How Long Can Mayonnaise Be Left Out of the Fridge?

How long can mayonnaise be left out of the fridge

Mayonnaise is a potentially dangerous condiment. Every summer, there are health warnings about consuming potato salad on a camping trip or a lobster roll at the ocean that has been sitting in the hot sun for hours. You could be brave and eat something anyway, which begs the issue. So how long can mayonnaise be left out of the fridge? And what, after all, is the expiration life of mayonnaise? Let’s explore!

Mayonnaise: Homemade vs. Commercial

Homemade mayonnaise also has a much shorter shelf life than commercial mayo.

Mayonnaise is usually made with raw egg yolks, which poses a small risk of salmonella infection. Pasteurized yolks are used by manufacturers, and cooks worried about salmonella could now find pasteurized eggs in stores. This raw egg is one of the reasons why mayo should be treated as a perishable item that should be served promptly or refrigerated.

Before unwrapping, most commercial mayonnaises, such as Hellman’s Genuine Mayonnaise or Sir Kensington’s Mayonnaise, are shelf-stable. That is why the bottle or jar can remain in the supermarket unrefrigerated. However, once opened, mayonnaise must be kept in the fridge, and Sir Kensington states that cooled mayonnaise will just be safe to savor for roughly 2 months from the moment you open your jar or bottle. So, if you’ve held an open jar of mayonnaise in your refrigerator for the better part of a year, it’s time to toss it.

How long can mayonnaise be left out of the fridge?

The answer is that it depends on the mayonnaise you have on hand, but chances are it’s far shorter than you imagine.

To be explicit, we’re not discussing imitation or vegan mayo. We’re discussing the shelf life of actual mayonnaise, as specified by the US government (since, of course, there’s a rule in the US about what’s deemed mayonnaise and what isn’t). In accordance with the US Food and Drug Administration, real mayonnaise in the United States must contain at least 65% vegetable oil, vinegar, lemon juice, and some form of egg yolk. The presence of egg yolk makes mayonnaise perishable and notoriously difficult to manage.

Because mayonnaise is fragile, it should be discarded if it has been left out unrefrigerated overnight. It might be perfectly fine—until you get food illness. In general, the FDA recommends discarding perishable products, including mayonnaise, after 2 hours at room temperature.

So keep that mayo in the refrigerator and replace it every 2 months, or prepare your own and utilize it right away. Just be cautious, and avoid getting salmonella from your mashed potatoes.

Further reading: How Long Can You Keep Dressing or Stuffing in the Freezer?

How can you know if mayonnaise is bad?

If you’re going to eat mayonnaise that you’re not sure about, inspect it first.

Check with your eyes for:

  • Surface growth with blue or white flecks
  • A foul or putrid odor
  • Discoloration (e.g. brown or very dark areas of mayonnaise)
  • A peculiar flavor, particularly if sour

You should only use the taste test when the additional factors are inconclusive, but mayonnaise will typically show visible signs of spoilage. If you must taste it, only place a tiny amount in your mouth and spit it out if you think it tastes awful.

Although a tiny amount of moldy mayonnaise is not likely to harm you, it is still best not to eat it.

What does expired mayo taste like?

Here’s a fun fact, an unopened can of mayonnaise can last up to several years. That means well-preserved mayo will taste exactly the same even after its expiration date.

If left for more than a year, the flavor may oxidize a bit. If your expired mayo tastes weird, it’s spoiled.

Further reading:  Can You Freeze Soy Milk?

A sour taste with a vinegar smell is a sign of spoilage. At this point, throw the mayo out immediately.

What are the risks of eating mayonnaise that has gone bad?

Eating bad mayonnaise may cause food illness because any of its components could spoil and some people are especially concerned about egg yolks. If your mayonnaise has gone bad, you could get very sick.

Food poisoning can cause everything from stomach aches to diarrhea and even hospitalization. Even though most consumers will not wind up in the hospital as a result of consuming contaminated mayonnaise, it is essential to take care of tainted foods and avoid taking unnecessary risks.

If you suspect that mayonnaise has been improperly kept or has expired, discard it.

How to preserve mayonnaise without refrigeration

There are two tried-and-true methods for storing purchased mayonnaise without a refrigerator. To prevent cross-contamination, store it in a squeeze bottle for continuous use. If you’re keeping the mayo for later, keep it in your pantry unopened. It will keep for a maximum of three months or until the stated expiry date.

Furthermore, it has been demonstrated that refrigerating mayonnaise has less to do with spoilage and more to do with flavor. It is a choice that is entirely up to you, so try both methods and see which works best for you.

How long can homemade mayonnaise be left out of the fridge?

Store-bought mayonnaise contains a lot of preservatives that help keep foods fresh and prevent the spread of bacteria while homemade mayonnaise does not contain these substances.

Also, the biggest difference is that commercial mayonnaise is made with pasteurized eggs. The pasteurization process kills any salmonella bacteria in the eggs, making them safer to consume and increasing the shelf life of the mayonnaise.

In short, homemade mayo has a much faster expiration date than store-bought mayonnaise. It’s best to be used within a week or less of being made. You should always put it back in the refrigerator after you’re done using it and don’t leave it on the counter.

Further reading: 10 Best Mini Fridges with Freezer


So, how long can mayonnaise be left out of the fridge? Mayonnaise could be left out of the refrigerator for a maximum of eight hours, which is unusually long. It is best to be refrigerated within 2 hours.


How long is mayo OK in fridge?

A jar of mayo will be safely kept in the refrigerator for about 3 months before being opened. If you’ve just opened a container, keep it in the fridge and utilize it within 2 months. However, homemade mayonnaise will only keep in the freezer for a week, so plan to use everything up before then.

Is there any mayonnaise that doesn’t need refrigeration?

Store-bought mayonnaise does not require refrigeration. As long as it hasn’t been opened, the mayo’s ingredients will keep the contents perfectly preserved. Additionally, according to a report by the NPD Group, the acidic nature of mass-produced mayonnaise inhibits the growth of food-borne illness-causing bacteria. An opened jar of mayo will also keep without refrigeration if transferred to a squeeze bottle.

Can spoiled mayonnaise make you sick?

Mayonnaise that has passed its “best by” date or has been kept in a hot environment may serve as a breeding ground for dangerous bacteria like Salmonella and Listeria. Consuming spoiled mayonnaise can cause vomiting, nausea, abdominal pains, diarrhea, and fever.

Is it okay to consume mayonnaise that has been left out overnight?

No, eating a sandwich containing mayo left out overnight is not healthy. Although mayonnaise is made with ingredients that are generally considered safe, it is very easy to spoil when left out.

When mayo is exposed to hot temperatures, it rapidly becomes a breeding ground for bacteria to spoil your food. If left unrefrigerated, these microbes can grow to dangerous amounts in a brief time and might not be eliminated even when heated. As a result, it is best to use food with mayonnaise that was prepared and refrigerated on the same day.


Here is How You Store Mayonnaise Without a Fridge,, Retrieved on May 4, 2023

How Long Can Mayonnaise Be Left Out of the Fridge – Guide,,  Retrieved on May 3, 2023


Jenny Brown
Hi, I’m Jenny. On my blog, you will find helpful advice about using and organizing the kitchen appliances. You will also receive the recommendations on choosing a compact refrigerator or freezer that best fits your demands. Besides, frozen meals from the freezer bring many incredible benefits because they ensure freshness, deliciousness, and full nutrients. Many helpful tips from experts on frozen meals will also be found.