Yes, cooking oil does eventually expire or "go bad." The expiration date printed on the label should be considered a guideline, but it's not always accurate. Factors like exposure to air, light, and heat can cause oxidation, making the oil rancid. This process leads to a sharp smell, bitter taste, and discoloration.
Signs of Spoiled Oil:
- Rancid Odor: A strong, unpleasant smell indicates that the oil has gone bad.
- Bitter Taste: Rancid oil will have a bitter or unpleasant taste.
- Discoloration: The oil may become cloudy, darker, or have sediment at the bottom.
Storing Oil Properly:
- Cool, Dark Place: Store unopened oil in a cool, dark place, like a pantry, to extend its shelf life.
- Tightly Sealed Container: Keep the container tightly sealed to prevent air and moisture from entering.
- Avoid Direct Sunlight: Protect oil from direct sunlight, which can accelerate oxidation.
While most unopened oils can last for several months to a year, opened oils generally have a shorter shelf life. If you're unsure about the quality of oil, it's best to err on the side of caution and discard it.
