Sealed cooking oil's shelf life varies significantly depending on the type of oil and storage conditions. Generally, unopened bottles can last for a considerable time, but opened bottles degrade much faster.
Shelf Life of Unopened Cooking Oils:
- Vegetable Oil: Unopened vegetable oil, stored in a cool, dark place, remains safe for up to two years [Source: https://www.rti-inc.com/blog/does-cooking-oil-go-bad/, https://www.thedailymeal.com/1139394/does-vegetable-oil-expire/ ]. Some sources suggest a shorter shelf life of around 4 months [Source: https://ask.usda.gov/s/article/What-is-the-expiration-date-for-cooking-oil].
- Olive Oil (Extra Virgin): Extra virgin olive oil, when properly stored, can last up to 18 months [Source: https://www.rti-inc.com/blog/does-cooking-oil-go-bad/ ].
- Crisco Shortening: Unopened Crisco shortening in a can lasts approximately two years; opened, it lasts about one year [Source: https://www.foodprepper.com/which-cooking-oil-lasts-the-longest.php].
Factors Affecting Shelf Life:
- Storage: Keep oil in a cool, dark, and dry place. Light, heat, and air accelerate rancidity.
- Type of Oil: Different oils have varying levels of susceptibility to oxidation and rancidity.
- Packaging: The type of container (glass, plastic, metal) also influences the oil's longevity.
Determining If Oil Has Gone Rancid:
Regardless of the expiration date, always check for signs of rancidity before using the oil. Discard oil if it:
- Is cloudy.
- Foams excessively.
- Has an unpleasant odor or taste.
Note on Used Cooking Oil:
Used frying oil should be stored in a sealed, light-proof container for up to three months in the refrigerator for best quality; otherwise, discard it [Source: Provided text].
