Does Vegetable Oil Go Bad

Unfortunately, It does go bad and it also has an expiration date. Moreover, the shelf life of the oils is based on how long it has been opened and what is the expiration date. Not only that but in the category of oils quality is also one of the most important aspects. Furthermore, in terms of its consumption, it is important to Research says oils have a variety of uses besides edible applications.

There is now increasing evidence that fatty acids play a crucial role in human nutrition that include therapeutic and prophylactic prevention of diseases, in growth and development of human embryo, brain function and provide protection against many serious diseases such as cardiovascular, inflammation etc. (Reference link 1)

So, don’t mistake the shelf life of the vegetable oil as indefinite. Since vegetable oil is used in making almost all of the dishes you make in your kitchen, it’s better to check the expiry date of the oil so that you don’t waste your time making a dish that tastes weird.

But, at the same time,  do not fully rely on the expiration date as it can sometimes go rancid before the mentioned date or when the date is near.  So, here comes some warning signs to consider,

Warning Signs That Your Vegetable Oil Has Gone Bad

does vegetable oil go bad

While cooking,  checking the expiration dates of the ingredients are necessary. In Particular,  you are using the oil which has been sitting in your pantry for a long time. Because, then there might be chances that the oil has expired or has gone bad. 

Honestly, speaking, I recognized these signs when I mistakenly used the oil in my cooking without checking it which resulted in indifferent soapy or very harsh taste. (warning 1)

And later, the real reason for this expiration was that I  left the oil bottle in a very moisty place and skipped to see the slight change in its colour to dark yellow (warning 2). So, be vigilant! Because, in such cases, there are high chances that it could  grow  molds  inside the bottle or you might notice cloudiness or some white substance floating inside,(warning 3)   which can be very harmful for consumption.

Furthermore, if you open the bottle and it doesn’t smell like the usual vegetable oil or gives off odour like chemical or metal (warning 4)then it is a sign that it has gone bad and you should discard it. 

When Does Open Vegetable Oil Go Bad? 

After opening the bottle if you’ve stored it right then it can’t go even for a year but if an opened bottle isn’t stored right then it can go rancid in less than 6 months. From my experience I noticed a drastic change in storage period and later I found out that is because once a bottle of oil is opened it gets access to fresh air which affects a lot on the vegetable oil. 

Tips To Store Opened Vegetable Oil 

My experience says storing a bottle of vegetable oil at room temperature is fine until and unless there is sunlight or any kind of strong direct light reaching it or simply just keep it in the pantry away from moisture.

Other experienced people say that storing the bottle in cold temperatures can also increase the shelf life. Avoid using plastic bottles for storing it instead use glass bottles or the air tight container to avoid air getting inside it to avoid oxidation.          

With that, let’s get it clear that vegetables are not the only oil used in our kitchen. Numerous oils have different and longer shelf life than vegetable oil as they are extracted from seeds, fruits, or other edible components.

And because of the various chemical components present in them, most of the cooking oils and vegetables are plant-based and the colour of those oils is yellow or transparent. So, store it well!

When Does Unopened Vegetable Oil Go Bad ?

Does Vegetable Oil Go Bad

Vegetable oils come with a shelf life of twelve or eighteen months but they sometimes get spoiled before the date because of poor storage condition or bad quality and if stored right then they might be able to retain for a month or two after the expiry date.

but as already mentioned that quality plays a major role here so sometimes poor quality can lead a bottle to go rancid way before its shelf life. But storing it in the right way may decrease the risk of it getting spoiled before the written date. 

Tips To Store Vegetable Oil 

To store an unopened bottle of vegetable oil keep it in a place away from light and moisture and make sure that to keep it away from heat sources like the kitchen appliances.  

Storing it in a refrigerator is also a good choice as it can keep it fresh especially during summer, it can cause a kind of haziness in oil but heat it before using to get rid of that cloudy appearance. Check whether that oil bottle is properly sealed to prevent it from oxidation. 

What Happens If You Use Expired Vegetable Oil ?

Using expired oil is not bad news; it will not affect your health but it can affect the dish you made. Good quality vegetable oil can be a relief as it really doesn’t expire on the mentioned expiry date. 

Edible vegetable oils are prone to quality deterioration through oxidation and microbial degradation resulting in nutritional loss and off-flavours. (Reference link 2)

But it would be better if you check before using the oil whether it has any symptoms of being spoiled, which you can check by above mentioned warning signs to save your day. And if it shows any symptoms it’s better to throw it than taking any kind of risk. Vegetable oil can even after expiration date can work fine until its there in your pantry for years.

Protip To Extend The Life Of Vegetable Oil

Well there are few important things to keep in mind while storing vegetable oil is that:

  • Keep it in a cool dark place.
  • Avoid places where there is moisture.
  • Seal it in an airtight container.


Q1. How long does vegetable oil last once opened?

Ans. Once opened it can go for 6 months or more if stored in a proper manner.

Q2. Can I use vegetable oil that expired 2 years ago?

Ans. Well there are few chances that you can use it if the bottle is not opened but if it was open and you found it after 2 years then you should probably discard it.

Q3. What does bad vegetable oil smell like?

Ans. A spoiled vegetable oil smells like metal, paint, chemicals or old crayons. It has very harsh and rough taste.

Reference link: 

1. Vegetable Oil: Nutritional and Industrial Perspective 

2. Assessment of quality of edible vegetable oils accessed in Gondar City, Northwest Ethiopia

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