottle. So that cupboard shouldn’t be near the stove, and you definitely shouldn’t let the oil sit on the counter. In either case, the oil will degrade in quality within a few months.

There’s also the question of whether or not you should refrigerate EVOO. The best answer I can come up with is: refrigeration is not required, but it doesn’t hurt. Please note that olive oil will become cloudy when chilled in the fridge. That process is not harmful, and the consistency will get back to normal once the liquid reaches room temperature.

Olive oil in a dispenser bottle
(credit: jonathan ocampo)

Once more tip when it comes to storing EVOO. If you’ve bought a large container of olive oil, transfer some of the fat to a small dark bottle. You can keep that bottle in the kitchen, so it’s easy to grab it when needed. The large container should go to a dark and cool place, and you should open it only to refill your handy bottle. This way, the EVOO in the big container will retain its quality for much longer.

SummaryKeep olive oil in the cool and dark place, away from sources of heat. Once opened, make sure it’s always sealed.

How Long Does Olive Oil Last

Olive oil, like other oils, has a fairly long shelf life. For starters, each bottle comes with a best-by date, which is an estimate of how long, at the very least, the product will retain freshness. Of course, like with almost all products that come with a best-by date, the oil will remain at good quality for longer. That’s true provided that you follow the storage guidelines outlined earlier.

How long past the date on the label will the EVOO be good? It’s impossible to say, as it depends on both storage methods and the quality of the oil itself. So a more expensive bottle from a reputable brand will likely keep its freshness for longer. 3 to 6 months past the best-by date should be a reasonably safe estimate.

Adding olive oil to a salad
(credit: Jessica Lewis)

Once you open the bottle, the oxidation process speeds up a bit thanks to having access to fresh air. For best quality, you should try to finish the bottle within a year, but it should stay okay for up to 18 months.

Olive oil (unopened)Best by + 3 – 6 months
Olive oil (opened)12 – 18 months

Please note that all the periods above are estimates. Sometimes the oil will go rancid even quicker, other times it will stay fresh for even longer.

SummaryOlive oil retains quality for a couple of months past its date if you store it properly. Once you open the bottle, try to finish it within a year.

How To Tell If Olive Oil Is Bad?

Like other oils, olive oil usually doesn’t go bad in a way it’s unsafe to eat. Of course, if you notice any signs that make you question if it’s still edible, you should discard it. Such symptoms include the presence of mold near the seal, discoloration, change of consistency, or an off smell. As mentioned, these are highly unlikely to happen, but if either one of them happens, throw out the bottle.

What’s much more likely to happen is that the oil goes rancid. The first thing you should know is that rancid olive oil isn’t unsafe to eat. It’s only of worse quality. If you were to scour the Internet to learn about signs of rancid olive oil, you would find the answers are all over the place. Some people talk about a stale smell or taste; others point out subtle taste differences. Generally, it’s not that easy to tell the difference between rancid olive oil and a fresh one. The differences are quite subtle, and it’s often not clear if the oil is rancid or not. Especially if you never consumed fresh, high-quality EVOO.

What’s even more interesting is that many of us prefer the rancid version, as we’re more accustomed to the taste. If this phenomenon intrigues you, check out this article on FiveThirtyEight. In short, if you notice that your olive oil is rancid, it’s up to you whether you continue using it or discard it.

SummaryMore often than actually bad, olive oil goes rancid. If its smell is off, taste stale or somehow altered, chances are your bottle is rancid. It up to you if you discard it, or continue using it, though.

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