Vegetable oil's shelf life depends heavily on whether it's opened and how it's stored.
Unopened Vegetable Oil
An unopened bottle of vegetable oil, stored correctly in a cool, dark place, can last for up to two years. Several sources confirm this, including The Daily Meal, which states that unopened oil can last about two years in a dry and cool area. However, StillTasty notes that an unopened bottle will generally last for a period of time, implying some variability.
Opened Vegetable Oil
Once opened, the shelf life significantly reduces. Opened vegetable oil typically lasts for six months to a year. [Many sources](https://www.foodandwine.com/how-to-store-oil-8634510, https://bioukfuels.co.uk/blog/does-vegetable-oil-go-off/) corroborate this, stating a shelf life of 12-18 months for opened oil stored properly. However, the USDA suggests a shorter shelf life of only 4 months for unopened olive or vegetable oils.
Factors Affecting Shelf Life
Several factors influence how long vegetable oil remains usable:
- Storage: Keep oil in a cool, dark, and dry place. Avoid exposure to heat and light.
- Exposure to Air: Oxygen causes rancidity. Minimize air exposure after opening.
- Contamination: Avoid contaminating the oil with water or food particles.
Signs of Rancidity
Even before the expiration date, check for these signs of rancidity:
- Off odor: A foul or unpleasant smell indicates spoilage.
- Changes in taste: Rancid oil will taste bitter or unpleasant.
- Cloudy appearance: The oil may become cloudy or discolored.
Remember to always prioritize your senses. If the oil smells or tastes off, discard it, regardless of the expiration date.
