Refrigerate or Leave Out? The Truth About Mayonnaise Storage
Mayonnaise is one of those foods people often wonder about: Does it really need to stay in the refrigerator? The answer depends on whether the jar is unopened or has already been opened.
Unopened Mayonnaise
An unopened, commercially prepared jar of mayonnaise can generally be stored in a cool, dry pantry until its printed best-by date, as long as the package has not been damaged and the manufacturer does not specify otherwise.
Keep it away from direct sunlight and heat. A hot kitchen, garage, or area near an oven is not a good storage location.
Opened Mayonnaise
Once the jar has been opened, refrigeration is recommended. Keep it tightly covered and return it to the refrigerator after each use.
Refrigeration helps maintain the product’s quality and slows spoilage.
How Long Can Mayonnaise Sit Out?
Don’t leave opened mayonnaise sitting at room temperature for extended periods. According to food-safety guidance, perishable foods should generally not remain in the 40–140°F (4–60°C) temperature range for more than 2 hours, or more than 1 hour when the temperature is above 90°F (32°C).
This is particularly important for mayonnaise-based salads containing ingredients such as eggs, chicken, tuna, or potatoes.
What About Homemade Mayonnaise?
Homemade mayonnaise deserves extra care because it is often made with raw or lightly cooked eggs. Keep it refrigerated and use pasteurized eggs when appropriate. Follow a reliable food-safety recipe and don’t leave homemade mayonnaise at room temperature.
Signs You Should Throw It Away
Discard mayonnaise if you notice:
- An unusual or unpleasant odor
- Mold
- Significant discoloration
- An unusual texture
- A damaged, leaking, or bulging container
- Any doubt about how long it has been stored unrefrigerated
Don’t taste questionable mayonnaise to determine whether it is safe.
The Simple Rule
Unopened commercial mayonnaise: Store according to the label, usually in a cool pantry.
Opened mayonnaise: Keep refrigerated and avoid leaving it out for long periods.
Homemade mayonnaise: Refrigerate and handle carefully because of the ingredients used.
When in doubt, follow the storage instructions printed on the specific mayonnaise container.
