How Long Homemade Mayo Stays Fresh in Your Refrigerator

Homemade mayo lasts 1 to 2 weeks in the refrigerator

Homemade mayonnaise keeps for about 7 to 14 days when stored in an airtight container at 40°F or below. The exact timeframe depends on how fresh your eggs were when you made it, whether you added acid (lemon juice or vinegar), and how carefully you handle it after opening. Store-bought mayo lasts much longer—often 2 to 3 months—because manufacturers add preservatives and pasteurize the eggs. Homemade versions have none of that protection, so the clock starts ticking the moment you finish blending.

The main risk with homemade mayo is bacterial growth, particularly from raw or lightly cooked eggs. Even though the acidic ingredients (lemon juice or vinegar) create an environment where harmful bacteria struggle to grow, they don't eliminate the risk entirely. Temperature control is your strongest defense: keep your mayo at a steady 40°F or colder, and never leave it on the counter for more than 2 hours.

Key Takeaways

• Homemade mayo stored in an airtight container at 40°F or below lasts 1 to 2 weeks, while store-bought versions last 2 to 3 months because of added preservatives.
• The acidity from lemon juice or vinegar slows bacterial growth but does not eliminate risk, so temperature control matters more than the recipe itself.
• Always use clean utensils when scooping mayo, and never double-dip or leave it sitting out at room temperature for more than 2 hours.
• Signs of spoilage include off odors, visible mold, separation of oil and liquid, or a sour taste—discard immediately if you notice any of these.
• Using pasteurized eggs instead of raw eggs extends shelf life slightly and reduces food safety risk, though homemade mayo will still expire faster than commercial versions.

Why homemade mayo spoils faster than store-bought

Commercial mayonnaise contains preservatives like potassium sorbate and sodium benzoate that inhibit mold and bacterial growth. Manufacturers also pasteurize their eggs, which kills pathogens before they ever enter the jar. When you make mayo at home with raw eggs and no added preservatives, you're relying entirely on the acidity of your lemon juice or vinegar to keep bacteria in check. That acid works—it lowers the pH enough to slow growth—but it's not a complete barrier.

The emulsion itself (the way oil and egg yolk blend together) also matters. A stable emulsion keeps the ingredients from separating, which would expose more surface area to air and bacteria. If your mayo breaks or separates during storage, it's no longer safe to eat, even if it hasn't reached the 2-week mark. This is why technique matters: a well-made emulsion stays stable longer than a loose or grainy one.

Storage containers and temperature control

Store homemade mayo in a glass or food-grade plastic container with an airtight lid. Glass is ideal because it doesn't absorb odors or flavors and doesn't leach chemicals. Make sure the lid seals tightly—any air gap allows bacteria to enter and moisture to escape, which can cause the mayo to dry out or develop off-flavors. Never store mayo in an open bowl or covered loosely with plastic wrap.

Keep your refrigerator at 40°F or below, and place the mayo on a shelf rather than in the door. Refrigerator doors experience temperature fluctuations every time you open them, which can speed spoilage. A shelf in the main body of the fridge stays at a more consistent temperature. If you live in a warm climate or your refrigerator runs warmer than average, your mayo may not last the full 2 weeks—check it more frequently for signs of spoilage.

How to tell when homemade mayo has gone bad

Discard homemade mayo immediately if you notice any of these signs: a sour, rancid, or off smell; visible mold or discoloration; a slimy texture; or separation of oil and liquid that doesn't recombine when stirred. A sour smell is the most reliable indicator—it means acid-producing bacteria have colonized the mayo. Don't taste it to check; smell is enough.

Separation is common in homemade mayo and doesn't always mean it's spoiled, but it does mean the emulsion has broken down. If the mayo separates and smells fine, you can try whisking it back together with a small amount of water or lemon juice. If it won't recombine or if it smells off, throw it out. When in doubt, discard it—the cost of a batch of mayo is far less than the risk of foodborne illness.

Using pasteurized eggs to extend shelf life

If you're concerned about food safety or want your mayo to last slightly longer, use pasteurized eggs instead of raw ones. Pasteurized eggs have been heat-treated to kill pathogens without cooking the egg solid. They're available at most grocery stores in the regular egg section and cost only slightly more than standard eggs. Pasteurized eggs reduce the risk of salmonella and may extend shelf life by a few days because there are fewer bacteria present to begin with.

Even with pasteurized eggs, homemade mayo still won't last as long as store-bought versions because you're not adding chemical preservatives. But pasteurized eggs are a good middle ground if you want the taste and texture of homemade mayo with a bit more safety margin. Some recipes also call for pasteurized egg yolk specifically, which you can find in liquid form in the baking aisle.

Handling and cross-contamination risks

Every time you open the mayo jar, you introduce bacteria from the air and from whatever utensil you use to scoop it out. Always use a clean spoon or knife, and never double-dip—don't use the same utensil to scoop mayo and then dip it back into the jar after it's touched other food. This introduces bacteria directly into the container. If you're making sandwiches for multiple people, scoop the mayo into a small dish first, then let people use their own clean utensils.

Wash your hands before handling the mayo jar, and wipe the outside of the jar and lid with a clean cloth before storing it. If the lid or rim gets sticky or contaminated, clean it thoroughly before closing. These small habits significantly reduce the risk of introducing spoilage organisms into the jar.

Making mayo in smaller batches

One practical approach is to make smaller batches of mayo more frequently rather than one large batch that sits in the fridge for 2 weeks. A batch made from one egg yolk yields about 1 cup of mayo, which is enough for a week of typical use. Making fresh mayo every 7 to 10 days means you're always eating it at its peak freshness, and you don't have to worry as much about the exact storage date.

Smaller batches also reduce waste if something does go wrong—a broken emulsion or contamination affects only 1 cup instead of 2 or 3. The time investment is minimal (mayo takes about 5 minutes to make once you have the technique down), and the flavor difference between fresh and 2-week-old mayo is noticeable. If you make mayo regularly, this approach often feels easier than trying to track storage dates.

Frequently Asked Questions

Can I freeze homemade mayo to make it last longer?

Freezing is not recommended for homemade mayo. The emulsion breaks down when frozen because the oil and water separate as ice crystals form. When you thaw it, the mayo will be grainy and unusable, even if it's technically safe to eat. Refrigeration is your only reliable storage method for homemade mayo.

What if I added extra lemon juice or vinegar to my mayo—does that make it last longer?

Extra acid does slow bacterial growth slightly, but it won't dramatically extend shelf life. The trade-off is that too much acid makes the mayo taste sour and changes the texture. Stick to standard recipe proportions (about 1 tablespoon of lemon juice or vinegar per egg yolk). The main factor in shelf life is still temperature control, not acid content.

Is it safe to eat mayo that's been left out on the counter overnight?

No. Homemade mayo should not sit at room temperature for more than 2 hours. After that, bacteria multiply rapidly. If your mayo has been left out overnight, discard it. This applies even if it smells fine—bacteria can grow without producing obvious odors.

Can I tell if mayo is safe by tasting a tiny bit?

No. Never taste mayo to check if it's safe. Harmful bacteria like salmonella don't always produce noticeable flavors or smells. Use your nose and eyes: if it smells off or looks discolored, throw it out. If it looks and smells fine but you're unsure about the storage date, err on the side of caution and discard it.

Does adding oil or water to fix separated mayo affect how long it lasts?

If you successfully re-emulsify separated mayo by whisking in a small amount of water or lemon juice, the shelf life doesn't change—it's still the same age as when you made it. However, if the separation happened because bacteria broke down the emulsion, re-emulsifying won't make it safe. Only attempt to fix separation if the mayo smells fine and looks normal otherwise.