Does Olive Oil Go Bad? What Can You Do About It?

Olive oil is, without a doubt, one of the most common and popular healthy fats that we include in the diet.

The oil is particularly prevalent in the Mediterranean diet but is also present in many different eating and lifestyle practices. A key reason is that the oil is simply so healthy.

For example, the health benefits of olive oil include the potential to reduce inflammation (1,2,3), to lower blood sugar levels (4), improve cholesterol profile (5,6,7), decrease blood pressure, to act as a powerful source of antioxidants (8,9) and to potentially help fight cancer through the action of the compound oleocanthal (10).

So then, it’s no surprise that the oil is so prevalent. But, does olive oil go bad? And, if so, what can you do about it?

After all, olive oil is relatively expensive, especially when you compare it to unhealthy alternatives like canola oil. Likewise, it’s important to choose a high-quality olive oil brand and to focus on extra virgin olive oil – factors that can also add to the price.

Now, the health and the taste benefits of olive oil make it worth the cost. But, you do want to get the most out of your oil, which is where this discussion comes in.

Does Olive Oil Go Bad?

At some point or another, all natural food (with the exception of honey) will go bad. How fast this happens will depend on a range of factors, including the quality of the olive oil, when it was harvested and how it is stored.

The term used to describe this process is olive oil going rancid. Now, as Livestrong highlights, rancid olive oil won’t typically make you sick, especially not in the short-term. However, there is the risk of long-term negative effects due to the production of free radicals. 

At the same time, rancid oil simply doesn’t taste as good and won’t offer the same health benefits as regular olive oil. These aspects alone make it important to detect and prevent olive oil rancidity.

After all, the key reason for consuming olive oil regularly is health benefits. Consuming rancid oil won't offer those same advantages and could even put your health ​at risk - so it simply isn't worth doing so.

How Long Does Olive Oil Last?

As a general rule, olive oil is considered good when it is within two years (24 months) of its initial bottle date. But, this is only an approximation. Instead, the shelf life of olive oil can vary based on a range of factors, including the olives used, the specific brand and other factors.

One of the most reliable estimates for the shelf life of olive oil is the best by date provided. This date is calculated by the manufacturer, who has the most knowledge about how long the oil is likely to last under optimal conditions.

Some people do suggest that you should instead look at the bottled or the harvest date and calculate how long the olive oil should last from there. But, such an approach ignores the complexities of different olive oils, along with the experience of the company producing it.

Additionally, the harvest date may be particularly irrelevant because olives are a seasonal fruit. As such, olives will typically be harvested from October to December each year. So, if you're buying olive oil in March or April, the harvest date will never be that recent.

Different varieties of olives also vary in how long they keep for -  which is another reason for trusting the date that the manufacturer provides. 

Now, this length of time generally refers to the sealed olive oil. Once opened, most recommendations suggest that you consume the olive oil within a few months - so choose your bottle size with this in mind.​

In theory, reliable brands and high-quality olive oil should last longer. If nothing else, good brands will often have the harvest date, while poor-quality ones may not. That information gives you a better indication of how long your olive oil is likely to last.

Nevertheless, determining the quality of olive oil is difficult to judge, especially as some inexpensive brands end up being better than expensive alternatives - and the reverse is also true. As a result, relying on lists of best olive oil brands is a good place to start, along with your personal experiences​.

How to Tell if Olive Oil is Bad

Olive oil rancidity is fairly easy to spot but only if you know what you’re looking for. In fact, many people end up regularly consuming rancid olive oil because they don’t know how to tell the difference.

Here are some of the key indications.

Color: Swirl the olive oil and closely look at the color. Olive oil will typically become a brighter yellow when it is going rancid. However, be aware of initial differences – as the color of olive oil can vary significantly.

Scent: When olive oil is fresh, it tends to have a pungent and fruity smell. In contrast, rancid oil often has little scent and is often thought to smell similar to stale peanuts or crayons. Some people also find that rancid olive oil smells excessively sweet.

Again, it’s important to compare this to how the olive oil was initially, as the aroma of brands and harvests can differ. Extra virgin olive oil does also have a natural sweetness and it’s easy to mistake this for rancidity.

Good olive oil should, and does, smell like fresh olives. Unfortunately, bad olive oil is so common nowadays that many people have never experienced this.

Taste: Rancid olive oil typically has a bitter taste with little to no fruitiness and can also taste a little like pumpkin.

Additionally, fresh extra virgin olive oil​ should create a burn at the back of your throat when you swallow it. This is because of the compound oleocanthal, which has some antioxidant and anti-inflammatory properties (11).

Texture: In many cases, rancid olive oil will feel greasy, especially in your mouth. Because of this, you can test both taste and texture at once by rolling a little olive oil around in your mouth (don’t worry, even if the oil is rancid, it won’t harm you).

Beyond these areas, it’s also best to discard olive oil if it seems ‘off’ in any other way. For example, olive oil will sometimes end up smelling musty, especially if the olives were moldy. Likewise, olive oil may end up with a vinegar-like flavor, which isn’t desirable either.

In most cases, the greasy feel in the mouth will be the first thing that you notice, followed by the scent.

When it comes to determining olive oil freshness, be aware that rancidity is a scale. As you become more experienced at knowing the signs that olive oil has gone bad, you should be able to detect the issues earlier.

For example, the site Olive Oil Times suggests that on a scale of 1 to 10, most people will notice olive oil rancidity at a 9 or 10. But, the real trick is learning to detect it earlier, such as at a 5, 3 or even lower still.

Stopping Olive Oil from Going Bad

You cannot entirely stop olive oil from going bad but you can slow down the process.

Specifically, olive oil is impacted by air, light, heat and time. Influencing these areas can help make sure that your olive oil lasts as long as possible. So, let’s take a look at them:

Accounting for the Time Factor

Paying close attention to dates can help ensure you get the best shelf life from your olive oil. Ideally, you want a product that states the harvest dates and that date should be close to when you are buying it (as much as is feasible).

Because olive oil goes bad, it’s also worth paying attention to when you open it and how many bottles you have open at once. You might even choose to write that date on the bottle.

One of the best ways to get around rancidity is to simply use your olive oil up fast enough. For example, some people aim to keep their oil around for no more than three months. This lets you use the oil at its best, with little risk that it will go rancid.

To do so, you can choose the size of bottle based on how much oil you use. So, if you heavily rely on olive oil in the kitchen, a large bottle may be fine. If you don’t – stick to smaller bottles.

Protecting from Heat and Light

There are two main ways to decrease how much light olive oil is exposed to. The first is simply where you store the oil. The ideal is a cool, dark place that is out of direct sunlight.

You can also store the olive oil in the fridge, which can significantly increase its longevity. Some olive oil may become cloudy when you do so or could even solidify.

That process isn’t unhealthy and isn’t an indication that the olive oil is poor quality. Instead, olive oil is a type of fat, so it’s hardly surprising that it can solidify. If and when it does is strongly dependent on the chemical composition and this varies across brands and harvests.

The end result is that storing olive oil in the fridge is healthy and it should return to normal at room temperature.

Nevertheless, many people prefer keeping olive oil at room temperature, as this can give a better flavor profile and makes it easier to use. If nothing else, keeping the oil in a cupboard means that you're minimizing temperature swings. 

By doing so, you may be able to ensure the ​best possible taste and benefits from the olive oil. Keeping olive oil at room temperature is also more convenient, as you don't need to warm it up again. 

More information about this balance can be found at the site The Passionate Olive, which also offers insight into how to get the most out of your olive oil.

There is an exception though. If you live in a hot climate, then you may need to store olive oil in the fridge instead, as high temperatures can cause significant decreases in the active compounds in olive oil (12).​

The second approach for avoiding light and heat is what the olive oil is stored in.

In most cases, people simply keep olive oil in its original bottle (or can). However, many olive oil bottles are relatively transparent, making it easy for the light to get in.

This may not be an issue if you only ever take olive oil out when you plan to use it and put it back in a dark place immediately afterward. But, if you want to have it on a table or need to use it frequently, storing it in a light blocking bottle makes more sense.

Some olive oil will even come in bottles that block out the light and a few brands are in a can, which also have this effect. But, if the olive oil comes in a transparent bottle, you can always transfer it to a dark bottle of some type.

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There are also various other types of bottles, such as ones that are ceramic and designed to prevent any exposure to light. Likewise, stainless steel bottles are sometimes recommended as a particularly effective alternative. So, you can shop around to find an option that works for you.

Protecting Against Air

The final important area is reducing air exposure. This is critical because many olive oil bottles have caps that don’t screw back on easily. Even if the bottle does reseal without an issue – you’re still exposing the olive oil to significant air with each use.

Olive oil pourers are a key way around this.

These work like the name suggests, allowing you to pour olive oil directly from the bottle. Even the best olive oil pourer won’t entirely keep air out but you do expose the oil to much less air than you would otherwise.

The product below is a simple example of this type of approach. These pourers are designed to fit 16 oz. bottles and should work well for many different brands. You could also buy bottles to fit them and then transfer the olive oil to those bottles.

One useful feature here is the ability to entirely close the dispenser. Some brands of olive oil pourer will have this feature, others won’t. But, the ones that do are best for ensuring your olive oil lasts.

A second option is the example below. In this case, you get the pourer and a dark-tinted bottle, so there should be no issues about whether or not the pourer will fit properly. The pourer design isn’t quite as elegant but it would work well and does have the same ability to cap the nozzle when it isn’t in use.

Additionally, you do have a pourer and a regular cap for the bottle. As such, you can use the cap for storage and the pourer for dispensing, if you wanted to. Doing so is much better than having to rely on the cap of a store-bought olive oil bottle, especially as those aren’t always airtight.

A final example is the product below.

In this case, you’re looking at an all-in-one product, rather than a separate dispenser and bottle. This could actually be used for any type of oil (or vinegar) and isn’t specifically designed for olive oil.

The key advantage is that this bottle allows you to accurately measure olive oil quickly and without issue. Being able to do so is perfect for cooking, especially if you’re using olive oil in recipes.

The main limitation with this option is the glass, which isn’t tinted at all. As a result, the bottle would let in more light. However, if you’re not keeping the olive oil on the counter for hours at a time, the difference shouldn’t be a significant issue. In fact, the design should allow you to put the oil away faster, simply because this is so efficient.

There are other olive oil pourers out there too but these examples are all effective ways to get started. Regardless of what you choose, they can all be a good way to make your olive oil last longer.

Final Thoughts

The health benefits of olive oil make it a powerful addition to your diet and your kitchen. But, if you’re going to invest in olive oil, finding good brands is an important step, as is ensuring that your olive oil lasts as long as possible.

Storing it in a cool dark place and reducing exposure to light and air are both key ways to do this. Using an olive oil pourer is effective as well, especially when combined with dark glass, stainless steel or ceramic bottle.