Surprising Truth: How Long Can Mayo Sit Out?

How long can mayo sit out? Do you ever wonder about mayonnaise’s shelf life after it’s been opened? With so many varieties, brands, and expiration dates listed on various containers, it can be hard to tell how long mayo can safely remain out of the fridge.

In this blog post, we’ll break down everything you need to know about storing mayonnaise when preparing meals. We’ve got you covered from proper conditions for keeping it fresh and delicious to safety tips designed to keep your food free from contamination or spoilage. So let’s get started and answer the question: how long can mayo sit out?

A brief answer:

Do not leave opened mayonnaise out of refrigeration for more than two hours. This is especially important in hot and humid environments. Leaving it out any longer could result in food-borne illnesses.

What is Mayonnaise?

First and foremost, let’s quickly review what mayonnaise is. It is a thick condiment made of eggs, oil, vinegar or lemon juice, and seasonings. Although it can be purchased in jars or cans, most people prefer to make their own homemade versions. This recipe usually involves mixing the ingredients together until they form a smooth, creamy mixture.

When it comes to mayonnaise, you want to make sure that it is stored correctly and used within a safe amount of time. It is important to note that, unlike other condiments, mayo cannot sit out at room temperature indefinitely due to the risk of bacteria contamination over time.

Ingredients in store-bought mayonnaise

When purchasing store-bought mayonnaise, it is important to note that the ingredients used vary among brands. Most commercial brands contain eggs, vegetable oil, vinegar or lemon juice and various additives such as salt, sugar, spices or preservatives. Some also include egg whites and/or yolks, which can increase the risk of contamination.

Read More: How Long Does Vacuum Sealed Salmon Last in The Fridge

Ingredients in home-made mayonnaise

mayonnaise sauce

On the other hand, homemade mayonnaise is usually made from raw eggs which increases the risk of foodborne illness. This type of mayonnaise also tends to have more oil than commercial mayonnaise, which makes it more likely to go bad. Therefore, it must be stored and handled differently in order to keep it safe for consumption.

How Long Can Mayo Sit Out?

The USDA recommends that mayo should not be left out at room temperature for more than two hours. This is because mayonnaise is made with eggs, which are a high-risk food for foodborne illness. When mayo is left out at room temperature, bacteria can grow rapidly, leading to spoilage and potentially making people sick.

If you’re not sure how long the mayo has been sitting out, it’s best to err on the side of caution and throw it out. It’s not worth the risk of food poisoning, which can cause symptoms such as nausea, vomiting, diarrhea, and fever.

|Read: How Long Does Better than Bouillon Last After Opening?!

However, if the mayo has been stored in the refrigerator and has not been left out at room temperature for more than two hours, it should be safe to consume. Mayo can last up to two months in the refrigerator, but it’s important to check the expiration date on the jar.

Factors That Affect the Shelf Life of Mayonnaise

The shelf life of mayonnaise depends on various factors, including the type of mayo, the storage conditions, and the ingredients used to make it. Here are some of the most important factors to consider:

1. Type of Mayonnaise: There are different types of mayonnaise, including homemade and store-bought. Homemade mayo typically has a shorter shelf life than store-bought mayo because it does not contain preservatives.

2. Storage Conditions: Mayo should be stored in a cool and dry place, away from direct sunlight and heat. Exposure to heat and light can cause the oil in the mayo to break down, leading to spoilage.

3. Ingredients: The ingredients used to make the mayo can also affect its shelf life. For instance, if the mayo contains raw eggs, it will spoil faster than if it contains pasteurized eggs.

How to Tell if Your Mayo Has Gone Bad

If your mayo smells or tastes bad, chances are it has gone bad and should be discarded. Other signs of spoilage include:

  • Change in color or texture
  • Any signs of mold
  • Curdling
  • Separation of the oil from the rest of the mayo

If you can’t tell visual inspection, you can try to taste a tiny amount. If it tastes off or has a strong, sour smell, discard it.

Read More: How Long Are Crumbl Cookies Good For

What Happens when You Consume Bad Mayonneise

Tempting though it may be, eating outdated or contaminated mayonnaise could have serious consequences. Its ingredients, particularly egg yolks, can cause food poisoning if consumed after their expiry date — leading to illnesses ranging from mild discomfort to hospitalization.

Symptoms of food poisoning include nausea, vomiting, diarrhea, and fever. If you experience any of these symptoms after consuming mayonnaise that has gone bad, it’s important to seek medical attention right away.

Tips for storing mayonnaise

mayonnaise in a burger

Here are some tips to follow when it comes to storing your mayonnaise:

  • Make sure that you refrigerate the mayo immediately after opening, as well as any leftovers.
  • Always keep the lid on tightly and store in the back of the refrigerator, away from any other strong-smelling foods.
  • Store the mayo in the back of the refrigerator, where the temperature is the coldest.
  • Check the expiration date of store-bought mayonnaise before opening it and discard if it is past due.
  • Homemade mayo should be stored in an airtight container in the refrigerator and used within 5 days of making it.
  • Store any prepared dishes containing mayonnaise in the refrigerator for no longer than 4 days before consuming.


How long can mayonnaise last in the fridge?

Most store-bought mayonnaise can last up to two months in the refrigerator. However, it’s best to check the expiration date on the jar for the most accurate shelf-life information. Homemade mayonnaise should be used within five days of making it.

Can I freeze mayonnaise?

Mayonnaise cannot be frozen, as it will separate and become watery when thawed. If you need to store the mayo for longer than two months, it’s best to keep it in the refrigerator.

Can I leave mayonnaise out at room temperature?

No, mayonnaise should not be left out at room temperature for more than two hours. Mayonnaise is made with eggs, a high-risk food for foodborne illness. When mayo is left out at room temperature, bacteria can grow rapidly, leading to spoilage and potentially making people sick.

How long may a mayo-filled sandwich be left out?

Leaving a mayo-filled sandwich out for more than two hours is not recommended, as it could become a breeding ground for bacteria. If temperatures are above 90°F, discarding the sandwich after one hour is best.

After that time has passed, throw away any leftover sandwiches and wash your hands thoroughly with soap and warm water.

Can mayonnaise be reused after it has been opened?

Yes, you can reuse store-bought mayonnaise if it hasn’t gone bad or developed an off smell or flavor. Homemade mayonnaise should not be reused as it is more likely to spoil quickly.

It’s important to store mayonnaise properly after opening and follow the expiration date on the label as closely as possible. This will help ensure it stays fresh and safe to eat for as long as possible.

How long can homemade mayonnaise be stored without refrigeration?

Homemade mayonnaise should not be left out at room temperature and should always be stored in the refrigerator. It’s best to use it within 5 days of making it, as this will help ensure it stays fresh and safe to eat.

Bonus: The secret ingredient to make homemade mayo last for months

Mayonnaise is a delicious condiment that is a staple in many households. However, it’s important to know how long it can sit out without spoiling to ensure its safety for consumption. Remember to store mayo in the refrigerator, check the expiration date, and throw it out if it’s been left at room temperature for over two hours. By following these simple tips, you can enjoy your favorite mayo-based dishes without the risk of food poisoning.

Further Reading: