Can you leave mayonnaise out of the fridge?

In this brief guide, we will answer the query, “Can you leave mayonnaise out of the fridge?” and will discuss how long does mayo lasts?.

Can you leave mayonnaise out of the fridge?

No, you cannot leave mayonnaise out of the fridge. According to the United States Department of Agriculture, you may leave an opened jar of mayonnaise out at room temperature for up to 8 hours before using it. Mayonnaise that has been open for more than eight hours and has been kept at a temperature more than 50 degrees Fahrenheit should be thrown away.

Whereas, after the “best by” date on the box, an opened jar of mayonnaise that has been kept cold will usually keep its optimum quality for 2 to 3 months.

Commercially, all egg products used in mayo have been pasteurized, which is why it has such a long shelf life when not refrigerated. You don’t have to refrigerate the mayo for weeks if you store the main jar in a cold, dark location and avoid cross-contamination.

People have no problem spreading mayo on their sandwich and then dipping the knife back into the container with bits of crumbs, tomato seed, or avocado spread on it and scooping up more mayo for the next slice without worrying about any airborne microorganisms that may have settled on it during this time. Most people have no problem doing this.

The first thing to deteriorate and make mayo “go bad” is the “non-mayo” stuff. All of the additional ingredients besides mayo are what cause potato salads and other similar dishes to deteriorate in hot temperatures throughout the summer, as well as giving mayo a poor reputation.

This is why the “refrigerate after opening” recommendation is on all mayo labels: it’s there to help prevent people from accidentally becoming infected and dying as a result.

Unrefrigerated, how long does Mayo last?

Each of us is well aware of the telltale indications that summer is on its way. Between the barbecues, picnics, beach trips, and camping plans, each year the warmer weather brings fun outdoor activities filled with great food.

Great cuisine is seldom without caution, however: drink lots of water, keep your ice in a high-quality cooler, and don’t expose your mayonnaise to the sun. That last piece of advice (usually given by a paranoid mother) always seems to stir up some debate.

Unrefrigerated, how long does Mayo last?

Mayonnaise isn’t kept in the refrigerator section of the grocery store, as you’ve probably noticed. Because it has been pasteurized, it has a decently long shelf life while the container is still sealed. You’re safe to keep it unopened and sealed in your pantry for about three or four months after its “best used by” date.

If for some reason you’re looking to store mayo for longer, you can refrigerate it unopened and sealed for up to a year. Even though acids in mayonnaise help kill bacteria, it still needs to be stored in the refrigerator once opened.

It will keep for two to three months if you follow these instructions. Open jars of mayonnaise, on the other hand, go bad in about eight hours if not refrigerated. Putting it in the garbage is the best course of action if you’ve accidentally left it out on the counter overnight.

Mold or spore development, as well as a foul odour, are sure indications that your mayo is rancid. It’s possible that your mayonnaise is a shade darker than usual as a result of this.

The Reality

Potato salad with mayonnaise is perfectly safe to serve at your next family picnic and there is very little risk of anybody getting sick from it. Despite the fact that the product contains eggs, it does not adhere to the same set of standards as eggs consumed on their own.

Store-bought mayo is often prepared using vinegar or lemon juice, although other acids may also be used. Foodborne infections cannot survive in the acidified environment, therefore the product destroys them. As a result, your mayo will be free of Salmonella and prevent the growth of any other germs.

Make Your Own Mayonnaise at Home

You must keep homemade mayonnaise in the refrigerator. Homemade mayonnaise, as opposed to store-bought, often lacks the acid and salt concentrations required for preservation. Preventing bacterial development and preserving quality go hand in hand with refrigeration when making homemade mayonnaise. 

In the refrigerator, a new batch of homemade mayonnaise lasts for about five days. Throw away the mayonnaise after five days if you haven’t used it.


Freezing temperatures have an impact on mayonnaise in the same way as temperatures over 40 F have an impact on the flavour and sometimes cause the mayonnaise to become brown once the jar is opened. Mayonnaise changes texture, thickness, and consistency when chilled to 0 degrees Fahrenheit or below. Even for a short period of time, freezing mayonnaise reduces its quality.

To read more about leaving hard-boiled eggs out click here

Other FAQs about Mayonnaise that you may be interested in.

Can you heat mayonnaise?

Can you cook with mayonnaise?

How do you know if mayonnaise is bad?


In this brief guide, we answered the query, “Can you leave mayonnaise out of the fridge” and discussed how long does mayo last?