Oil is definitely a kitchen essential that we can never run out. If you’re into deep-fried stuff, keeping some packs of vegetable oil is such a lifesaver. You never know when the craving strikes, right?
It is also common to have several opened vegetable oils at the same time—canola oil for deep-frying, olive oil for salad, sesame oil for any Asian dishes, and many others.
Until it comes the cleaning day and you find a bottle of oil that has passed the best by date. No other thing matters than to know whether oil goes bad. Throwing away food supply is always frustrating.
If you often find yourself in a similar situation above, stay here. You’re about to find out the most essential knowledge on vegetable oil’s shelf life, its storage, and how to tell if vegetable oil has gone off. Sounds interesting? Read on!
How To Store Cooking Oil
Before we get down to the practicality, let’s talk about the general info on vegetable oil.
Vegetable oil refers to any kind of oil extracted from edible plants, mostly seeds, and fruits. Most common oils from plant seeds are canola oil, sesame oil, sunflower oil, corn oil, grapeseed oil, etc.
Meanwhile, oils extracted from other parts of fruits include olive oil, coconut oil, palm oil, avocado oil, soybean oil, etc.
In America, vegetable oil products are mostly soybean oil or a mix of some different oils.
As you probably have known, oil is susceptible to getting rancid. Proper storage conditions are crucial to slow down the oxidation that leads to the rancidification process. It means to keep oil safe from exposure to air, light, and moisture.
A cool, dry, dark place, out of heat and sunlight, is the perfect place for oil storage. Hence, not anywhere near the oven, stove, window, or microwave. Your pantry is highly preferred. But if you use oil more frequently, a kitchen cupboard or cabinet works well too.
After opening, always tightly close the container. If the cap is broken, transfer the oil into another bottle or jar.
Do you need to refrigerate vegetable oil after opening?
Generally, vegetable oil is a shelf-stable product that doesn’t require refrigeration. For certain types of oil, such as coconut oil, refrigeration is not recommended. Cold temperature solidifies the oil and makes it more difficult to use (or at least takes more time).
For some other oils such as sesame oil, refrigeration is suggested to keep it fresh longer. It may turn cloudy but doesn’t affect the flavor or taste.
How To Tell If Vegetable Oil Is Bad
Just like any other food, vegetable oil also goes off. But, since oil is already a self-preserving food, it doesn’t spoil quickly and not similarly like dairy or fruits. Still, proper storage is necessary to preserve the quality and shelf life.
As mentioned earlier, oil is prone to getting rancid. That’s the first sign we need to observe if vegetable oil is still good or not. You won’t get sick from eating foods prepared with rancid oil, but you won’t be pleased with the taste.
For many people, it is not always easy to tell if the oil has become rancid. For some oils, such as coconut oil, the spoilage signs are more visible and easier to observe.
The rule of thumb is if you notice anything off, either the smell, color, or taste, better to avoid using the oil. Anything that seems different from the first time you open the container deserves a second look.
Although this is highly unlikely, if you spot molds or other impurities, better to discard any leftover.
If you are not sure but still want to use the oil, consider using it for cooking instead of using it for salad dressing. The change in flavor is more noticeable when used in raw dishes like salad.
How Long Does Vegetable Oil Last?
Generally, vegetable oils last for 12 to 36 months, the shelf life varies among types and extraction methods (unrefined, refined, cold-pressed, etc.). This time frame is indicated by a “best-by” or “best before” date stamped on the package.
With proper storage conditions, you can expect that the oil will stay fresh until this time and possibly longer. Unopened bottles are likely edible for the next several months to a year after the recommended date, subject to perfect packaging.
After opening, the oxidation process happens faster, particularly with exposure to air and heat. It is suggested to use vegetable oil within 6 to 12 months. This time frame can be shorter for oils that are more prone to quality degradation, such as olive oil and sesame oil.
Best by date + 6 to 12 months if unopened or 6 to 12 months if opened
–
Unopened olive oil
best by date + 3 to 6 months
–
Opened olive oil
3 to 6 months
–
Unopened coconut oil
Best by date + 3 to 6 months
–
Opened coconut oil
6 to 12 months
–
Unopened sesame oil
Best by date + 6 to 12 months
–
Opened sesame oil
6 months
6 to 12 months
This table is a rough estimate. The actual shelf life generally depends on the types of oil, preparation methods, and storage conditions. If you happen to have old or expired oil that still looks fine, it’s worth spending a few minutes checking in case it’s rancid or spoiled.
FAQs
What are substitutes for vegetable oil?
That depends on how you want to use the oil. In general, vegetable oils can replace each other if they have similar properties. For example, for deep frying, you should pick oils with a higher smoke point, such as canola oil, sunflower oil, or corn oil.
What is the difference between refined and unrefined oil?
Unrefined and refined oil differ in the extraction method. Unrefined oil (also typically marketed as virgin or cold-pressed oil) is minimally processed at a lower temperature. It is also considered as the highest grade.
Refined oil undergoes more stages during the production, including refining, bleaching, and deodorizing (RBD) to remove any impurities and obtain more neutral flavor and odor.
Is vegetable oil healthy?
Vegetable oils are generally considered a healthy source of fats, except for hydrogenated oils that are typically high in trans-fat.
However, the high amount of polyunsaturated omega-6 fats in certain oils is another health concern. Olive oil is your best option for vegetable oil that is healthy and low in omega-6.
Final Thoughts
Vegetable oil is a kitchen staple, and like most foods, it goes bad. Going rancid is what you need to anticipate with this plant-based oil.
The ideal storage is a cool, dry, dark place, away from heat and sunlight. Proper storage will slow down vegetable oil from going rancid. But, if a noticeable change in smell, taste, and appearance is spotted, it is always better to stay on the safe side.
Rosa graduated with a master degree in Food Safety from Wageningen University and Research, The Netherlands. Recently, she started a consulting agency to facilitate the improvement of food safety, quality, and sustainability.
