Refrigerate or Leave Out? The Truth About Mayonnaise Storage

Mayonnaise is often treated as a food that can spoil quickly, but commercial mayonnaise is made with safety in mind. Most store-bought mayonnaise uses pasteurized eggs and acidic ingredients. These features help slow the growth of harmful bacteria. Still, proper mayonnaise storage is important, especially after the jar has been opened.

The main risk often comes from how mayonnaise is handled. Using a dirty knife or spoon can introduce bacteria into the jar. Even a small amount of food residue can affect its safety. Leaving an open jar at room temperature for too long can also increase the risk of bacterial growth.

For this reason, mayonnaise should be refrigerated after opening. Keeping the jar cold helps maintain its quality and reduces the chance of spoilage. Always close the lid tightly after use. It is also best to use a clean utensil each time you take mayonnaise from the jar.

Food safety experts also recommend paying attention to storage instructions on the product label. Different mayonnaise products can have different ingredients and storage requirements. Following the manufacturer’s instructions is the safest approach.

If mayonnaise has been left out for an extended period, it is better to be cautious. The same applies if the product has an unusual smell, color, or texture. However, food can sometimes become unsafe without obvious changes in appearance. When in doubt, throwing it away is the safer choice.

So, should mayonnaise be refrigerated? Yes, especially after opening. Commercial mayonnaise is generally designed to be a safe food when stored and handled correctly. Refrigeration, clean utensils, a sealed container, and good food-handling habits can help keep mayonnaise fresh and safe to eat.

The simple rule is easy to remember: refrigerate opened mayonnaise, keep it sealed, use clean utensils, and follow the storage instructions on the label.