mayo go bad

Does Mayonnaise Go Bad?

You throw the mayonnaise out of habit if it stays open for a few months in the fridge. But do you really have to do that? Does mayo go bad?

Mayonnaise is an indispensable addition to any good sandwich, many salads, and various dishes. Somehow we’re already used to mayo being a must-have sauce. But, unlike its sandwich siblings, ketchup and mustard, mayonnaise contains eggs and some other ingredients that are not prone to excessive duration.

Consuming spoiled mayonnaise can cause severe indigestion and food poisoning, not to mention some much more serious consequences like salmonella poisoning. Caution is always welcome. If you notice that open mayonnaise has been standing in the fridge for too long, you really need to throw it away as a precaution. How long you can count on open packaging and many other tips we bring below.

How Long Does Mayonnaise Last?

How long mayonnaise can last is impossible to say with certainty. There are a lot of manufacturers on the market, and they all put different proportions and ingredients in their products. Some add more preservatives, some less or not at all. Even in shops, you will find some mayonnaise placed in the fridge and some on the regular shelves. Here are some general guidelines to help you.

Unopened mayo

Some general rule says that mayonnaise should be good for another two to three months after the expiration date written on the package. This is true if it is unopened, whether in the refrigerator or the pantry. Yet a cooler temperature and distance from any heat sources are necessary. If you have a recently expired mayo jar, you don’t have to throw it away. However, for your safety, check for signs of spoilage.

Opened mayo

For open mayonnaise, the rule that it will last longer than shelf life does not apply. In fact, once you open the jar, the risks of spoilage begin. In the best conditions, the mayonnaise should be consumed within two months, and be sure to keep it in the refrigerator all the time. Don’t risk too much with more extended storage than that. Risk outweighs pleasure.

Homemade mayo  

If you are a fan of making homemade mayonnaise, you surely use fresh eggs in preparation, which is why your culinary craft won’t survive a long time. It would be ideal to consume homemade mayo within five days, a maximum of one week.

Can Mayo Go Bad?

Mayonnaise can and will spoil over time, without any doubt. If eggs are present in any product, you know that there is at least a small risk of food poisoning if you overlook the signs of spoilage. Here’s how you’ll most easily recognize that something is wrong with the dressing.  

Sign 1: Organic formations 

Mayonnaise can develop mold, especially if you have not used a clean spoon and other foods have contaminated it. Any suspicion of mold is an alarm to throw everything in the trash. Mold can look like white, yellowish, or brownish clumps.

Sign 2: Off smell

The odor may be sour and acidic if spoilage has occurred. When you open the jar, give it a good sniff and evaluate whether there is a change compared to the usual smell. Any deviations are a sign you should throw away the product.

Sign 3: Discoloration 

Decay can also be seen through discoloration. Again, any deviation is a warning to you to throw everything away. Usually, mayonnaise is white or slightly yellow. If you notice a different color in certain places, brownish or yellowish circles, throw everything away immediately.

What Is The Best Way To Store Mayo? 

Proper storage of mayonnaise is extremely important for its quality. Basically, if the mayonnaise in the store was in the fridge, put it in the refrigerator at home as soon as you arrive. If it was standing on a shelf, you could store it in the pantry, but it goes in the fridge as soon as you open it. Homemade mayonnaise must be refrigerated at all times. Here are some more valuable tips.

Tip 1: Adequate hygiene

It would be best always to use a clean spoon when scooping mayo from a jar. Any contamination with other foods will spoil the product in record time.

Tip 2: Don’t leave out for too long  

You should take the mayonnaise out of the fridge, take the desired amount and return it to the refrigerator immediately. Spoilage is quite possible if it stays on the kitchen counter long, especially if the temperature outside is a bit warmer.

Tip 3: Seal well

Always close the jar tightly after use to prevent airflow and possible impurities. If you have mayonnaise in the tube, make sure the top is clean and close the cap tightly.  

See more: Can mayonnaise be frozen?


How can you tell if mayo is bad?

Any discoloration or visible appearance of mold is a clear sign of spoilage. Also, a sour smell that is different from the usual is a sign of decay.   

Is it okay to eat expired mayo?

If the jar is unopened, mayo can be good for several months after the expiration date. However, check the contents well when you open the jar. Poor storage conditions can cause spoilage before this time.

Should you refrigerate mayo?

Mayonnaise must be in the refrigerator in any of the following three cases: The mayonnaise was in the fridge in the store / You opened the jar and started using mayonnaise / You made homemade mayonnaise.

How long can mayo sit out?

Opened mayo jar should not be left out unrefrigerated overnight. It might last for a few hours if let sit out. Always check for sign of spoilage before consuming and throw away if unsure.


Mayonnaise is a delicacy addition to any sandwich, salad, or various meat and other dishes. Both children and adults love it, so it is often found as a must-have product in every kitchen.

Mayo will not spoil too quickly if it is purchased. The homemade one will not last longer than a week, but the purchased one can endure even a few months after the expiration date if the package is not opened.

However, if you doubt the correctness of mayonnaise, check all the signs of spoilage and rather throw the product in the trash. Food poisoning and indigestion are possible consequences of consuming lousy mayo.

Finally, if you run out of mayo, you can always find a mayo alternative in your kitchen.

*image by Valentyn_Volkov/depositphotos

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