Vegetable oil is a staple in every kitchen.
If you’re using it every day, you might be tempted to fill up your pantry with a dozen bottles. But before you do that, you should know the answer to a simple question – does vegetable oil go bad?
You’ve come to the right place to find the answer.
And not just that.
In this article, we’ll also talk about the storage and shelf life of vegetable oil.
Keep reading to learn more!
How Long Does Vegetable Oil Last?
Before we get into details, let’s make clear what vegetable oil is.
The term is used for any oil originating from a plant. So even though we wouldn’t call a sunflower a veggie, the sunflower seed oil is, indeed, a vegetable oil.
As you know, there are different types of vegetable oil. But in most cases, they have the same shelf life, which is about two years for an unopened bottle.
Once you pop the bottle open, the shelf life is somewhat shorter – about a year or so.
| Shelf Life | Unopened | Opened |
| Vegetable Oil | ~2 years | ~1 year |
Now, there are some vegetable oils that are more delicate than the others. These include sesame, corn, and different nut oils. Their shelf life is about a year when unopened. Once opened, they’ll last you anywhere from four to 9 months.
Still, you should be aware that vegetable oil goes rancid in time. So even though it might not get spoiled after some period, its odor and flavor might be too strong to be used.
As to when it will become too rancid to be used, there’s no single answer. It depends on how you store it. We’ll get into it in the next few sections.
How To Tell If Vegetable Oil Is Bad
Vegetable oil doesn’t get spoiled in the traditional sense of the word. You won’t usually see mold growing on the surface.
But what will happen is it will go rancid after some time. Rancidity is an oxidation process of oils and fats when exposed to air, light, and moisture. Rancid oil will become dark in color and develop a strong, unpleasant smell.
Fresh vegetable oil smells rather neutrally. But when gone rancid, you’ll notice it has a strong chemical odor, somewhat like old paint.
You know how oil can become dark after an hour of cooking? What happened is it went rancid from being exposed to too much heat and air. Well, that’s also what happens when stored for too long.
While rancid vegetable oil won’t get you food poisoning, it can be damaging when consumed often.
Finally, you might find vegetable oil to appear somewhat cloudy.
This is not a spoilage alarm, but crystallization from low temperatures. Some fatty acids have started to turn into solid form, thus creating a cloudy appearance. If this happens, just place vegetable oil in a bit warmer spot.
How To Store Vegetable Oil
Vegetable oil is very sensitive to air, light, and heat. In one study, scientists exposed a bottle of sunflower oil that was exposed to light for half a day. The result is shocking – its shelf life was halved compared to bottles stored in the dark.
Clearly, it’s important to keep vegetable oil in a cool and dark place. Once opened, you can store it in the fridge to prevent it from going rancid too fast. But, that won’t actually extend its one-year shelf life.
When it comes to vegetable oil, the packaging is extremely important. Ideally, you want to buy brands that use dark or even opaque bottles. That way, you can be sure the product wasn’t exposed to light for too long.
However, if you do buy vegetable oil in a clear container, it’s important to transfer it to a different one once you come home.
But what’s the best packaging for vegetable oil?
Tinplate containers have proven to be quite practical. They offer great protection from light, air, moisture, and microorganisms. The inside of such a container is also covered with a special food-approved protection layer that prevents corrosion.
Glass bottles are one of the most common packaging for vegetable oils. But while glass does a great job at keeping the air out, it has to be dark in order to keep oil safe from light as well.
Still, there’s a handy little trick you can do in case you’ve bought a see-through bottle of vegetable oil. Just wrap the bottle in aluminum foil and it will be protected.
Metal and glass are the only packages that will keep vegetable oil safe from air and moisture. Of course, this is only true if you keep the container sealed well when not in use.
Nowadays, vegetable oil is often sold in plastic containers. There are two reasons for that – it’s cheap and lightweight. Plastic packaging can’t compare to metal and glass when it comes to extending shelf life. But if you plan on going through the bottle in a month, that doesn’t really matter.
Finally, let’s talk about freezing a bit. Vegetable oil doesn’t actually freeze. But if it gets cool enough, the molecules will stop moving around, and the oil will appear to be solid.
But here’s the thing – freezing vegetable oil won’t actually extend its shelf life. It will still last a year or two (as the packaging indicates). But freezing will definitely slow down the rancidification process.
Freezing and thawing won’t affect its structure or quality. When you’re ready to defrost vegetable oil, just leave it at room temperature until it becomes liquid.
Final Thoughts
Vegetable oil has a relatively long shelf life. Oils such as sunflower, canola, and olive can stay fresh for up to two years unopened. More delicate tyles like sesame and nut oils have a shorter shelf life of just a year.
While it doesn’t spoil, vegetable oil turns rancid. To slow down the process, it should be kept in a cool and dark place, with a properly sealed container.
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