Does Mayonnaise Go Bad?

Does mayonnaise go bad? You might find yourself asking this question as you prepare your lunch sandwich and begin to wonder just how long that jar of mayo has been in the fridge. The answer is of course that all mayo eventually goes bad, but there are many factors to consider when determining if this has occurred yet.

How To Tell If Mayonnaise Is Bad

Here are some signs that can help you determine if your mayonnaise has reached the end of its shelf life. If the mayo is giving off a putrid smell or smells acidic, it is a likely sign that it has spoiled. Another sign is if the color of the condiment has changed considerably since opened. It could be a darker shade of white or even have developed into a brownish-yellow color. Of course, the appearance of mold or spores is a definite sign that your mayonnaise is ready for the trash can[1].

The Difference In Commercial And Homemade Mayonnaise

The first steps to determining if your mayonnaise has gone bad is identifying if it was store-bought or homemade. Since homemade mayonnaise is made using raw eggs, unlike commercial mayonnaise, which uses pasteurized eggs, it tends to go bad long before its commercial counterpart. Homemade mayonnaise has a refrigerated spoiling time of about one to two weeks whereas store-bought mayonnaise can be kept in the refrigerator for up to two months after being opened[2].

Does Mayonnaise Go Bad?
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Proper Storage Of Mayonnaise

Unopened jars of mayonnaise should be kept at room temperature in a dry area such as a pantry. It can be kept unopened in this way until the date printed on the Use By label. It should be discarded after this date has passed. Use By dates vary by manufacturer especially considering the fact of whether or not preservatives are being used. Always be sure to check the expiry date before using.

Opened jars of mayonnaise should be kept refrigerated when not in use. Opened jars should be discarded after two months of refrigeration to ensure the best taste and safest consumption.

Mayo that has already been spread on a sandwich or contained in a dish such as macaroni salad should be eaten within the hour unless the sandwich or dish has been refrigerated. Any dish or sandwich with mayonnaise already spread or contained within it should be eaten within 3 days of refrigeration[3].

Factors That Could Cause Mayonnaise To Spoil Before Expiration Date

There are other factors besides time that can spoil your mayonnaise before the date printed on the package.

The most common cause of contamination is using utensils that may be spoiled with food contaminates such as breadcrumbs or tuna. These contaminates can cause bacterial growth which will certainly cause the mayonnaise to become harmful to consume. Always use clean utensils to distribute your mayonnaise. Plastic utensils may even be used to help stop cross contamination. Never “double dip” your utensil. For Example spreading mayo onto your tuna fish and then deciding that you want more mayo and using the same utensil to dip out more mayo onto your tuna. This causes contamination. If you decide, you want more, simply wash off the utensil and then dispense more mayonnaise onto your tuna. Another way to be safe about contamination is to buy the squeeze bottles of mayonnaise that are readily available in most mayonnaise brands today. Just be sure not to touch the opening to any of your sandwiches or dishes[4].

Improper food storage such as exposure to extreme heat or prolonged absence of refrigeration after opening can also contribute to spoilage. Always store unopened jar of mayonnaise at room temperature in a dry place such as a pantry or cabinet to ensure food safety. Refrigerate opened mayo immediately after use and keep it there for up to two months remembering to promptly return the jar to refrigerator when not in use.

Brownish mayonnaise giving off that putrid smell that has gone three months over its sell-by date is definitely bad. Pitch it in the trash and try to remember the safety tips such as refrigerate after opening and avoiding cross contamination and your next jar may fair a bit better tasting than the previous. One that is certain is that mayonnaise does go bad, but you can identify and help prolong its life by remembering its proper storage and use.