Mayonnaise is one of those kitchen staples that seems to live in the refrigerator forever. You open a jar, use a few spoonfuls for sandwiches or a salad, put it back in the fridge, and sometimes completely forget when you first opened it.
Then one day, you reach for it and wonder: Is this still good?
Knowing how long mayonnaise lasts can help you avoid unnecessary waste while also making safer choices in the kitchen. For commercially prepared mayonnaise, USDA guidance recommends keeping it refrigerated after opening and using it within about 2 months.
But the date on the jar isn’t the only thing that matters. How the mayonnaise was stored, how it was handled, and whether there are visible or noticeable changes can all help you decide whether it’s time to replace it.
How Long Does Mayonnaise Last After Opening?
For commercial mayonnaise, the general refrigerator guideline is about 2 months after opening when properly refrigerated.
That doesn’t mean every jar suddenly becomes unsafe on day 61. Storage recommendations are guidelines rather than guarantees, and the manufacturer’s instructions should always be followed when they are more specific.
The safest approach is to keep track of when you opened the jar and store it correctly from that point forward.
If you can’t remember when you opened it and it has been sitting in the refrigerator for a very long time, replacing it is usually the better choice.
What About an Unopened Jar?
An unopened commercial mayonnaise jar generally has a considerably longer storage life than an opened one.
The printed date on an unopened container is important, but it should be interpreted according to the type of date and the manufacturer’s storage instructions.
Once the jar is opened, however, refrigeration becomes especially important.
The USDA notes that commercial mayonnaise should be refrigerated after opening and gives approximately two months as the refrigerator storage guideline.
Why Does Mayonnaise Last So Long?
Mayonnaise has an interesting combination of ingredients.
Commercial mayonnaise typically contains oil, eggs or egg products, and an acidic ingredient such as vinegar or lemon juice. The formulation and acidity help give commercially produced mayonnaise a relatively long shelf life compared with many homemade foods.
However, “long-lasting” doesn’t mean “permanent.”
Once the container is opened, it is exposed to air, utensils, and the surrounding kitchen environment. Repeated handling can also introduce food particles and microorganisms into the jar.
That’s why proper storage and clean handling matter.
How Should You Store Mayonnaise?
The simplest rule is:
Keep opened mayonnaise refrigerated and tightly covered.
Your refrigerator should be kept at 40°F (4°C) or below for proper cold storage.
It’s also a good idea to:
- Keep the lid tightly closed.
- Return the jar to the refrigerator promptly after using it.
- Use clean utensils.
- Avoid dipping utensils that have touched other foods directly into the jar.
- Keep the rim and lid clean.
- Don’t leave the jar sitting on the counter during lengthy meal preparation.
These habits help maintain the quality of the mayonnaise and reduce opportunities for contamination.
The Refrigerator Door Isn’t Always the Best Spot
Many people automatically store mayonnaise in the refrigerator door because that’s where condiment shelves are located.
It’s convenient, but the refrigerator door experiences more temperature changes than the interior shelves because it is opened frequently.
For better temperature stability, keeping mayonnaise toward the colder interior portion of the refrigerator can be a sensible option.
The most important thing, however, is maintaining the refrigerator at 40°F (4°C) or below.
How Can You Tell If Mayo Has Gone Bad?
Sometimes the jar’s age isn’t the only clue.
You may notice changes in appearance, smell, or texture that indicate the mayonnaise should no longer be used.
1. An Unusual Smell
Fresh mayonnaise naturally has a slightly tangy aroma because of its acidic ingredients.
But if it develops a distinctly sour, rancid, fermented, or otherwise unpleasant odor that is different from its normal smell, don’t use it.
A strange smell is a good reason to discard the jar.
2. Mold
Visible mold is an obvious reason to throw the mayonnaise away.
Don’t simply scrape off the affected portion and continue using the rest.
When mold is visible on a moist food, the safest choice is to discard the product.
3. Major Color Changes
Mayonnaise is normally pale and creamy.
If you notice unusual darkening, browning, or another significant color change, it’s better to discard it.
4. Unusual Texture
Some minor separation can occur in certain products and doesn’t necessarily mean spoilage.
However, if the mayonnaise develops a strange texture, becomes unusually watery, lumpy, or otherwise looks significantly different from when it was fresh, take that as a warning sign.
5. A Bloated or Damaged Container
If the container appears swollen, damaged, or otherwise abnormal, don’t taste the mayonnaise to investigate.
When food packaging looks unusual, it’s better to err on the side of caution.
Don’t Taste Mayo to Test It
This is an important kitchen rule.
If you’re uncertain whether mayonnaise is still good, don’t take a small taste just to find out.
Spoilage isn’t always something you can reliably detect by taste, and deliberately tasting questionable food isn’t worth the risk.
Instead, consider the storage history, appearance, smell, and manufacturer’s instructions.
When you’re genuinely unsure, throwing it away is the safest choice.
What If Mayo Was Left Out?
This is where the storage history becomes especially important.
A jar that has been properly refrigerated is very different from one that has spent hours sitting on a warm countertop.
The general food-safety rule is to avoid leaving perishable foods at room temperature for extended periods. Food left out for more than 2 hours, or more than 1 hour when temperatures are above 90°F (32°C), should generally be discarded.
If mayonnaise has been sitting outside the refrigerator for a long time, don’t simply put it back in the fridge and assume it has been reset.
What About Homemade Mayonnaise?
Homemade mayonnaise is a different situation from commercially produced mayonnaise.
The ingredients, preparation method, acidity, and whether pasteurized eggs are used can all affect its storage life.
Because homemade mayonnaise doesn’t necessarily have the same formulation and processing as commercial products, you shouldn’t automatically apply the commercial two-month guideline to it.
If you make mayonnaise at home, follow a tested recipe’s specific refrigeration and storage instructions.
What About Mayo-Based Salads?
There’s another important distinction between mayonnaise itself and foods made with mayonnaise.
Chicken salad, tuna salad, egg salad, macaroni salad, and similar prepared dishes have their own storage limits.
The USDA lists store-prepared or homemade egg, chicken, ham, tuna, and macaroni salads at approximately 3–5 days in the refrigerator.
So a jar of mayonnaise may last much longer than a bowl of chicken salad made with that mayonnaise.
This is why you shouldn’t assume that adding mayonnaise to another food gives the finished dish the same shelf life as the unopened condiment.
Can You Freeze Mayonnaise?
Freezing mayonnaise isn’t generally recommended.
The USDA storage guidance lists commercial mayonnaise as a product that doesn’t freeze well.
Because mayonnaise is an emulsion, freezing and thawing can affect its texture and cause the ingredients to separate.
Even if the thawed product isn’t necessarily dangerous simply because it was frozen, the quality may be noticeably worse.
For that reason, the refrigerator is the better place to store mayonnaise.
How to Make Your Mayo Last Longer
You don’t need any complicated tricks.
Good storage habits are enough.
Keep the Lid Clean
After using mayonnaise, wipe the jar’s rim if necessary before closing the lid.
A clean rim helps prevent dried food from accumulating around the opening.
Use Clean Utensils
Don’t use a spoon that has already touched chicken, meat, vegetables, bread, or another prepared food and then place it back into the mayonnaise jar.
That can introduce unwanted contaminants into the container.
Don’t Leave It Out
Take out the amount you need and return the jar to the refrigerator rather than leaving it on the counter throughout the meal.
Write Down the Opening Date
If you’re someone who frequently wonders how old your condiments are, a simple trick can help.
When you open a new jar, write the date on the lid with a food-safe marker.
That tiny habit can save you from guessing months later.
A Simple Mayo Storage Guide
Here’s an easy reference:
| Situation | General guidance |
|---|---|
| Commercial mayonnaise, unopened | Follow the package date and storage instructions |
| Commercial mayonnaise, opened | About 2 months refrigerated |
| Homemade mayonnaise | Follow the specific recipe’s storage guidance |
| Mayo-based chicken/egg/tuna salads | About 3–5 days refrigerated |
| Frozen mayonnaise | Not recommended for quality |
The two-month figure for opened commercial mayonnaise comes from USDA/FSIS storage guidance.
Frequently Asked Questions
Does mayonnaise need to be refrigerated?
After opening, commercial mayonnaise should generally be refrigerated. USDA guidance recommends refrigeration and gives approximately two months for opened commercial mayonnaise.
Can I use mayonnaise after the two-month mark?
The two-month period is a storage guideline, not a magical expiration point. However, if the mayonnaise has been open for substantially longer, especially if you don’t know how it was stored, replacing it is the safer choice.
Does mayonnaise expire in the refrigerator?
Yes. Refrigeration slows deterioration but doesn’t make mayonnaise last indefinitely.
Can I freeze mayonnaise?
It’s generally not recommended because freezing can negatively affect its texture and cause separation.
Is separated mayonnaise automatically bad?
Not necessarily. Some separation can occur depending on the product and storage conditions. However, significant changes in texture combined with an unusual smell, color, or other spoilage signs are reasons to discard it.
What temperature should my refrigerator be?
For proper cold storage, keep your refrigerator at 40°F (4°C) or below.
Final Thoughts
Mayonnaise may seem like one of those foods that can sit in the refrigerator indefinitely, but it still deserves a little attention.
For commercial mayonnaise that has been opened and properly refrigerated, about two months is the standard USDA storage guideline.
Keeping the jar cold, closing it properly, using clean utensils, and avoiding prolonged time at room temperature can all help preserve its quality.
And when you open an old jar and aren’t sure whether it’s still good, don’t rely on a tiny taste to make the decision. Check how long it has been open, consider how it was stored, look for unusual changes, and follow the manufacturer’s instructions.
Sometimes the easiest food-safety decision is also the best one: if you’re genuinely unsure, replace the jar rather than taking a chance.
