Does Olive Oil Go Bad? Yes, But Here’s How To Stop It

How much would you reasonably pay for a bottle of olive oil? £5, £10, £20? You could easily pick up a decent bottle with that budget.

But there are brands out there that are charging in excess of £100 for a bottle of what the ancient Greek author Homer describes as “liquid gold”.

I don’t know about you, but if I were paying that much money for a bottle of olive oil, I’d be saving that bad boy for when the King comes round. I wouldn’t be using it for my daily scrambled eggs or hummus, that’s for sure.

But olive oil, it isn’t like wine. It doesn’t get better with age.

If your question is: does olive oil go bad? The answer is a definitive yes. Olive oil begins to degrade from the moment it is bottled.

It has an expiry date, and its life isn’t very long at all. So, if you’re paying a hundred bob for olive oil, you want to make sure you’re using it, and you want to be quick about it as well.

Thankfully, though olive oil will inevitably go bad, there are a few things that you can do to slow down its degradation.

I don’t think it’s common knowledge in Northern Europe and the United States that extra virgin olive oil, like vegetable oils, has an expiry date.

Olive oil has a comparatively shorter shelf life than most other oils as it is derived from fruit rather than seeds, unlike many other vegetable oils.

The reason that it isn’t common knowledge, I think, is because even though olive oil has supposedly been consumed in the Mediterranean since the ancient Greeks, it was never really a thing outside these regions until fairly recently.

In Northern Europe and the United States, people have historically cooked with animal fat, which has a much longer shelf life than vegetable oil. It’s only since the introduction of the “Mediterranean diet” and the controversial recommendations by health authorities around the world to reduce saturated fat consumption that extra virgin olive oil, the supposed healthiest of all vegetable oils, became a staple across the Western world.

As such, we’re treating olive oil the same way as we have historically treated animal fat. But unforunately, olive oil just doesn’t last that long.

Although estimates may differ, generally an unopened bottle of olive oil can remain viable for up to 24 months under ideal storage conditions.

But once it’s opened and exposed to the air, it’ll go bad a lot faster. Again, estimates vary, but an open bottle of extra virgin olive oil can last anywhere between 12 to 20 months, depending on how it’s stored.

Though even if it lasts that long, it’ll still degrade gradually over time. So a one-year-old bottle of extra virgin olive oil, while still usable, wouldn’t be as fragrant nor as tasty as one that’s been freshly opened. Ideally, a bottle should be used up a lot sooner. Estimates vary once again, but you should ideally be using a bottle within one to two months or up to six months from opening. The common consensus is that past this point, the oil is well past its prime.

So, how do you know if your olive oil has turned bad?

The first port of call is the expiry date. If it has expired, toss it.

Another thing to check is the harvest date. Any decent bottle will have the date that the olives were harvested printed on it.

If the harvest was within the last two years, it may be okay. If it’s in date and the harvest was within the last two years, give it a little taste. Even if it’s off, it won’t make you sick or anything like that. It just won’t taste great.

If it does have a rancid taste, that is a bitter, sour, or stale flavour, bin it. A stale olive oil will have a crayon or putty-like smell. Again, if this is how it smells, get rid of it.

Though while you could still use it technically, a cooking fat is the bedrock of any given dish. If the olive oil tastes funky, it’s going to make your entire dish taste the same. So, probably not a great idea. Worse still, a degraded olive oil will have a lesser nutritional profile. That is, it’ll be less good for you.

How to make your olive oil last longer

The good news is you can actually slow this process down. There are four factors which will degrade your olive oil: oxygen, heat, light, and time.

Oxygen: The more the oil is exposed to the air, the more it oxidises and degrades. The best way to avoid this is to keep it sealed whenever you’re not using it.

Heat: The heat from your stove isn’t good for olive oil. Even though most people store their olive oil by the stove, it’s best to keep the oil as far away from the stovetop as possible.

Light: Ultraviolet rays from the sun will also degrade the oil, so it’s best to keep the oil away from windowsills or anything like that.

Time: No matter how well it’s stored, the olive oil will still naturally degrade over time. So, unless you’re that what’s-his-face kid with the stopwatch who can pause time, there’s really not much you can do here.

Some people suggest storing olive oil in the fridge to extend its life, but a recent study found that storing it in the fridge didn’t actually increase the longevity of the oil at all. It did, however, make it cloudy and three times more viscous.

All that being said, there’s nothing wrong with storing it in the fridge or even outside the cupboard. I store mine on top of my fridge, away from direct sunlight, and it seems okay so far. Maya Hershbein, an oleologist or an olive oil tasting expert at Cordo Olive, says you can even store the oil near the stove as long as a) you’ll get through the bottle reasonably quickly (within a month or two) or b) you store it in a cruet, which is like a ceramic jar that will protect it from the heat of the stovetop.

With all that in mind, to keep your oil fresh for as long as possible, here’s my suggestions:

1. Store it away from direct sunlight.
2. Store it in a cool, dark place, ideally around 14 to 18 degrees Celsius. In practice, this means storing it in a cupboard ideally, but failing that, in a fridge (remembering that the fridge will impact the olive oil’s viscosity). As a last resort, anywhere away from direct sunlight or heat, or if desired, stored near the stove (if stored in a cruet).
3. Keep it well sealed to avoid air exposure.

By following these measures, when asked, ‘does olive oil go bad?’ You can confidently answer, ‘yes, but not in my case.

One final thought: Does it make any difference which olive oil you buy?

I’d say yes, it does. Any decent bottle of extra virgin olive oil will have both the expiry date and the harvest date listed. If either are missing from the bottle, I’d recommend steering clear.

You may also want to consider buying in smaller portions if you’re not using that much oil. You definitely don’t want to be buying three-litre bottles of olive oil if you’re only using a drizzle now and again.

So, if you’ve been saving a fancy bottle of olive oil for a special occasion, stop faffing about. Crack it open and treat yourself to a shot.