Olive oil can go bad, but the time frame for this depends on various factors, such as the quality of the oil and how it is stored. Generally, extra virgin olive oil lasts between 18 to 24 months, but it’s best to use it within six months of opening for optimal taste and benefits. Now, have a look at the warning signs before you use your olive oil for today’s meal!
5 Warning Signs That Your Olive Oil Gone Bad
The most common reason for the expiry of olive oil resides in the process of oxidation. In simple words, oxidation is the process of being exposed to oxygen resulting in the breakdown of fat molecules and thus turning the oil rancid. Oxidation primarily depends on the following factors including storage conditions, techniques of oil extraction and exposed degree of oxygen, light and temperature. (Reference 1)
Now grab a look at the following warning signs.
1. Rancid smell:
Olive oil that has gone bad may have a rancid or musty smell. This happens particularly due to the process of oxidation. In this process, certain carbonyl and aldehyde compounds get produced which lead to the development of off flavours and thus give rise to oxidative rancidity. (Reference 2)
2. Cloudy appearance:
If your olive oil has a cloudy appearance, it may have gone bad. Cloudiness can indicate that the oil has been contaminated with water or other substances, which can cause it to spoil.
3. Sediment at the bottom:
If you notice sediment at the bottom of your olive oil bottle, it may be a sign that the oil has started to break down. Sediment can indicate that the oil has been exposed to air or light, which can cause it to go rancid.
4. Sour taste:
If your olive oil has a sour taste, it may have gone bad. Sourness can be an indication of oxidation, which can happen when the oil is exposed to air, light, or heat for too long.
5. Lack of flavour:
Olive oil that has gone bad may lose its flavour or taste flat. This can happen if the oil has been stored for too long or has been exposed to air, light, or heat.
Tips To Store Olive Oil
1. Cool temperature:
Olive oil should be stored at a cool temperature, ideally between 57°F and 70°F (14°C and 21°C). Exposure to high temperatures can cause the oil to spoil, so avoid storing it near heat sources.
2. Dark place:
Olive oil should be stored in a dark place to protect it from light. UV light can cause the oil to break down and go rancid, so choose a dark cupboard or pantry for storage.
3. Airtight container:
Exposure to air can cause the oil to go rancid, so choose a container with a tight-fitting lid. Airtight containers ensure that the oil is not exposed to oxygen and hence check the process of oxidation and prevent it from turning rancid.
4. Away from heat:
Olive oil should be stored away from heat sources such as stovetops, ovens, or sunny windowsills. Exposure to heat can cause the oil to break down and lose its flavor and aroma.
5. Away from light:
Olive oil should be stored away from direct light, especially sunlight. Exposure to light contributes to the process of photo-oxidation which occurs through the action of photosensitizers and causes the oil to degrade and go rancid. So, storage and packing conditions play a primary role here.
Proper packaging ensures the longevity of the product by protecting it from oxygen and light. Olive oil is commonly stored in glass, tin or plastic containers, tin being the best one as it does not favour photo-oxidation (which occurs when oils are exposed to light). The inside of the tin containers is coated with resins which protect the metal surface from corrosion. (3)
The storage temperature, use of nitrogen atmosphere and reduction of oxygen in the headspace volume can positively influence the quality of olive oil. The optimum storage condition and the ideal container type for storing should be well-known in order to increase the shelf-life of the oil. (3)
What Happens If You Use Expired Olive Oil?
Using expired olive oil can have negative effects on both taste and health. Consuming rancid oil can cause digestive discomforts, such as nausea, vomiting, and diarrhoea. In addition, expired olive oil can lose its nutritional value and may contain harmful compounds that can contribute to inflammation and other health issues. It is best to discard expired oil and replace it with fresh oil for optimal taste and health benefits.
Factors That Cause Olive Oil To Go Bad
Exposure to oxygen, also known as oxidation, is one of the major factors that lead to the deterioration of the quality of olive oil. The process of autoxidation (oxidation that occurs in the absence of light) results in the formation of hydroperoxides which get further decomposed to produce a mixture of volatile compounds.
These compounds include aldehydes, ketones, hydrocarbons, alcohols and esters which lead to rancidity and break of the oil’s nutritional value. (Reference 3)
Exposure to light, especially UV light, can cause the oil to degrade and become rancid. Light can also affect the oil’s flavour and aroma. The shelf life of the oils that had been exposed to excessive artificial light and diffused daylight is shorter than the ones stored in the dark. (3)
The ideal temperature to store olive oil primarily ranges between 14-21 degree Celsius, hence cool temperature should be maintained for storing olive oil. Exposure to heat or rise in temperature can cause the oil to break down due to oxidative degradative reactions and lose its flavour, aroma, and nutritional value. Heat can also accelerate oxidation and cause the oil to become rancid.
Over time, even when stored properly, the oil can degrade and become rancid. The length of time the oil remains fresh varies based on factors such as the quality of the oil and the storage conditions.
For example, according to a study by NCBI, it has been concluded that chemlali olive oil can stored upto 6 months if packaged in dark glass or tin containers. If best packing and storage conditions are maintained, then the oil can be preserved for at least a minimum period of 180 days. (3)
Exposure to air, moisture, or other substances can contaminate the oil and cause it to spoil. Contamination can also introduce harmful bacteria, which can lead to food poisoning or other health issues.
Q1. Is olive oil still good after 2 years?
Ans. Most extra-virgin olive oil lasts between 18 and 24 months. It can still be safe to consume after 2 years, but its taste, nutritional value, and quality may have been significantly degraded.
Q2. When should you throw out olive oil?
Ans. Olive oil should be thrown out when it becomes rancid, has a sour smell or taste, or has been stored improperly for an extended period. Generally, olive oil lasts for 18 to 24 months, but this can vary based on storage conditions.
The article aims to provide accurate and authentic information for the benefit of the readers.
- Research gate: Shelf Life of Extra Virgin Olive Oil and Its Prediction Models
- NCBI: The effects of packaging and storage temperature on the shelf-life of extra virgin olive oil
- NCBI: Effects of containers on the quality of chemlali olive oil
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