Can you eat mayonnaise from a jar that has been open for several weeks or months?

Whether homemade or industrial, mayonnaise is the perfect accompaniment for a multitude of dishes. Prepared with simple ingredients like egg, oil and vinegar, it is popular with gourmands of all ages. Easy to make, it can also be purchased ready to eat in supermarkets. But once mayonnaise is made, how long can it be stored? Here’s everything you need to know to avoid unpleasant surprises.

Opinions differ on the shelf life of homemade mayonnaise. While some estimate that it can be consumed up to a week after preparation, the French Food Safety Agency (AFSSA) recommends limiting this period to 24 hours. This precaution is essential to avoid health risks. It is therefore crucial to store your mayonnaise in an airtight container in the refrigerator, at a temperature lower than or equal to 4°C. For catering professionals, the Guide to Good Hygiene Practices recommends the same rigor.

Industrial mayonnaise, purchased in a tube or jar, offers a much longer shelf life. After opening, it can be consumed for up to 10 weeks, provided you note the date of opening on the label to avoid confusion. However, even once the use-by date has been reached, if the jar has not been opened, it is possible to slightly extend its use. That said, you should always be alert to the appearance of strong odors or mold, undeniable signs that the mayonnaise is no longer edible.

To extend the shelf life of your homemade mayonnaise, add a splash of lemon or vinegar. These acidic ingredients help keep it fresh for another day. However, freezing mayonnaise is not recommended because it affects its texture and can encourage the proliferation of bacteria. When in doubt, it is always better to be careful and not consume suspect mayonnaise.