Refrigerate or Leave Out? The Truth About Mayonnaise
Does Mayonnaise Need Refrigeration?
Mayonnaise is a kitchen staple, but confusion remains over safe storage.
The question matters because improper handling can raise
the risk of foodborne illness and shorten shelf life.
What It’s Made Of
Mayonnaise is an emulsion of oil, egg yolks, and acid.
The acid slows bacteria, but “it does not eliminate risk entirely.”
Store-bought versions use pasteurized eggs and preservatives,
making them safer than homemade mayonnaise, which is “far more vulnerable to spoilage.”
When to Refrigerate
Once opened, “store-bought mayonnaise… should always be kept refrigerated.”
Homemade mayonnaise must stay cold and is best used within “3–5 days.”
Leaving it out briefly during a meal is fine, but not for hours.
Bottom Line
“Refrigerate mayonnaise after opening,” avoid long exposure to heat, and use clean utensils.
Proper storage protects both safety and quality.
