Does Olive Oil Go Bad? How Long It Lasts and How to Store It

Short answer: yes, olive oil goes bad — but it doesn't spoil the way milk does. It oxidises slowly, losing flavour and polyphenols first and eventually turning rancid. An unopened bottle of extra virgin olive oil is at its best for about 12 to 18 months from harvest; once opened, use it within two to three months for full flavour, and within six months at most. Rancid olive oil won't make you ill, but it tastes stale and has lost most of what you paid for.

How to tell if olive oil has gone bad

• Smell it. Fresh extra virgin olive oil smells green, grassy, fruity or like fresh-cut tomato leaf. Rancid oil smells like crayons, putty, old nuts or stale peanuts.
• Taste it. Fresh oil is fruity with some bitterness and a peppery catch in the throat. Rancid oil is flat, waxy and greasy, sometimes with a metallic finish.
• Look at it. Colour tells you little — good oils range from deep green to pale gold — but cloudiness in a normally clear oil, or a sticky residue on the bottle neck, points to age.

What "best before" actually means

The date on an olive oil bottle is set by the bottler, typically 18 to 24 months after bottling, and it says nothing about when the olives were pressed. An oil can be bottled a year after harvest and still carry a two-year best-before date. That is why the harvest date matters more than the best-before date. Olives are pressed once a year, in the Northern Hemisphere from October to January, so an oil labelled with the most recent harvest is the freshest you can buy.

What makes olive oil go bad faster

Four things: light, heat, air and time. Light and heat drive oxidation directly. Air gets into the bottle every time you open it, which is why a half-empty bottle degrades faster than a full one. Extra virgin oil resists all of this better than refined oil because its polyphenols act as natural antioxidants — a high-polyphenol oil literally lasts longer. Our oil tested at 260 mg/kg; the more polyphenols, the more protection.

How to store olive oil so it lasts

1. Keep it in a cupboard, away from the stove, the window and the top of the fridge. Room temperature is fine; the enemy is warmth and light, not the absence of cold.
2. Keep the cap tight and put it back immediately after pouring.
3. Buy dark glass or a tin. Clear bottles look nice on a shelf and are the worst choice for the oil.
4. Buy the size you'll finish. A 500 ml bottle for a household that uses a little; a 3 L tin for one that cooks with it daily. If you buy a tin, decant a week's worth into a small bottle and keep the tin sealed.
5. Don't refrigerate for everyday use. Cold oil turns cloudy and thick (harmless, and it clears at room temperature), but repeated warming and cooling introduces condensation. The fridge only makes sense for a bottle you won't touch for months.

Can you use olive oil after the best-before date?

Usually, yes, if it has been stored well and it smells and tastes fine. The date is a quality guide, not a safety cutoff. Trust your nose: if it smells like crayons, use it for something other than food, and if it smells fresh, it is fresh.

Does unopened olive oil go bad?

Slowly. A sealed, dark bottle stored in a cool cupboard will stay good for roughly 18 months to two years from bottling, with flavour and polyphenols declining gradually throughout. It will not keep indefinitely, so olive oil is not a good thing to stockpile.

Frequently asked questions

Is cloudy olive oil bad?

Not by itself. Oil turns cloudy when it gets cold, and unfiltered oils are cloudy from the start. Cloudiness plus a rancid smell is age; cloudiness alone is temperature.

Can rancid olive oil make you sick?

It is very unlikely to cause illness in the amounts used in cooking, but it tastes unpleasant and the beneficial compounds are gone. There is no reason to eat it.

How long does olive oil last once opened?

Two to three months for the best flavour, up to six months if stored well. Write the date you opened it on the bottle.

Golden Spoon extra virgin olive oil is cold-pressed in Tunisia and shipped from Ottawa in dark bottles and sealed tins. Our current lab reports — including free acidity and peroxide value, the two chemical markers of freshness — are published on our lab analysis and certificates page. Browse the full range.