How Long Can You Keep Mayonnaise In The Fridge? | Fridge Day

Opened store-bought mayonnaise keeps its best taste in the fridge for about 2 months when kept at 40°F/4°C or colder and handled cleanly.

You open a jar, make a sandwich, put it back, then weeks fly by. Later you spot the mayo and wonder if it’s still a good call. The tricky part is that mayonnaise can look fine long after it stops tasting fresh. You want a simple rule, plus a few checks that catch the “toss it” situations fast.

For most homes, treat opened, store-bought mayo as a 2-month fridge item. If your fridge runs warm or the jar gets messy, shorten that window.

What changes once you open the jar

Unopened commercial mayonnaise is sealed, acidic, and made with pasteurized ingredients. Once you break the seal, air, utensils, and temperature swings start to matter more.

Each scoop can move crumbs or tiny bits of food into the jar. That speeds up spoilage and flavor fade, even when the mayo still looks fine.

Fridge temperature does the heavy lifting

Mayonnaise lasts longer when your refrigerator stays at or below 40°F (4°C). If you’re not sure, stick a fridge thermometer on the middle shelf for a day. Door shelves run warmer from frequent opening, so they’re the easiest place to lose days without noticing.

How long can you keep mayonnaise in the fridge? Shelf-life by type

Different “mayo” products behave differently. The base ingredients, the amount of acid, and whether the product is homemade all change the usable window. Use the ranges below as a fridge planning tool, then use your senses when you’re near the edge.

Two official tools that are handy for cold storage planning are the Cold Food Storage Chart and the FoodKeeper app, both published through FoodSafety.gov.

The FDA’s printable Refrigerator & Freezer Storage Chart is handy when you’re building a fridge “use-first” routine.

Store-bought mayo (opened)

Plan on about 2 months for best taste when the jar stays cold and you keep it clean. Once you pass that mark, you’ll often notice flavor flattening, a less creamy mouthfeel, and more separation.

Store-bought mayo (unopened)

Unopened mayo can sit in a cool cupboard until the date on the label. That date is about taste and texture. If the jar was stored hot (next to an oven, in a sunny spot, in a warm garage), treat that as extra wear and shorten how long you keep it after opening.

Homemade mayonnaise and aioli

Homemade mayo is in a different lane. It often uses raw egg, less acid, and has no commercial preservatives. If you make it at home, keep it refrigerated and plan to use it within a few days. If you’re not sure whether your recipe fully acidifies the mixture, keep the time short.

Mayo-based salads and dips

Potato salad, chicken salad, egg salad, coleslaw, ranch-style dips, and tuna salad are not “just mayo.” They’re mixed foods with extra moisture and extra protein, so they spoil sooner. Many cold storage charts group prepared salads with short fridge windows. If you meal prep these, date the container and keep the time tight.

If your dish sat out on the counter, use FoodSafety.gov’s food safety time and temperature guidance as a baseline: perishable foods shouldn’t sit at room temperature for long stretches. For picnics and buffets, keep mayo dishes over ice and return leftovers to the fridge fast.

Use the first table as your fridge cheat sheet.

Item	Fridge time (40°F/4°C or colder)	Notes
Commercial mayonnaise, opened	Up to 2 months	Best taste inside the window; keep lid clean and jar cold.
Commercial mayonnaise, unopened	Not needed until opened	Store cool and dry; refrigerate after opening for quality.
Light mayo or reduced-fat mayo, opened	About 1–2 months	Higher water content can dull flavor sooner; watch separation.
Vegan mayo, opened	About 1–2 months	Check label; plant emulsions can thin over time.
Mayo squeeze bottle, opened	Up to 2 months	Less utensil contact helps; wipe the nozzle after use.
Homemade mayo	3–4 days	Short window; keep covered, cold, and use clean tools.
Chicken salad, tuna salad, egg salad	3–5 days	Date the container; toss if it smells off or gets watery.
Potato salad or coleslaw (homemade)	3–5 days	Shorter if it sat out; keep chilled during serving.
Jar used at the table (frequent warm time)	Shorten by 1–2 weeks	Repeated warm-ups speed flavor fade and spoilage odds.

How to tell if mayonnaise has gone bad

Mayonnaise spoilage is often subtle at first. You’re looking for a change that feels “off,” not a tiny difference that you can talk yourself out of. If you see any of the red flags below, it’s not worth pushing your luck.

Smell check

Fresh mayo smells mild and slightly tangy. Bad mayo smells sharp, sour in a way that stings, or rancid like old cooking oil. If the smell makes you pause, toss it.

Look check

A little separation can happen even in good mayo, especially after a long fridge sit. Stirring back to creamy can be fine. What’s not fine is visible mold, pink or dark specks, or a surface film that looks fuzzy or slimy.

Texture and taste check

Mayo should feel thick and smooth. If it turns watery, stringy, or gritty, it’s past its prime. If you do a tiny taste test and the flavor is bitter, metallic, or “paint-like,” spit it out and bin the jar.

When the label date matters

Use-by and best-by dates are quality tools. They’re most helpful for unopened jars. Once opened, your calendar starts to matter more than the printed date. If you opened a jar months ago and can’t remember when, treat it as overdue.

Storage habits that keep mayo fresh longer

Most “mayo goes bad early” stories trace back to handling, not the product itself. Small habits add days, sometimes weeks.

Keep it cold in the main part of the fridge

Middle shelves tend to hold steadier temperatures than the door. If your fridge is packed, keep the jar where air can still circulate. Avoid parking it against the back wall where it can partially freeze in some refrigerators, which can split the emulsion.

Use clean tools every time

No double-dipping. If a knife touched bread, deli meat, or a sandwich, rinse it before going back into the jar. If you’re making a big batch of something, spoon mayo into a bowl first, then mix from the bowl. That keeps the jar cleaner for the rest of the month.

Wipe the rim and lid

Mayo build-up around the rim holds crumbs and dries into a crust that can grow mold. A quick wipe with a clean paper towel after you scoop prevents most of that mess.

Write the open date

Put a small piece of tape on the jar and write the date you opened it. It takes ten seconds and removes the “guessing game” later. If you don’t want tape, write the date on the lid with a marker.

When mayo is in a mixed dish

This is where people get tripped up. A mayo jar is one thing. A mayo-based salad with chopped eggs, chicken, or seafood is another. Those proteins bring their own spoilage clocks, and cutting and mixing adds surface area where bacteria can grow.

Meal prep timing that works

If you prep chicken salad or tuna salad for lunches, make a batch for 2–3 days, not a full work week. Store it in shallow containers so it chills fast. Keep the fridge at 40°F/4°C or colder and avoid leaving the container on the counter while you portion meals.

Serving timing that works

For parties, set out a smaller bowl and keep the main batch in the fridge. Refill the bowl as needed. If the bowl sat out for a long time, don’t pour leftovers back into the main container.

The table below helps you decide fast when you’re staring at a jar or a container and trying to make a call.

What you notice	What it points to	What to do
Rancid, “old oil” smell	Oil has oxidized; flavor and quality are gone	Toss the jar
Mold spots on lid or surface	Contamination on exposed areas	Toss the jar, clean the fridge spot
Pink tint, dark specks, or slimy film	Microbial growth	Toss the jar
Watery layer on top	Emulsion weakening from age or temperature swings	Stir and smell; if taste is dull, replace
Lid rim crusty with crumbs	Frequent utensil contact and drying	Wipe now; shorten keep time
Jar was left out overnight	Extended warm time for a perishable food	Discard to be safe
Mayo-based salad smells sour	Prepared food has turned	Discard the whole container
You can’t recall the open date	Time uncertainty	If it’s been weeks, replace it

Smart ways to use up a jar

If you want to finish a jar inside its best window, these ideas use small amounts at a time.

• Simple dressing: Whisk mayo with lemon juice, salt, pepper, and a splash of water.
• Grilled cheese browning: A thin swipe on bread browns evenly in a skillet.
• Tuna mix: Stir in chopped pickles or celery for crunch.

If you use mayo only now and then, smaller jars usually fit your fridge habits better.

A simple fridge rule you can stick with

When your jar is store-bought and opened, aim to finish it inside 2 months, keep it cold, and keep it clean. If it smells off, looks odd, or you can’t recall when it was opened, replace it. With mayo-based salads, keep the time shorter and treat “sat out” leftovers as a no-go.