How Long Does Olive Oil Last Once Opened? Plus: How to Store for Top Shelf Life

High in antioxidants and healthy fats, olive oil is a healthy and popular option for cooks around the world. Whether you are preparing pasta, fish or beef, a bit of olive oil is perfect for a wide variety of culinary applications, but how long will that bottle sitting next to the stove last?

Olive oil can last for more than a year once opened if properly stored. While an open bottle of olive oil can last up to 18 months, it is usually recommended that you use it within 60 days as there are a number of important factors that contribute to the shelf life of this valuable ingredient.

In this article, we will discuss how to properly store your olive oil in order to extend its life, whether or not consuming old oil can make you sick and how to dispose of your used olive oil. If you’ve ever wondered just how long your olive oil will last, read on.

How to Keep Your Olive Oil Fresh

Storage

The most important factor that contributes to the shelf life of your olive oil is the way it is stored. Heat, light, and air are the biggest enemies of freshness when it comes to olive oil, so you should always take care to keep your bottle in a cool, dry place away from direct sunlight whenever possible.

Keeping your olive oil in the pantry or cellar is optimal, although once opened, it doesn’t make much sense to run down to the cellar every time you’re cooking dinner. Once open, find a cabinet in your kitchen that isn’t exposed to light.

Also, since heat is a major factor contributing to the rate at which olive oil spoils, make sure the cabinet you store your bottle in isn’t located above the stove or near any other heating element.

Air Exposure

You should also limit the amount of time your olive oil is exposed to air. This means, don’t leave it on the counter with the cap off while you are cooking. Instead, add the desired amount to a pan or dish and immediately put the lid back on and return the bottle to its storage location inside a cabinet.

Some people prefer to buy certain items in bulk, and for those that love the taste and consistency provided by olive oil and cook with it regularly, this can be a good option.

However, if you do choose to buy a large container, you should fill a smaller, dark glass bottle for everyday use that can be kept in the kitchen. The larger, source container should be kept in the pantry or cellar with an airtight lid that is only opened when refilling the smaller bottle.

Quality of the Oil

The quality of olive oil can also influence its shelf life. Higher quality, extra virgin olive oil typically has more natural antioxidants that provide health benefits and slow the oxidation process that leads to oil going bad. Take note, besides just being less delicious, lower-quality oils also have a tendency to spoil faster than high-quality varieties.

Is It OK to Use Expired Olive Oil?

The date you see on a bottle of olive oil is generally a “best-by” date, meaning that it is more of a guideline intended to give you an idea about how old the bottle is and when the contents will no longer have their optimal flavor. Many olive oil producers also place a harvest or bottling date that can allow you to figure out just how old your olive oil is.

Once again, these dates are used to help you determine the freshness of your oil, but as long as it hasn’t gone bad–rancid–there is no reason to throw out a bottle just because it has passed the best-by date.

How Do You Know if Your Olive Oil Has Gone Bad?

If the expiration date isn’t an accurate indicator of whether your olive oil is still good, what is?

We now know that olive oil has quite the shelf life, but it will eventually go bad, and the easiest way to know if your oil is rancid is to give it a sniff. Pour out a small bit of oil into the cap; if it smells sickly sweet–think fermenting or rotting fruit–then your olive oil’s time has come.

However, olive oil doesn’t go bad overnight. Instead, it slowly becomes more rancid as it oxidizes, and the flavor changes. The oxidation that leads to rancidness is due to a series of chemical reactions between fatty acids, and there are two different types of processes that cause olive oil to go bad:

Auto-oxidation. This process takes place in the presence of air and is characterized by the reactions occurring between “free radical” oxygen molecules and the fatty acids in the oil. The natural antioxidants in the oil temporarily slow this process, but once all of these are depleted, the oil will oxidize quickly. This is an inevitable process, and there is nothing to be done to stop auto-oxidation of olive oil.

Photo-oxidation. This is the process of oxidation that occurs thanks to the presence of light and oxygen and, as we have discussed, can be slowed by reducing contact with these two factors by practicing proper storage methods.

Can Old Olive Oil Make You Sick?

As we know, olive oil most certainly goes bad; however, eating rancid olive oil will not make you sick in the way that eating rotten meat does. While it may not make you sick, rancid olive oil will not retain the healthy characteristics of fresh oil, namely the loss of the antioxidants that are consumed during the process of oxidation.

In fact, historically, consuming rancid olive oil was common around the world as the storage of these products was far less regulated, with many producers storing oil in open lidded, earthenware pots. Basically, consuming old oil isn’t necessarily the end of the world.

Since rancidness is on a continuum, many people actually prefer slightly rancid olive oil, as this reduces the bitterness that is a characteristic of some high-quality, varieties of fresh olive oil. This is especially true in the United States, where the regulation of olive oil lacks compared to other countries in Europe.

According to sensory scientist Sue Langstaff, “We call the U.S. the world’s dumping ground for rancid and defective olive oil. We don’t know the difference.”

Another reason that many people believe that Americans prefer slightly rancid olive oil is because it is what we have grown up with and have gained a preference for this slightly “off” flavor.

How Long Does Olive Oil Last in the Fridge?

Regardless of whether the olive oil you buy is 100% extra virgin, or another lower quality variety, everyone wants to get the most out of their food. As we discussed, proper storage is essential to extending your olive oil’s shelf life.

If keeping olive oil in a cool, dry, and dark place is the key to longevity, then why not keep it in the refrigerator? While it may help extend your olive oil life slightly, it is not the perfect answer that it may seem to be.

In theory, this may seem like the solution to the problem; however, some issues arise when storing olive oil at such low temperatures. The most dramatic is the change in the consistency of the oil. As the olive oil cools, the fats and fatty acids reach their freezing points and solidify.

Many of the fats found in olive oil also tend to turn cloudy as they freeze, and this opaque quality will be visible in your bottle of cooking oil.

How to Properly Dispose of Old Olive Oil

Once you’ve determined that your olive oil is no longer suitable to cook with, what do you do with it?

While it may seem like dumping it down the drain is the easiest answer, this is the absolute last thing you should do with oil of any kind, and this goes for olive oil that has already been used for cooking with as well. Instead, it’s best to pour spent oil into a container that can be properly disposed of later as cooking oil is one of the most common causes for clogged kitchen drains.

There are a few different options for disposing of old or used olive oil, the easiest of which is to throw into the garbage where it will be sent to a landfill. Since, unlike some other oils, olive oil stays liquid at room temperature, it is best to place it into a sealed container like an old soda bottle or the original bottle itself, to prevent any messes while throwing it away.

Most restaurants utilize some type of oil recycling service, and if you speak with the owner, they may be willing to take your used or spoiled oil and send it along with their regular pickup.

Finally, for those with gardens that produce their own compost, olive oil can be added to compost piles to be disposed of naturally. However, it should be noted that only small amounts of olive oil should be added to compost piles, as too much can slow the natural decomposition of other biological material.

Conclusion

Far from the eternal elixir that many people treat it as, olive oil most certainly has an expiration date, although it may not be printed on the side of the bottle. So, now that you know a bit more about what causes olive oil to go bad and how to store this delicious cooking implement properly, it may be time to take a whiff of that dusty bottle sitting on your shelf and see if it is past its prime.

Other Sources:

https://www.sun-sentinel.com/news/fl-xpm-2006-05-25-0605230208-story.html
https://www.racq.com.au/Living/Articles/How-to-dispose-of-olive-oil