You may be left wondering whether olive oil goes bad after a while or if you can keep it around indefinitely. But you’ll be surprised to know that olive oil does expire.
The olive is considered a fruit. Fruits have a shelf life, and by extension, so does olive oil. There’s a point at which it goes rancid and simply doesn’t taste great.
Most olive oils last 18–24 months from the time they’re bottled. Extra virgin olive oils are less processed and usually last a bit less, around 12–18 months from the time they’re bottled (1).
Olive oils may develop acrid or bitter notes, which may show up in your cooking in ways you may not enjoy. Some olive oil bottles state a bottling or best-by date. If you don’t see these, it may be a good idea to tag your bottles with the date of purchase.
You should store olive oil in a cool, dark place — like a pantry with a door, a cabinet, or a refrigerator. If you store it in your refrigerator, it may look a bit cloudy. This is a normal reaction to cooler temperatures and does not indicate that your olive oil has gone rancid.
It also helps if the bottle is made from a darker glass, like dark green or amber, as this can help block out light, which promotes oxidation (2).
Oxidation is a cellular process that can stimulate aging. In olive oil, it can speed the breakdown of fat molecules. Besides light, olive oil can also be oxidized by contact with oxygen or exposure to heat. If your olive oil comes packaged in a plastic polyethylene container and you plan to keep it around for a while, it may be wise to transfer it to a dark glass or tin container (2).
The best way to tell whether your olive oil has gone rancid is by tasting it. Don’t worry, a small taste won’t make you sick. If your olive oil tastes bitter, sour, or stale, it’s no longer good. Bad olive oil may also smell off — like crayons, putty, or Elmer’s glue — instead of bright, fruity olives. Rancid olive oil won’t make you sick, however, the spoiled taste may ruin your recipe by giving the whole dish a strange flavor.