Mayonnaise is a staple condiment in many refrigerators. It’s great for spreading on sandwiches, using as a base for dips and dressings, and adding flavor and moisture to dishes. However, mayonnaise can go bad if not stored properly. Eating spoiled mayonnaise can cause food poisoning, which leads to unpleasant symptoms like nausea, vomiting, and diarrhea. So how do you know if your mayonnaise has gone bad?
Check the Expiration Date
The first thing to look for is the expiration date printed on the mayonnaise jar. This will give you an idea of how long the mayonnaise should last after opening. Once opened, mayonnaise will typically stay good for 2-3 months. If your mayonnaise is past the printed expiration date, it’s best to throw it out.
Examine the Color
Fresh mayonnaise should be creamy white in color. As mayonnaise starts to spoil, it will start to darken and possibly take on a yellowish tint. Grayish, brownish, or yellowish mayonnaise is a sign that it has spoiled and should be discarded.
Check the Smell
Give your mayonnaise a sniff test. Fresh mayonnaise has a rich, eggy, and acidic smell. If the mayonnaise smells sour, funky, or rotten, it has likely spoiled and should not be eaten.
Look for Texture Changes
The texture of mayonnaise can also indicate spoilage. Unopened mayonnaise should be thick with a smooth, creamy texture. As it starts to spoil, it will become more watery and thin, almost separating back into oil and vinegar. Spoiled mayonnaise may also be lumpy or grainy in texture.
Examine the Surface
Check the surface of the mayonnaise inside the jar. Look for any mold, thinning, water separation, or oil spots. These are indications that bacteria has started to grow and the mayonnaise is past its prime.
Mind Proper Storage
To get the longest shelf life out of your mayonnaise, proper storage is key. Keep mayonnaise tightly sealed in the refrigerator after opening. The cold temperature keeps bacteria growth to a minimum. Only keep mayonnaise for 2-3 months after opening, even if the expiration date is further out. Make sure to scoop mayonnaise out with a clean utensil each time to prevent introducing bacteria into the jar.
Practice Food Safety
There are a few general food safety practices that can minimize the chances of your mayonnaise going bad prematurely:
- Keep mayonnaise refrigerated at 40°F or below
- Store mayonnaise towards the back of the fridge where temperature is most consistent
- Keep mayonnaise tightly sealed in its original jar
- Don’t let mayonnaise sit out at room temperature for more than 2 hours
- Discard mayonnaise 2-3 months after opening
- Use clean utensils each time when scooping mayonnaise
- Don’t add fresh mayonnaise to a jar that already has some leftover
- Purchase mayonnaise from reputable brands and check for quality seals
- Check expiration date and don’t purchase mayonnaise that is close to expiring
- Clean refrigerator regularly to prevent bacterial growth
What If I Eat Spoiled Mayonnaise?
If you accidentally ingest mayonnaise that has spoiled, the most common side effect is food poisoning. Symptoms of food poisoning include:
- Nausea
- Vomiting
- Stomach cramps
- Diarrhea
- Fever
- Chills
- Headache
- Fatigue
- Body aches
In healthy adults, food poisoning from mayonnaise will typically resolve on its own in 24-48 hours. Stay hydrated and get plenty of rest. Seek medical treatment if symptoms are severe or persist longer than 48 hours.
Certain groups have a higher risk of developing dangerous complications from food poisoning. This includes young children, pregnant women, the elderly, and those with weakened immune systems. If you are in a high risk group and experience food poisoning symptoms after consuming spoiled mayonnaise, seek medical care promptly.
How to Store Mayonnaise Safely
Here are some top food safety tips for maximizing your mayonnaise’s shelf life:
Refrigerate after Opening
Keep mayonnaise chilled at 40°F or below after opening. The cool temperature prevents bacterial growth. Store opened mayonnaise towards the back of the refrigerator where the temperature is most consistent.
Use Clean Utensils
Always use clean utensils when scooping mayonnaise. Never re-dip a dirty spoon back into the jar. This can introduce bacteria and shorten the mayonnaise’s shelf life.
Keep Lid Tightly Sealed
After each use, firmly press the lid back onto the mayonnaise jar to create a tight seal. This prevents air from entering and bacteria from contaminating the contents.
Don’t Store at Room Temperature
Avoid leaving mayonnaise jars out on the counter or anywhere at room temperature. Bacteria can thrive and multiply rapidly at temperatures above 40°F.
Watch for Expiration Date
Check the expiration or “best by” date printed on the mayonnaise jar. Consume opened mayonnaise within 2-3 months for best quality and safety.
Check for Signs of Spoilage
Inspect opened mayonnaise periodically for changes in color, texture, and smell that indicate spoilage. Discard at first signs of spoilage.
Shop Safely
When shopping, pick up refrigerated mayonnaise last. Inspect jars for damage or broken seals. Check expiration dates and choose jars with the latest dates.
Keep Refrigerator Clean
Clean your refrigerator regularly to remove harmful bacteria that could recontaminate fresh mayonnaise. Discard old or spoiled foods.
Handle Leftovers Properly
Only keep leftovers containing mayonnaise for 3-4 days. Discard any leftovers that sit out for more than 2 hours. Store leftovers in sealed, shallow containers to allow rapid chilling.
Recap of Expiration Timeline
Here is a summary of how long mayonnaise should last under different conditions:
- Unopened mayonnaise: About 3-4 months past the printed expiration date.
- After opening: 2-3 months.
- Leftover mayo-based dishes: 3-4 days in the fridge.
- Mayonnaise left out: Discard after 2 hours at room temperature.
The Bottom Line
With proper storage and handling, mayonnaise can stay fresh and safe for months past its printed expiration date. However, once opened it has a shorter shelf life of just 2-3 months. Always refrigerate opened mayonnaise and watch for signs of spoilage like smell, color, and texture changes. Discard immediately if any mold, water separation, or foul odors develop. Following basic food safety practices allows you to keep mayonnaise on hand for sandwich spreads, dips, dressings, and more without worrying about foodborne illness.
