For commercially prepared mayonnaise, an unopened jar can generally maintain its quality until around the date printed on the package when it has been stored properly.
Once opened, mayonnaise should be kept refrigerated and handled carefully.
A commonly used guideline is to use opened commercial mayonnaise within about two months, although the actual shelf life can vary depending on the product, storage conditions, and how it has been handled.
The printed date is useful information, but it doesn't tell the entire story.
If the jar has been sitting out for long periods, repeatedly exposed to warm temperatures, or contaminated by dirty utensils, its quality and safety can decline more quickly.
What About Homemade Mayonnaise?
Homemade mayonnaise is a different story.
Because homemade mayo often contains raw eggs and doesn't undergo the same processing as commercially produced mayonnaise, it has a considerably shorter refrigerated shelf life.
Homemade mayonnaise should generally be treated as a short-term refrigerator food, rather than something you can keep for weeks.
If you're making mayo at home, using pasteurized eggs can be a useful option, particularly for recipes where the eggs remain uncooked.
Does the Expiration Date Mean Mayo Is Automatically Bad?
Not necessarily.
Food dates can be confusing because different labels can refer to freshness, quality, or manufacturer recommendations.
A “Best By” date, for example, generally relates to expected quality rather than automatically announcing that the food becomes unsafe the following day.
However, that doesn't mean you should ignore dates altogether.
Use the date as one piece of information, then consider:
- Whether the jar has been opened
- How long it has been refrigerated
- Whether it has been stored consistently cold
- Whether the lid and container are intact
- How the mayonnaise looks and smells
- Whether it has been contaminated during use
When you're dealing with a questionable perishable food, it's always better to be cautious.
How to Tell If Mayo Has Gone Bad
Sometimes the easiest answer is right in front of you.
Before using older mayonnaise, take a moment to inspect it.
1. Check the Color
Fresh mayonnaise is usually creamy white or slightly off-white.
If it develops an unusual yellow, brown, gray, or otherwise noticeably altered appearance, it's best to discard it.
A slight change in color can sometimes happen with age, but significant discoloration is a warning sign.
2. Smell It
Fresh mayo has a mild, slightly tangy smell.
If it develops a strong sour, rancid, rotten, or otherwise unpleasant odor, don't taste it to see whether it's still good.
Throw it away.
Your nose can be a useful first warning system for obvious spoilage.
3. Look for Mold
This one is simple.
If you see mold anywhere in the mayonnaise, discard the entire jar.
Don't simply scrape off the visible portion and continue eating the rest.
4. Watch for Major Separation
Some minor separation can occur as mayonnaise ages or after being stored for a while.
However, if the product has developed a strange watery layer, unusual texture, or appearance that doesn't resemble normal mayonnaise, it's worth being cautious.
When significant changes are accompanied by an off smell or other signs of spoilage, discard it.
5. Pay Attention to the Texture
Mayonnaise should have a thick, creamy consistency.
If it becomes unusually lumpy, slimy, curdled, or otherwise looks dramatically different from when you opened it, don't take chances.
Can You Eat Mayo That Was Left Out?
This is one of the most important questions.
Refrigerated mayonnaise shouldn't be left sitting at room temperature indefinitely.
According to USDA food-safety guidance, perishable foods should not remain in the 40°F–140°F (4°C–60°C) danger zone for extended periods.
The general rule is to refrigerate perishable foods within two hours, or within one hour when temperatures are above 90°F (32°C).
That matters especially at picnics, barbecues, parties, and outdoor gatherings.
If a mayonnaise-based salad or sandwich has been sitting outside in hot weather for several hours, don't assume putting it back in the refrigerator will make it safe again.
Why Does Mayo Need Refrigeration After Opening?
Commercial mayonnaise is formulated to be relatively stable, but once the container is opened, handling becomes important.
Every time you open the jar, you potentially introduce food particles, moisture, or microorganisms.
That's why using clean utensils and returning the jar to the refrigerator promptly can help maintain its quality.
Avoid eating directly from the jar and then putting it back in the refrigerator. Cross-contamination can shorten its useful life.
The Best Way to Store Mayonnaise
A few simple habits can help your mayo stay fresh for as long as possible.
Keep It Cold
Store opened mayonnaise in the refrigerator.
The refrigerator should be kept at 40°F (4°C) or below.
Keep the Lid Tightly Closed
Always seal the jar after use.
This helps protect the mayonnaise from odors, contaminants, and unnecessary exposure to air.
Use Clean Utensils
Always scoop mayo with a clean spoon or knife.
Don't put a utensil back into the jar after it has touched raw meat, dirty surfaces, or other foods.
Don't Store It in the Refrigerator Door If You Can Avoid It
The refrigerator door tends to experience more temperature fluctuations than the interior shelves.
Keeping frequently used refrigerated foods in a consistently cold section of the refrigerator can help maintain better storage conditions.
What About Mayo in Potato Salad or Coleslaw?
Once mayonnaise is mixed with other ingredients, the storage situation changes.
Potato salad, macaroni salad, chicken salad, egg salad, and similar dishes should be treated as perishable prepared foods.
Keep them refrigerated and avoid leaving them at room temperature for extended periods.
At a picnic or gathering, serve these dishes in small portions and keep the rest chilled.
The mayonnaise itself isn't necessarily the only concern. Ingredients such as eggs, chicken, potatoes, and other foods can also support bacterial growth when improperly handled.
Can You Freeze Mayonnaise?
Technically, mayonnaise can be frozen, but it's generally not recommended for quality reasons.
Freezing can cause the emulsion to break, resulting in a separated, watery, or curdled texture after thawing.
While you may be able to whisk it back together somewhat, it usually won't have the same smooth consistency.
For that reason, refrigeration is the better choice for preserving opened mayonnaise.
Does Miracle Whip Last as Long as Mayo?
Products such as mayonnaise-style salad dressings can have different formulations, acidity levels, and manufacturer recommendations.
Don't automatically apply the exact same storage timeline to every creamy sandwich spread.
Check the product label and follow its specific storage instructions.
A Simple Mayo Safety Checklist
Not sure whether that half-used jar in the refrigerator is still worth keeping?
Run through this quick checklist:
✓ Was it stored properly in the refrigerator?
✓ Is the container still in good condition?
✓ Has it been open for a reasonable amount of time?
✓ Does it still look normal?
✓ Does it smell normal?
✓ Is there no mold or unusual growth?
✓ Has it been handled with clean utensils?
If several answers make you uncomfortable, don't risk it.
Mayo is inexpensive compared with the consequences of eating spoiled food.
Frequently Asked Questions
How long does opened mayonnaise last in the fridge?
Commercial mayonnaise is commonly recommended for use within about two months after opening when continuously refrigerated and properly handled, although product-specific guidance can differ.
Does unopened mayo need to be refrigerated?
Commercial mayonnaise is generally shelf-stable while unopened, provided the label does not require refrigeration. Once opened, it should normally be refrigerated.
Can mayo go bad in the refrigerator?
Yes. Refrigeration slows spoilage but doesn't stop it indefinitely. Older mayonnaise can eventually develop unpleasant odors, discoloration, mold, or changes in texture.
Can you eat mayo after the best-by date?
A best-by date primarily concerns quality, but you should also consider storage conditions, whether the jar has been opened, and signs of spoilage. When in doubt, discard it.
What happens if mayonnaise is left out overnight?
Mayonnaise that has been left unrefrigerated overnight should generally be discarded, particularly if it has been at room temperature for many hours.
Can you freeze mayonnaise?
You can freeze it, but the texture may separate after thawing. Refrigeration is generally preferable.
How long does homemade mayo last?
Homemade mayonnaise has a much shorter refrigerated shelf life than commercial mayonnaise, particularly when made with raw eggs. Follow the recipe's storage instructions and use it promptly.
The Bottom Line
So, how long does mayo last in the fridge?
For commercial mayonnaise, an opened jar is commonly treated as having a refrigerated life of roughly two months, but there isn't one universal timeline that applies to every product or situation.
The most important factors are proper refrigeration, clean handling, the manufacturer's instructions, and the condition of the mayonnaise itself.
If you notice mold, a strong unpleasant odor, significant discoloration, or an unusual texture, don't try to rescue it.
When you're unsure, it's better to replace the jar than take a chance.
A little attention to storage can keep your mayonnaise fresh, creamy, and ready for everything from sandwiches and burgers to potato salad and homemade dressings.