Is mayonnaise perishable or not? What is the shelf life of mayonnaise, and how can you tell if it’s gone bad?

Mayonnaise is one of the most widely used condiments on the planet. It’s a household staple that goes great with fries or in a sandwich.

If you’re a big fan who can’t eat anything without a dollop of mayo, you’ll probably finish it before it expires. If you only use mayonnaise occasionally, you may find yourself with an open jar at the back of your fridge for a few months.

Thus, it’s a good idea to learn more about its 

What happens if mayonnaise goes bad?

Mayonnaise purchased at a store will not spoil rapidly since it contains additives that keep it delicious for weeks.

However, you should be concerned about a homemade product, even though the problem is usually caused by cross-contamination with other foods rather than the produced mayonnaise itself.

Commercial mayonnaise

Commercial mayonnaise is made up of egg yolks, oil, and vinegar. On the other hand, acid and preservatives kill bacteria, extending the product’s life and preventing it from rotting quickly.

Homemade mayonnaise

The danger of food illness is greater because the eggs used in the recipe are not pasteurized. Make only as much mayo as you can eat in a day to avoid any problems, and don’t keep leftovers for too long.

Shelf life of mayonnaise

Because it contains long-lasting chemicals and preservatives, unopened ready-made mayo has a long shelf life, frequently exceeding a year. Always verify the best-by date before purchasing this product, and use it at the time when it is at its best.

In most cases, however, it will extend two to three months beyond that date. Nobody can tell you how long it will take because it relies on the product’s quality and the components and seasoning it contains.

You can use it for at least a month or two after the expiration date.

Type of mayonnaisePantryRefrigerator
Homemade4 to 7 days
Opened and ready-made1 to 2 months
Unopened and ready-made3 to 4 months1 year
Mayonnaise in a glass jar with a spoon on white wooden boards.

Mayonnaise after opening

Once you’ve opened your mayonnaise, experts recommend storing it in the refrigerator. When refrigerating store-bought mayonnaise bottles like Hellmann’s, the opened mayonnaise will last 2-3 months.

The cold temperature in the fridge prevents the growth of bacteria in mayonnaise, allowing it to last longer.

Mayonnaise unrefrigerated

Because egg yolk is one of the main ingredients of mayonnaise, it is highly perishable. If you don’t refrigerate a jar once it’s been opened, it only lasts around 8 hours.

As a result, if you leave it out overnight, it will be useless in the morning.

Mayonnaise unopened

After its best-by date, an unopened jar of mayonnaise can be kept on the shelf for 3-4 months. On the side of the mayonnaise container, you can see the date inscribed on it.

The pantry has a shelf life of three to four months when stored in the pantry. If kept chilled and unopened, it can last up to a year.

Homemade mayonnaise

The mayonnaise you prepare at home will only keep in the refrigerator for a week. After this time, remove the egg yolk since there is a greater danger of salmonella germs forming.

To avoid this, commercial manufacturers pasteurize eggs. However, the eggs you have at home may not have been pasteurized.

Is it acceptable to leave mayonnaise out overnight?

No, it’s not a good idea to leave mayo out overnight. Mayonnaise is prepared from oil, egg yolks, vinegar, or lemon juice, as we all know.

These substances have a short shelf life. Compared to professionally prepared mayo, homemade mayo has a higher risk of deterioration because the latter is fortified with additives that can eliminate hazardous bacteria like salmonella.

Furthermore, commercially prepared mayonnaise contains pasteurized eggs, lowering the risk of foodborne illness. If you’re producing your mayonnaise at home, it’s best to consume the refrigerated food within four days, preferably the same day.

Also, keep in mind that eating mayo that has been left out at room temperature overnight is unsafe because bacteria grows quite quickly in this storage state. Food that has been left out for more than two hours at temperatures ranging from 40 to 140 degrees Fahrenheit should be thrown away immediately, according to the USDA.

This appears to contradict what they say about mayonnaise, yet we prefer to keep our dishes refrigerated.

Can mayonnaise spoil my salad or sandwiches?


Let’s start with reports of mayonnaise getting rancid, causing other meals to spoil prematurely, and causing food illness. In a nutshell, that is a misunderstanding. Bacteria cannot grow in mayo because it is highly acidic.

Guess what’s not very acidic and doesn’t do a great job protecting itself from hazardous bacteria? The rest of your salad or sandwich’s ingredients.

So, if you ever had a food illness from eating something containing mayonnaise, the condiment is the least likely cause. The fact that it was there did not affect bacterial growth.

And if you got a stomach ache practically every time you ate food with mayo on a picnic, it was probably the temperature of the food, not the presence of mayo, that was the problem.

Detecting a bad mayo

As some people believe, mayonnaise can become bad without presenting evident indications of spoiling. However, some distinct techniques determine whether or not your mayonnaise is safe to consume.


The mayonnaise should be thick and creamy. Inside the jar, it should not separate. So, if your mayonnaise separates and liquid collects on top, it’s time to toss it out.

This can happen as a result of bacterial overgrowth. So be careful not to eat poor mayo because it can cause serious food sickness.


One of the first indicators of rotten mayonnaise is discoloration. Mayonnaise is a creamy white tint. The hue shifts to yellow or brown when there is bacterial overgrowth.

It may not be a huge difference, but it is noticeable. If this happens, you likely didn’t properly close the mayo jar lid or left it at room temperature for too long.


Despite the presence of vinegar, mayonnaise does not have an extremely sour or acidic flavor. It doesn’t have much of a scent, to begin with. So if your mayonnaise begins to smell sour or rancid, you know it’s time to throw it out.


It can be difficult to know if the mayo is bead solely by looking at it or smelling it. You have to try it in certain circumstances. Do not consume a large dollop of mayonnaise, though! Instead, take a small sample and savor it.

Throw away any mayo that tastes sour or unpleasant. Unless it has gone bad, mayonnaise does not change its flavor.


This one is self-evident. Molds or spores should not be present in your mayo. Mold can grow if you don’t store it correctly because it’s largely fat and liquid. Moldy mayonnaise should not be consumed since it poses a major health risk.

What happens if you eat mayonnaise that has expired?

Assume you ate rotten mayonnaise by mistake. So, what’s next? What effect will it have on your health? It’s possible to get stomach problems and diarrhea if you eat outdated mayonnaise.

Because mayo is essentially raw eggs, it poses a danger of salmonella, so use caution.

Typhoid fever can also be caused by a Salmonellosis infection. It’s unlikely that a few spoons of mayo will cause this, but it’s possible. The acidity of mayonnaise rises dramatically as it ages.

It not only smells horrible, but it also tastes foul. As a result, it may cause acid reflux and heartburn.

What can I do with mayonnaise that has gone bad?

Don’t throw out that jar of mayonnaise that has gone bad; there are still some uses for it. Rub your stainless steel appliances and silverware with a small amount on a dry cloth until they sparkle again! Put some of it between your house’s squeaky hinges and enjoy the quiet opening and closing of your doors and windows!

Making a homemade mayo

Natural mayonnaise ingredients and the mayo sauce itself.

We all prefer homemade mayo over store-bought jars, let’s face it. However, they are time-consuming to prepare and do not last long.

Did you know that you can ferment your homemade mayonnaise to keep it longer than store-bought alternatives?

It’s very simple and tastes a lot better and creamier as a result. Here’s how we create cultured mayonnaise at home:

Things you need:

  • 3 egg yolks
  • ¼ teaspoon turmeric
  • ¼ teaspoon dry mustard
  • ¼ tablespoon lemon juice or vinegar
  • ¾ cup olive oil
  • Salt 
  • 1 tablespoon whey
  • Hand blender food processor


  1. Blend the eggs, lemon juice, and whey in a blender.
  2. Blend in the spices and salt for a few seconds.
  3. Start adding the oil a few drops while the food processor is running. Gradually increase the heat until the sauce begins to thicken.
  4. After adding all the oil, beat it until it’s the consistency you want. Overmixing may cause the mayo to separate.
  5. Fill a glass jar halfway with mayonnaise and carefully close the lid.
  6. Refrigerate the container after leaving it on the counter overnight.

How to keep mayonnaise fresh

Your mayonnaise should be completely sealed before opening to prevent bacteria, and you can store it like any other jar in a cold, dry area away from sunlight, moisture, and sources of heat while it is sealed.

A pantry is ideal, but any location away from your oven or stove would suffice.

When it comes to storing mayonnaise after it’s been opened, there’s a lot of controversy about whether it should be kept refrigerated or not! Keeping unopened mayonnaise out of the fridge is considered safe, so don’t worry if you forget to put it in the fridge after you’ve begun using it.

It is, however, strongly advised that you keep your mayonnaise refrigerated. It will stay much longer and retain its freshness and flavor for longer.

The situation is completely different for homemade mayonnaise, which is perishable and should be kept refrigerated at all times.

What is the best way to freeze mayonnaise?

We’ve established that mayonnaise can be frozen, so how do you do it? Let’s talk about it so you’ll know how to preserve your mayonnaise in tip-top shape for a short time.

  • Use glass bottles that can be frozen: Mayonnaise is difficult to freeze without the contents breaking down or separating, rendering the mayonnaise unattractive or even worthless. To avoid these problems, use a freezer-safe glass bottle that has been disinfected.
  • Fill the jar: Fill the jar halfway with the mayonnaise you wish to freeze. Make sure there’s about an inch of space at the top of the jar to allow the mayo to expand as it freezes. After that, remove as much air as possible from the jar before sealing it tightly.
  • It should be labeled: Before you put your mayo in the freezer, make a note of the date you first put it in the freezer on the jar or anywhere else you’ll remember it. You’ll know exactly when you put the mayo in when you take it out of the freezer in a few days.

How do you defrost mayonnaise?

Now that you know how to freeze mayonnaise, it’s time to figure out how to thaw it when you’re ready to eat it. Remove your frozen mayo from the freezer and thaw it on the lowest level of your fridge when you’re ready to use it.

The mayo will most likely separate if you do this. If you use store-bought mayo, this will be less obvious, but it will almost certainly happen.

When this happens, pour the mayonnaise into a mixing bowl and whisk it for at least a few seconds with an electric mixer set to high speed.

Last thoughts

The preservatives in store-bought mayonnaise will keep your mayonnaise fresh for years before you open it. Your mayonnaise, on the other hand, will go bad after a while.

When it does, though, the foul odor and green mold developing on it will be very noticeable. Keep it refrigerated to keep it as fresh as possible!