How Long Can Mayonnaise Be Left Out of the Fridge?

It’s been a contentious issue for a long time. The confusion seems to be present when it comes to mayonnaise. Does mayonnaise need to be refrigerated, or is it perfectly ok to store it in the kitchen cabinet with the other condiments? Does mayonnaise come under the two-hour rule from the FDA?

Did you know that mayonnaise is said to be invented by a french chef of the Duke of de Richelieu when the french were beating the British at port Mahon. It was to celebrate the victory!

In this article, we will unveil the truth about the shelf life of mayonnaise and answer frequently asked questions about this fantastic condiment sauce, despite its origins.

Let’s get into it.

Does mayonnaise need to be in the fridge?

The quick answer is yes, but there is more to this than meets the eye.

The general consensus from the USDA is that foods left on the side for more than two hours are a food poisoning risk and should be tossed in the bin due to the high bacteria load of the food.

But the official line from the FDA is that mayonnaise is good for 8 hours left out of the fridge. It is confusing, don’t you agree?

It would be natural to assume in the average household that every time you helped yourself to a spoon of mayonnaise, the spoon would be clean, with no double dipping) and that immediately after you had served yourself mayonnaise, the top would be sealed on the jar. This prevents bacteria from contaminating the mayonnaise.

It is a reasonable assumption to make, but how reliable is it?

If you look at the ingredients of mayonnaise in its purest form, it’s nothing more than egg yolks and olive oil, salt pepper, and maybe a squirt of lemon juice, but that’s it.

So, you could conclude that homemade mayonnaise should be kept in the fridge; otherwise, it will spoil quickly.

But the plot thickens as you look at commercial mayonnaise ingredients.

Here is what’s in a commonly sold mayonnaise:

• Rapeseed oil (78%)
•  free range pasteurized EGG and EGG yolk.
•  (8,9%), water.
•  Spirit vinegar.
•  Sugar.
•  Salt.
•  Lemon juice concentrate.
•  Flavoring.
•  Antioxidant (calcium disodium EDTA), paprika extract.

Calcium disodium EDTA is a strange additive. It can be found to prevent kidney disease but is also a poison of sorts if consumed sufficiently. Most of the ingredients seem to be okay.

The eggs are pasteurized to make them shelf stable, and there is no olive oil in the process, whereas rapeseed oil is chosen for its lesser taste profile.

Does mayo go bad unrefrigerated?

Mayonnaise is considered to be a perishable food, and as such, caution should be used when using mayonnaise.

Even though the egg yolks are pasteurized in mayonnaise (store-bought), the eggs are still susceptible to bacteria contamination.

Once the jar of mayo is open, it only has a shelf life of 8 hours unless it’s placed in the refrigerator.

This means if you leave a jar of mayonnaise on the side overnight, it needs to be discarded the following day.

The FDA does state that the mayo can be left open for 8 hours before it needs to be discarded. It is a long time to be left with the lid off!

Can warm mayonnaise make you sick?

If you mean warm, as in room temperature, you would have to think the mayo may have been out for a long time.

But warm mayo is fine. It may split slightly, but if you have ever visited a fast food burger chain, they place a hot burger on top of mayo all of the time, and you never get sick.

If you warm foods in the microwave and inadvertently forget the mayo, it will be fine and will not make you sick, essentially, you are heating the oil and the eggs, and you could guess that if heated enough, the mayo would become semi-solid.

Why does mayo need to be refrigerated?

Foods are refrigerated for one main reason, it prevents the food from spoiling so quickly when stored outside a fridge.

Foods stored outside the fridge are exposed to bacteria, bacteria are all around us, and once the bacteria take hold of food, food poisoning can occur if the food is eaten.

Bacteria multiply rapidly on proteins and carbs, so one food is not better than the other for being bacteria-resistant.

If you look at the essential ingredients for mayonnaise protein and oil, both are susceptible to being spoiled as bacteria proliferate.

Why do restaurants not refrigerate mayonnaise?

If a restaurant uses commercial mayonnaise, it is refrigerated, even if it doesn’t require refrigeration.

Commercial mayo has preservatives and high acidity. The acidic nature of the mayo prevents bacteria from growing in the mayonnaise.

Although you use a squirt of fresh lemon in homemade mayonnaise, it is not quite the same as the concentrated citrus lemons used commercially.

Food scientists have evidence that acidity prevents bacterial growth, so the commercial mayo is fine at room temperature.

Does Hellman’s mayo need to be refrigerated?

There is a difference between commercial establishments and residential dwellings. At a commercial establishment, a food inspector can arrive at any time and inspect the food for compliance with food safety laws, which never happens in a domestic setting.

For this reason, the USDA and FDA use a comprehensive umbrella approach to keep us all safe from food poisoning.

Your mayo may not have any instructions for refrigeration and storage, but it is still required to be refrigerated within 8 hours of being out of the fridge.

The U.S. Food & Drug Administration recommends that perishable foods such as mayonnaise be placed in the fridge after opening and have a shelf life of 8 weeks.

Does mayonnaise spoil easily?

No. It has a finite life, but in general terms, it does not spoil easily. ( homemade spoils quickly if not refrigerated).

According to the USDA, these acids prevent bacteria from taking hold in the mayo, which is why you can keep mayo out of the fridge for 8 hours.

However, it is considered a perishable food, meaning it should be handled with care and refrigerated after use.

What happens if you eat spoiled mayonnaise?

Cross your fingers that you don’t get food poisoning and keep well hydrated. Many bacterial infections take hold days after consuming expired food, and being hydrated can make the symptoms less severe.

It really depends on how long past the expiry date you have eaten the mayonnaise. The good thing about mayo is that it is light, creamy, and smells lovely. If the color changes, it’s easy to notice it will become light brown. If this is your mayo, toss it in the garbage.

Can you get food poisoning from mayonnaise?

Yes, but you will be unlucky if it happens. A fair amount of vinegar and other acids in mayo tend to prevent bacteria from growing, so unless the mayo is evidently rancid or has mold flecks, you are likely to be okay.

If you do get food poisoning, these are some of the symptoms you could get and in no particular order:

• Upset stomach.
• Stomach cramps.
• Nausea.
• Vomiting.
• Diarrhea.
• Fever.

The sickness should subside after two days, but if it persists, you may need to visit the ER for medical attention.

How can you tell if mayonnaise is bad?

Mayonnaise is one of the easier foods to see if it has gone bad, its normal state is creamy with a delightful aroma, but if changes occur, you can assume the mayo is bad.

Here are a few signs that all is not well with your mayo:

• Mold, mold will settle in the jar of mayo, and it will be easy to see. It may be the typical green mold or be black or brown.
• The oil will go rancid, split, and separate from the mayo, and there will be a rancid smell that is easily definable that the mayo is bad.
• Bad mayo invariably changes color from creamy to brown and yellowish, and the mayo may lose its consistency as the bacteria break down the components of the mayo. 

If this is your mayo, toss it in the garbage immediately.

What is the healthiest mayonnaise to eat?

As “healthier” alternatives, canola oil, avocado oil, and olive oil mayonnaise are readily available. The calories are the same, but both are higher in monounsaturated fats, which are good for the heart. Additionally, versions of olive oil blend with other vegetable oils to balance the flavor.

Is olive oil healthier than mayonnaise?

The benefits of olive oil mayonnaise over conventional mayonnaise Olive oil mayonnaise is preferred to ordinary mayonnaise because it is additive- and seed oil-free, gluten-free, and low in carbs.

Final thoughts

Mayonnaise is a perishable food so treat it with some caution. It is recommended to refrigerate mayonnaise and not leave it exposed to bacteria contamination. Unlike other foods that have only two hours at room temperature before they become spoiled by bacteria, mayonnaise can stay out for up to 8 hours with the lid off.

Stored correctly in the fridge, mayonnaise has a shelf life of approximately three months. However, leaving it out will shorten the shelf life.