Yes, mayonnaise can go bad, especially after opening. Keep unopened jars in a cool, dark place for up to 6–12 months past the best-by date. Once opened, refrigerate it immediately and use within 1–2 months. Always store it at 40°F or below, seal tightly, and use clean utensils to prevent contamination. Toss it if you notice odd smells, discoloration, mold, or texture changes. Homemade mayo spoils faster and carries higher risks. There’s more to know about keeping it safe and fresh.
Quick Guide
- Unopened mayonnaise stays safe for 3–6 months past the “best by” date when stored in a cool, dark place.
- Opened mayonnaise lasts 1–2 months in the fridge if kept at or below 40°F and sealed tightly.
- Always refrigerate opened mayo and avoid storing it in the door to maintain consistent cold temperatures.
- Discard mayo if it has a sour smell, mold, discoloration, or lumpy texture—even if within the date range.
- Homemade mayo spoils faster and should be used within 1–2 weeks due to lack of preservatives and raw eggs.
Does Mayonnaise Go Bad? Yes: Here’s When
While it might seem like mayo lasts forever in your fridge, it actually does go bad—especially once you’ve opened the jar.
Use opened store-bought mayo within 1–2 months, or 2–3 months past the Best By date if refrigerated. For best quality, keep it in an airtight container in the coldest part of the fridge to slow bacterial growth.
Discard it if left out over 2 hours, or if you notice odd smells, mold, or texture changes.
Opened mayo should always be refrigerated promptly, as leaving mayo out over two hours increases the risk of bacterial growth and spoilage.
How Long Does Unopened Mayo Last on the Shelf?
You can keep unopened mayonnaise in your pantry for 3 to 6 months past the “best by” date, and sometimes up to a year if stored properly.
To get the most shelf life, store it in a cool, dry place away from heat and sunlight, ideally between 68–72°F. Just like butter, using an airtight container helps prevent absorbing odors from nearby foods.
The airtight seal and acidic ingredients help prevent spoilage, but always check for off smells or discoloration before using.
Commercial mayonnaise remains safe due to pasteurization and preservatives, with unopened jars lasting 6–12 months past the production date under proper conditions pasteurized, sealed.
Shelf Stability Explained
When stored properly, unopened commercial mayonnaise can stay good for months beyond the printed date, often lasting anywhere from 6 to 12 months at room temperature.
Its shelf stability comes from pasteurization, airtight sealing, and acidic ingredients like vinegar that block harmful bacteria.
Preservatives and quality manufacturing also help maintain freshness, keeping your mayo safe and flavorful until opened.
Best-By Date Guidance
Since mayonnaise contains ingredients that resist spoilage, unopened jars typically stay safe and tasty well beyond the best-by date—if stored correctly.
That date marks peak quality, not expiration. You can safely use mayo 3–4 months past the label, though flavor and texture may dip. Always check for odd smells, color changes, or separation. When in doubt, toss it out.
Ideal Storage Conditions
Keep your unopened mayonnaise in a cool, dark spot, and it’ll hold up remarkably well over time.
Store it between 68–72°F, away from heat or sunlight.
Airtight packaging and preservatives prevent spoilage, so don’t open it early.
Properly stored, it lasts 6–12 months past production—sometimes longer—while staying safe and fresh.
Can You Use Mayonnaise After the Best-By Date?
Though best-by dates suggest peak quality, you can usually use mayonnaise after that date if stored properly.
Unopened jars last about a week past the date when kept in the pantry. Once opened, refrigerate immediately and use within one to three months.
For best results, keep it in an airtight container to help maintain freshness. Always check for off smells, color changes, or mold—discard if present.
How to Tell If Mayo Has Gone Bad (And When to Toss It)
If you’ve ever opened a jar of mayonnaise and hesitated over a strange color or smell, you’re not alone—spotting spoiled mayo isn’t always obvious, but knowing what to look for can save you from foodborne illness.
Check for color changes, mold, or a sour smell. If it’s lumpy, separated, or smells off, toss it.
Never taste moldy mayo—discard the whole jar.
After opening, store mayo in a cool, dark spot and keep it tightly sealed to limit oxidation effects that can speed quality loss.
How Long Does Opened Mayo Last in the Fridge?
Once you crack open a jar of mayonnaise, its shelf life starts ticking down, so it’s important to know how long it stays safe and fresh in the fridge.
Store-bought mayo lasts about 2 months after opening if kept at 40°F or below.
Always seal it tightly, use clean utensils, and store it away from the fridge door to prevent spoilage and bacterial growth.
Like soy sauce, factors like exposure to air can accelerate deterioration, so minimizing time uncapped helps preserve quality.
Is Homemade Mayo Riskier Than Store-Bought?
You’re taking a bigger risk with homemade mayo because it usually lacks the preservatives and pasteurization that keep store-bought versions safe for months.
If you use raw eggs, especially non-pasteurized ones, you could be exposing yourself to salmonella, particularly if your immune system isn’t strong.
While homemade mayo tastes fresher, you’ll need to eat it quickly and know the safety trade-offs.
Lack Of Preservatives
While homemade mayonnaise boasts a fresher taste and cleaner ingredient list, skipping preservatives means you’re trading shelf life for simplicity.
You’ll need to refrigerate it immediately and use it within 1–2 weeks.
Without stabilizers, it spoils faster and can break if not handled right.
Store-bought lasts longer thanks to additives, but homemade gives you control over what goes in it.
Raw Egg Concerns
Because homemade mayonnaise often skips the key safety step of acidification, it can pose a higher risk than store-bought versions—especially when raw eggs are involved.
You’re more exposed to *Salmonella* and other pathogens since home recipes usually lack the acid levels needed to kill bacteria.
Store-bought mayo uses controlled acidification, making it safer.
If you make it yourself, add acid, keep it cold, and eat it quickly.
Wrapping Up
Yes, mayonnaise can go bad, but it usually lasts longer than you think. Keep unopened mayo in a cool, dry place and use it within 3–4 months past the best-by date. Once opened, store it in the fridge and toss it after 2 months. Check for odd smells, color changes, or mold—when in doubt, throw it out. Homemade mayo spoils faster, so refrigerate it and use within a week.
