Can vegetable oil go bad?

In this brief guide, we are going to answer the question “can vegetable oil go bad?” by providing answers related to the shelf life of vegetable oil, how long it lasts, how to identify stale vegetable oil and how to store it correctly  

Can vegetable oil go bad?

Yes, vegetable oil can go bad. It is an oil derived from the seeds of plants and we are aware that plants and their components or parts are perishable. Oil is prone to oxidation and rancidity. Both open and unopened bottles of vegetable oil can eventually go bad. 

An unopened bottle of oil will have a longer shelf life compared to an opened bottle. Let’s discuss this further and understand their shelf life and storage. 

How long does vegetable oil last?

An unopened bottle of vegetable oil lasts for over two years. We are all guilty of stocking up on a few bottles of vegetable oil. It is a common practice in households and it is should not be done. 

When you open vegetable oil, the shelf life reduces. The reason is that when you open a bottle of vegetable oil, it gets exposed to air and light. Oils in general, are prone to oxidation and this reduces the quality. Even though the quality does not deteriorate immediately, it happens over time. Hence, the shelf life of an opened vegetable oil is around 12 months. 

Always buy one bottle of vegetable oil at a time so that whenever you use it, it is at its peak quality. We all want our food to taste the best, so it is not a good idea to compromise on its quality.

How to tell if your vegetable oil has gone bad?

So all vegetable oils come with a best-by date. This date helps you judge the quality of the oil and it is usually not a determining factor when it comes to the safety of the vegetable oil. 

As the days pass by, the quality deteriorates. The longer you keep it lying around, the more oxidation will take place. There are three ways that can help you determine if it has gone bad-

  • When you have doubts about a certain food item going bad we need to rely on our senses to give us a definitive answer. Smell the vegetable oil and if it does not smell like how it did when you bought it, it has probably gone bad due to oxidation
  • Be aware of how the oil looked the first day you opened it versus the day you had doubts about it. If it has become dark, it has gone bad. 
  • Lastly, if you are still unsure about its quality, taste it. It will certainly taste not taste the same. This odd taste is an indicator.

Other FAQs about Oils which you may be interested in.

How to clean olive oil off the tile floor?

Can you get sick from eating rancid vegetable oil?

No, you do not necessarily get sick from eating rancid vegetable oil. The quality will be bad and it will not be worth keeping in your pantry but that does not mean that it is unsafe. 

It does not cause any harmful effects short term. If you feel like you have consumed rancid vegetable oil, it is not a cause of concern and you will not see any side effects. It will mostly just taste unpalatable which will make you want to throw it away.

But with that, it is a given that anything that has lost its quality should not be consumed. It is still a risk and if it has evidently gone bad, it must be discarded. 

What are the health hazards of rancid vegetable oil?

The long term effects of consuming rancid vegetable oil is cellular damage. Research showed that rancid vegetable oil goes through oxidation and the free radicals formed can cause side effects if consumed. 

Free radicals can lead to Alzheimers and it could also cause cancer according to a research article. It could also cause problems in your digestive system. 

If you accidentally consumed it, eat fruits and vegetables since they can prevent cellular damage 

How do you store vegetable oil?

To ensure that the vegetable oil lasts for a long time, store it in a cool, dry and dark place. It is important to store it away from the stove because constant exposure to heat can affect the quality of the oil. 

If stored efficiently, it can last for 2 years. Just be mindful and if you have doubts it is best to throw it away. 

In this brief guide, we answered the question “can vegans drink tea?” “can vegetable oil go bad?” by providing answers related to the shelf life of vegetable oil, how long it lasts, how to identify stale vegetable oil and how to store it correctly.

If you have any comments or questions please let us know.


Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.