Does Mayonnaise Go Bad? How Long Do They Last?

logo by Editorial Staff | Updated on July 3rd, 2022

Is it possible for mayonnaise to go bad? How long does mayonnaise last, and how can you tell if it’s gone bad? Here’s a quick reference guide.

Mayo! It’s one of the world’s most popular condiments. It’s a favorite with fries or a sandwich, and it’s a household staple in most households.

Natural mayonnaise ingredients and the sauce itself.

If you’re a huge fan who can’t eat anything without a dollop of mayo, you’ll probably go through it quickly before it expires.

However, if you use mayonnaise on occasion, you may keep an open jar at the back of your fridge for a few months; therefore, it’s prudent to address the question finally:

Does Mayonnaise Go Bad?

Commercially prepared mayonnaise will not expire rapidly since various components allow this food remain appetizing for weeks. However, you should be concerned about a handmade product, even if the problem is frequently caused by cross-contamination with other foods rather than the prepared mayo itself.

Mayonnaise Ready-Made

Commercial mayonnaise comprises egg yolk, oil, and vinegar. However, acid and preservatives kill microorganisms, extending the product’s life and preventing it from rotting quickly.

Mayonnaise made from scratch

Because the eggs used in the preparation are not pasteurized, the danger of food poisoning is increased. Prevent problems by producing the quantity of mayo you can consume in a single sitting and avoiding utilizing leftovers for an extended period.

How Long Will Mayonnaise last?

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

However, it will persist two to three months after that date in most situations. Nobody can tell you how long it will take because it relies on the quality of the product, as well as the components and seasonings it includes. Often, you may utilize it for at least a month or two after the expiration date.

Mayonnaise typePantryFridge
Homemade/4 to 7 days
Opened, ready-made/1 to 2 months
Unopened, ready-made3 to 4 monthsOne year

How long does mayonnaise last after it has been opened?

After you’ve opened your mayonnaise, keep it in the refrigerator, according to experts. When refrigerated, opened mayonnaise from store-bought bottles, such as Hellmann’s, will keep for 2-3 months. In addition, the chilly temperature in the refrigerator lowers the pace at which germs in mayonnaise multiply, increasing its shelf life.

How long does unrefrigerated mayonnaise last?

Because egg yolk is one of the main components of mayonnaise, it is very perishable. If a jar is opened, it has a shelf life of around 8 hours if it is not refrigerated. As a result, leaving it out overnight will be useless to you in the morning.

How long does unopened mayonnaise last?

Unopened mayonnaise jars have a shelf life of 3-4 months after the best by date. The date is inscribed on the side of the mayonnaise container. The pantry has a shelf life of three to four months when stored in the pantry. It will keep for up to a year if kept cold and unopened.

How long will homemade mayonnaise last?

Homemade mayonnaise may only be stored in the refrigerator for up to a week. When this time has passed, throw it away since there is a greater danger of salmonella germs forming in the egg yolk. To avoid this, commercial producers pasteurize eggs. However, the eggs you have at home may not have been pasteurized.

Is it safe to keep mayonnaise out overnight?

No, it is not OK to leave mayonnaise out overnight.

Mayonnaise is prepared from oil, egg yolk, vinegar, or lemon juice, as we all know. These components might spoil fast.

Homemade mayo has a higher risk of spoiling than professionally prepared mayo since the latter is filled with preservatives that can kill hazardous germs such as salmonella.

Furthermore, professionally prepared mayonnaise is created with pasteurized eggs, reducing foodborne disease risk.

If you make your mayonnaise at home, it’s best to consume it within four days; the same day is even better.

Also, ingesting mayo that has been left out overnight at room temperature is NOT SAFE since bacteria develops quite quickly in this storage environment.

The USDA recommends that food that has been left out in temperatures ranging from 40 °F to 140 °F for more than two hours be discarded immediately.

This contradicts what they say about mayo, yet we like cold meals.

Remember, you deserve delicious, fresh meals. Why take the chance?

Will Mayonnaise ruin my salad or sandwiches?

There have been reports of mayonnaise becoming rancid, causing other meals to spoil prematurely, and causing food illness. But, in a nutshell, that’s a misunderstanding.

Because mayonnaise is very acidic, germs cannot thrive in it. Guess what isn’t very acidic and doesn’t do anything to defend itself from hazardous bacteria? The remainder of the salad or sandwich components.

So, if you ever had a food illness from eating something containing mayo, the condiment is the least likely culprit. Its presence did not, in any way, accelerate bacterial growth.

And if you had a stomach ache practically every time you ate food with mayo on a picnic, keeping the meal warm was likely the problem, not the presence of mayo.

How to Determine Whether Mayonnaise Is Bad

Even though it may appear evident to some, mayonnaise can degrade without displaying visible indicators of deterioration. However, there are five distinct techniques to determine whether or not your mayonnaise is safe to eat.

Texture Modifications:

The mayonnaise should be creamy in texture. Inside the jar, it should not separate. If you observe your mayonnaise separating and liquid accumulating on top, it’s time to toss it.

This can occur as a result of bacterial overgrowth. So, avoid eating poor mayo because it might cause serious food illness.


One of the first indicators of rotten mayonnaise is discoloration. Mayonnaise is a creamy white tint. When bacterial overgrowth occurs, the hue turns yellow or brown. It may not be particularly noticeable, but it is enough to make a difference.

If this occurs, it is likely that you did not properly close the lid of the mayonnaise jar or that it was left at room temperature for an extended period.

Unusual Smell

While mayonnaise contains vinegar, it does not have an extremely sour or acidic flavor. In addition, it has very little to no scent. So, if your mayonnaise begins to smell highly acidic or nasty, you know it’s no longer safe to eat.

Sour Flavor

It might be difficult to detect if the mayonnaise is beady only by looking at it and smelling it. You have to try it in certain circumstances. Don’t eat a heaping dollop of mayonnaise!

Instead, take a small amount and taste it. If the mayonnaise tastes sour or too pungent, discard it. Unless it has gone bad, mayonnaise does not change the flavor.

Visible molds

This one is self-evident. Molds and spores should not be present in your mayo. Molds can grow if it is not properly stored because it is largely fat and liquid. Consuming moldy mayonnaise might lead to major health problems.

What Happens If You Consume Old Mayonnaise?

Assume you ate rotten mayonnaise by mistake. So, what now? What effect will it have on your health?

If you consume outdated mayonnaise, you may get stomach discomfort and diarrhea. In addition, because mayonnaise is essentially raw eggs, it has a salmonella risk, so use caution.

A Salmonellosis infection can cause typhoid fever. This is unlikely to happen with a few spoonfuls of mayo, but it is possible.

When mayonnaise expires, the acidity level skyrockets. It not only smells horrible, but it also tastes exceedingly nasty. As a result, it might induce acid reflux and heartburn.

What can I do with stale mayonnaise?

Don’t throw out that container of old mayonnaise; there are still some uses for it. Dab a little amount of it onto a dry cloth and wipe it over your stainless steel appliances and silverware to restore its luster! Put some of it between squeaky hinges in your home and enjoy noiseless door and window opening and shutting!

Making and Fermenting Homemade Mayonnaise

Let’s face it: we all prefer homemade mayonnaise over store-bought jars. But they’re a headache to manufacture and don’t last long. Did you know that you can ferment your homemade mayonnaise to keep it longer than store-bought mayonnaise?

It’s quite simple and tastes a lot better and creamier! The following is how we produce fermented homemade mayonnaise:


  • Food processor 
  • three egg yolks
  • a quarter cup of olive oil
  • 14 tsp turmeric 14 tsp dry mustard 14 tbsp lemon juice/ vinegar
  • Season with salt to taste
  • 1 teaspoon whey


  • In a blender, combine the eggs, lemon juice, and whey.
  • Blend in the spices and salt for a few seconds.
  • While the food processor is running, drizzle in the oil a few drops at a time. O it gently until the sauce thickens.
  • After adding all the oil, beat it until you’re happy with the consistency. If you overbeat the mayonnaise, it will separate.
  • Close the lid securely on the mayo in a glass jar.
  • Refrigerate the container after leaving it on the counter overnight.

How to Store Mayonnaise

To keep bacteria at bay, your mayonnaise should be completely sealed before opening. Once sealed, store it in a cool, dry place away from sunlight, moisture, and heat sources, just like any other jar. Of course, a pantry is preferable, but anywhere away from your oven or stove will do.

When it comes to storage, once the mayonnaise has been opened, there is much debate as to whether or not you should keep it refrigerated!

Keeping your unopened mayonnaise out of the fridge is considered safe, so don’t worry if you forget to stick it in the fridge after you’ve started using it.

However, it is highly recommended to keep your mayo refrigerated. It will last a lot longer and preserve the freshness and flavor for an extended period.

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

Mayonnaise: How to Freeze It?

We already established that you could freeze mayonnaise, so how do you do it? Let’s go through everything, so you know exactly how to maintain your mayonnaise in wonderful shape for a short time.

  1. Use freezer-safe glass bottles: Mayonnaise is notoriously difficult to freeze without causing the components to break down or separate, rendering the mayonnaise unattractive or even worthless. You must use a sterilized freezer-safe glass bottle to avoid these things from happening.
  2. Fill the jar with: Fill the jar halfway with the mayonnaise you wish to freeze. Make sure to allow approximately an inch of space at the top of the jar for the mayo to expand as it freezes. After that, get as much air out of the jar as possible before sealing it tightly.
  3. It should be labeled: Before placing your mayo in the freezer, write the date on the jar or anywhere else you’ll remember it. This way, when you take the mayonnaise out of the freezer in a few days, you’ll know precisely when you placed it in.

How Should Mayonnaise Be Thawed?

Now that you know how to freeze mayonnaise, it’s time to learn how to defrost it when you’re ready to eat it.

When you’re ready to use your frozen mayo, take it out of the freezer and set it on the bottom shelf of your refrigerator to thaw.

The mayo will most likely separate as a result of this. This will be less obvious if the mayo is store-bought, but it will still happen. When this happens, pour the mayo into a mixing bowl and whisk it with an electric mixer set to high speed for at least a few seconds.

So, Does Mayonnaise Go Bad?

Preservatives in shop-bought mayonnaise will keep your mayo good for years before you break the seal and open it.

However, your opened mayonnaise will eventually go bad. But when it does, it’ll be very obvious by the sour smell and green mold growing on it.

To keep it as fresh as possible, keep it refrigerated!

Following our tips, your mayonnaise will last up to 4 months!


Editorial Staff

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