How long does vegetable oil last after use?

Vegetable oil is a staple in most kitchens and used for various cooking applications like frying, baking, sautéing, etc. But like most cooking oils, vegetable oil can go bad after opening and using it. The shelf life of vegetable oil depends on several factors like the type of oil, storage method, and how it was used. Here’s a quick look at how long different types of vegetable oils last after opening.

Quick Summary

  • Unopened vegetable oil lasts 1-2 years past the printed date.
  • Opened vegetable oil lasts 3-6 months if stored properly.
  • Frying oils last 1-3 months after opening.
  • Proper storage extends shelf life – keep oil in cool, dark place.
  • Look for changes in smell, taste, and texture to indicate spoiled oil.
  • Rancid oil has strong, unpleasant smell and bitter taste.

How to Tell if Vegetable Oil Has Gone Bad

Because vegetable oils have a relatively long shelf life compared to other cooking oils, it can be tricky to tell if your oil has expired or gone rancid. Here are some signs that your vegetable oil has spoiled and needs to be discarded:

  • Smell – Fresh vegetable oil has a mild, neutral smell. Rancid oil will have a strong, unpleasant odor.
  • Taste – Oil that tastes bitter, acidic, or unpleasant is rancid.
  • Color – The color may change to a darker yellow/orange shade.
  • Texture – Bad oil may become thicker in consistency or appear gloopy.
  • Smoke point – Oil that smokes or burns at a lower temperature is likely spoiled.
  • Foaming – Excess foaming when heating oil can indicate it’s gone bad.

Shelf Life of Unopened Vegetable Oils

Unopened, factory-sealed vegetable oils are extremely shelf stable and will stay fresh for a very long time. Here are the approximate shelf lives of common vegetable oils before opening:

Vegetable Oil Unopened Shelf Life
Canola 2 years
Corn 1-2 years
Cottonseed 2 years
Grapeseed 1-2 years
Olive 2 years
Peanut 1-2 years
Safflower 2 years
Sesame 2 years
Soybean 1-2 years
Sunflower 2 years
Vegetable (blend) 1-2 years
Walnut 6-12 months

The printed “best by” or “expiry” date on the bottle is usually 1-2 years from the packaging date, which provides a good timeline for maximum freshness of unopened oils.

How Long Does Opened Vegetable Oil Last?

Once opened, vegetable oils have a shorter shelf life and their quality begins to degrade over time. The timeframe depends on storage conditions and how the oil was used. Here are some general guidelines for how long vegetable oils last after opening:

  • In pantry or cupboard – 3-6 months
  • Refrigerated – 6-12 months
  • Frying oils – 1-3 months
  • Infused oils – 1-2 months
  • Expeller/cold-pressed oils – 3-6 months (refrigerate)

Oils that have been heated to high temperatures during frying will degrade much faster. Their antioxidant compounds break down and harmful free radicals accumulate over repeated frying sessions. For best quality, frying oil should be discarded after 1-3 months.

How to Extend Vegetable Oil Shelf Life

Proper storage is key for maximizing the shelf life of vegetable oils after opening. Here are some tips for keeping your oils fresh longer:

  • Purchase oils in smaller containers if possible, to limit air exposure after opening.
  • Store oil in a cool, dark place like a pantry or cupboard.
  • Keep oil away from heat, light, and humidity.
  • Transfer oil to an airtight container like a mason jar if not using the original bottle.
  • Refrigeration can prolong shelf life of delicate oils like walnut or flaxseed.
  • Make sure bottle is tightly sealed between uses.
  • Use clean utensils when dispensing oil to prevent contamination.
  • Don’t store oil above the stove or near a hot oven.

Oils stored properly in a pantry will keep for 3-6 months. Refrigerating oils extends shelf life for an additional 3-6 months. Consider freezing oil for long term storage past 1 year.

Specific Vegetable Oils and Their Shelf Lives

Shelf life can vary among different types of vegetable oils. Here is an overview of popular options and how long they last:

Canola Oil

  • Unopened: Up to 2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Corn Oil

  • Unopened: 1-2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Cottonseed Oil

  • Unopened: 2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Grapeseed Oil

  • Unopened: 1-2 years
  • Opened, pantry: 3-4 months
  • Opened, refrigerator: 6-8 months

Olive Oil

  • Unopened: 2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Peanut Oil

  • Unopened: 1 year
  • Opened, pantry: 4-6 months
  • Opened, refrigerator: 6-12 months

Safflower Oil

  • Unopened: 2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Sesame Oil

  • Unopened: 2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 9-12 months

Soybean Oil

  • Unopened: 1-2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Sunflower Oil

  • Unopened: 2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Vegetable Oil (blend)

  • Unopened: 1-2 years
  • Opened, pantry: 6 months
  • Opened, refrigerator: 1 year

Walnut Oil

  • Unopened: 6-12 months
  • Opened, refrigerator: 3-6 months

Walnut oil has a shorter shelf life than most due to its delicate flavor. Always refrigerate after opening.

Can Spoiled Vegetable Oil Make You Sick?

Consuming rancid vegetable oil likely won’t make you sick or seriously endanger your health. However, spoiled oil should still always be discarded as it creates an unpleasant flavor and loses nutritional value over time.

Oils turn rancid due to oxidation, which degrades the structure of the fat molecules. This produces free radicals and chemical compounds that give old oil its unappealing taste and smell.

The biggest risk with rancid oil is that these free radicals and toxic breakdown products act as irritants once consumed. In large enough amounts, this can potentially cause mild digestive upset like nausea, diarrhea, or vomiting in some individuals.

In addition, as vegetable oils degrade they lose their healthy polyunsaturated fats like omega-3 and omega-6 over time. So rancid oil doesn’t provide the same nutritional benefits.

While you likely won’t get violently ill from spoiled vegetable oil, you’ll be ruining the flavor of your dishes. Stick to fresh, non-rancid oils for the best quality, safety, and nutrition.

How to Dispose of Bad Vegetable Oil

Once you’ve determined your vegetable oil has gone rancid, it should be disposed of properly. Here are some safe methods for discarding spoiled oil:

  • Pour the oil into a sealable container and dispose with your household trash.
  • Mix the oil with an absorbent material like cat litter or coffee grounds before throwing away.
  • Contact your local government about oil disposal recommendations and options in your area.
  • Do not pour rancid oil down the drain, as this can clog pipes.

If you have a large amount of used cooking oil to dispose of (1 cup or more) consider setting it aside and calling a waste management company in your area to arrange pickup. Some companies recycle and repurpose used cooking oils.

Tips for Cooking with Vegetable Oil

To get the most shelf life out of your vegetable oils, follow these best practices when cooking:

  • Limit frying temperatures to 350-375°F to avoid oxidation and damage.
  • Strain your frying oil through a fine mesh sieve after each use to remove food particles.
  • Let oil cool completely before storing it after cooking.
  • Designate one oil for frying only to extend its useful lifespan.
  • Never mix fresh oil with old oil – always discard old oil fully.
  • Avoid reheating oil more than 2-3 times as it quickly deteriorates.
  • Store oils away from heat and sunlight right after opening.

With the proper use and storage methods, your vegetable oils can maintain quality and freshness for many months past the opening date. But once those telltale signs of spoilage appear, it’s time to say goodbye and replace with a fresh bottle.


Vegetable oil can remain safe and usable for 1-2 years unopened, and around 6 months once opened if stored correctly. Frying life is shorter at just 1-3 months max. Look for changes in smell, taste, color, and texture to determine if your oil is expired. With proper storage methods, keeping vegetable oils fresh for everyday use is simple. Just keep oils sealed, in cool dark places, pour carefully, and limit frying time for best longevity.

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