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Mayonnaise is made using raw egg yolks and oil. Of course, it can go bad! But the thing that we should be worried about is, how fast it happens and what we can do about it. Food condiments like mayonnaise are already quite unhealthy. So if we accidentally consume spoiled mayonnaise, we might end up having serious stomach issues. Whether you’re wondering how to store mayonnaise or you’d like to learn a bit more about mayonnaise, this article is for you. Today we will talk about how to tell if mayo is bad, the easy way to make and ferment your homemade mayo, and much more! If any of these topics sound interesting, keep reading!

How Long Does Mayonnaise Last?

Even though it might seem pretty obvious to some, mayonnaise can go bad without showing obvious signs of spoilage. But we have five different ways to know if your mayo is safe to eat or not.

01. Texture Changes:

The mayo should have a creamy consistency. It should not separate inside the jar. So if you notice your mayonnaise separating and liquid gathering on top, it’s time to throw it away. This can happen due to an overgrowth of bacteria. So make sure to avoid eating bad mayo as it can cause severe food poisoning. 

02. Discoloration:

Discoloration is one of the first signs of spoiled mayonnaise. Mayo is quite creamy white in color. When it gets bacterial overgrowth, the color changes and it looks yellow or brown. It might not be very drastic but enough to notice a difference. If this happens, chances are you did not close the lid of the mayo jar properly or it was at room temperature for too long.

03. Strange Smell:

Even though mayonnaise has vinegar, it does not smell overly sour or acidic. It has little to no fragrance whatsoever. So when your mayonnaise starts to smell very acidic or putrid, you know it’s no longer safe to consume. 

04. Sour Taste:

Sometimes, it’s hard to tell if the mayo is bead just from the look and smell. In those cases, you have to taste it. Don’t eat a massive spoonful of mayonnaise!Instead, take a little bit and taste it. If the mayo tastes sour or very pungent, throw it away. Mayonnaise does not change its taste unless it has gone bad. 

05. Visible Molds:

This one is pretty obvious. Hou mayo should not have any molds or spores. If you don’t store it properly, molds can develop as it is mostly fat and liquid. Do not consume moldy mayonnaise as it can cause serious health concerns. 

What Happens If You Eat Expired Mayonnaise

Let’s assume you accidentally ate spoiled mayonnaise. Now what? How is it going to affect your health? If you accidentally eat expired mayonnaise, it can cause stomach aches and diarrhea. As mayo is basically raw eggs, it has a risk of salmonella so you need to be very careful If you get a Salmonellosis infection, it can cause Typhoid fever too. This is not very likely to happen from a few spoons of mayo, but it’s a possibility. When mayonnaise expires, the acidity level increases drastically. It not only smells bad but tastes very sour too. So it can cause acidity and heartburn. 

How to Store Mayonnaise the Right Way: The Dos & Don’ts!

Mayonnaise is made using raw chicken eggs. Due to this, proper storage is necessary to keep it safe to eat. Mayo can get spoiled or contaminated very easily.We have some do’s and don’t to keep your mayonnaise fresh for longer:Never keep your mayonnaise at room temperature for more than 2 hours. According to USDA, you can keep your mayo at room temp for almost 8 hours.But we think this is not safe as we all live in different climates. If you live in a humid environment, your mayo will not last 8 hours.Keep your mayo always in the refrigerator. Don’t freeze your mayonnaise.It’s better to buy those squeeze mayo bottles instead of jars s bottles that have less contamination. Each time you use a spoon to grab some mayo, the whole jar gets contaminated and it reduces the shelf life.Don’t microwave your mayo to bring it to room temperature. 

How to Make and Ferment Homemade Mayo

Let’s be honest, we all prefer homemade mayo over store-bought jars. But they are a pain to make and don’t even last very long. Did you know you can ferment your homemade mayo to make it last longer than the store-bought options? It’s actually super easy and tastes so much better and creamier! Here’s how we make fermented homemade mayonnaise:


Hand blender food processor3 egg yolks¾ cup olive oil¼ teaspoon turmeric¼ teaspoon dry mustard¼ tablespoon lemon juice/ vinegarSalt to taste1 tablespoon whey


Put your eggs, lemon juice, and whey into a blender and mix them. Add the spices and salt and blend for a few seconds.While the food processor is on, start adding the oil a few drops at a time. O it gradually until the sauce starts to thicken. After you have added the whole oil, beat it until you are satisfied with the consistency. Do not overbeat as the mayo can separate. Place the mayo in a glass jar and close the lid tightly. Leave the jar on the countertop overnight and then refrigerate. 

Frequently Asked Questions 

01. How Long Does Homemade Mayo Last?

Homemade mayo contains no preservatives so it does not last as long as store-bought mayonnaise. If you keep your homemade mayo in the refrigerator, it will last 3-4 days. You can extend the shelf life of your homemade mayo by fermenting it. After fermenting your mayo for 5-6 hours, it can last up to 2 months in the fridge. 

02. Does Mayonnaise Need to Be Refrigerated?

Mayonnaise contains egg yolks and oil. Egg yolks do not survive well at room temperature. You need to keep your mayo in a cold environment to prevent molds from growing inside. According to the USDA, mayonnaise can not reach above 50° Fahrenheit. Anything above that spoils the mayo and causes it to separate. 

03. How Long Does Mayonnaise Last after Opening?

Once you open a jar of mayo, it will last you up to 2 months. Before it’s opened, a jar of mayo can last in the refrigerator for about three months or until it expires. 

04. How Long Can Mayo Stay Out?

Mayonnaise can sit at room temperature for up to 8 hours according to the USDA. any open mayonnaise jar that sits above 50° Fahrenheit for more than 8 hours needs to be tossed out. So if you accidentally leave your mayonnaise on the countertop overnight, it is still safe to eat. Just quickly put it back in the refrigerator. 

05. Is Hellmans Mayo Pasteurized?

Hellmann’s mayonnaise is known for its 100%free range of chicken eggs. So their mayonnaise is pasteurized and safe to eat. If you’re pregnant or have some health limitations, using Hellmann’s mayo instead of a generic one is safer and arguably better for you. 

06. Where Does Mayonnaise Come from?

Some people say mayonnaise comes from Spain, specifically Mahón. There are Spanish recipe books dated as far back as the 14th century that mentions a sauce using egg, oil, and garlic. It was called all-i-oli. The first time we saw mayonnaise in European cuisine was in the 1750s, where it was published in a cooking book and was called aioli bo. Aioli literally translates to garlic and oil. So we can say mayonnaise has been around for centuries. 

07. How Long is Mayonnaise Good for after the Expiration Date?

If you store your mayonnaise according to the USDA guidelines, it will stay fresh and edible for 3-4 months past the expiration date. The expiration date is a mere suggestion for the consumer.It’s not definite. Food can go bad before the expiration date and also can stay safe months after it. 


In this article we tried to answer how you can tell the mayo is bad and how to keep your may fresh for longer. We discussed the shelf life of both homemade and store-bought mayo so you know exactly how to preserve them. Mayonnaise is a staple for us. No good sandwich is made without a dollop of mayo.

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It’s one of those products we grab without even thinking about in the store.So make sure to keep it in the refrigerator as kids love it. we don’t want any contamination happenings as it has serious health risks! Happy eating!