How Long Can Mayo Sit Out? Does It Need To Be Refrigerated?

image of mayonnaise go bad if not refrigerated

We’ve all made that mistake before; you think you’ve cleared away after cooking, but you forgot one last thing: the mayo. Now to be safe, you need to ask yourself: how long can mayo sit out?

Short Answer:

Mayo should only be left out for a maximum of two hours. If it is sealed, it can be stored out of the fridge.

Since mayo is made of eggs, it can be very risky to eat if it has been left out.

In this article, we will find out how long you can leave mayo out and go into the best way to store your mayonnaise to keep it fresh and safe to eat.

Let’s get into it.

What is Mayo?

Mayonnaise is a condiment made of an emulsion of egg yolk and oil.(*) It is thick and creamy in texture and pale yellow in color.

This is a classic sauce that you can easily make at home with a few simple ingredients.

Vegan mayonnaise is a condiment that closely mimics mayonnaise without using any eggs.

Keep in mind that ingredients will look different on the labels of shop-bought mayo. This is because they contain preservatives and other additives to make them last longer.

Mayo is made up of a few simple ingredients:

1. Egg Yolk

Only the yolks are used for making mayonnaise as it has the ability to emulsify with the oil. They form the base of the mayo.

The color of the egg yolks will affect the final color of the mayo.

2. Oil

Although egg yolks are the base of mayonnaise, the oil makes up the bulk of the final product.

Usually, around one cup of oil is used per egg yolk.

The best oil to use for mayo is a neutral flavor like safflower or light olive oil. The oil is the reason that you can use raw egg yolks to make mayo safely. 

3. Vinegar or Lemon Juice

The zing and tang of a good mayo are down to vinegar or lemon juice.

The acid helps preserve the mayo, but it also loosens up the texture and adds essential flavor to the neutral emulsion.

Without the acid, mayo would taste more strongly of the egg.

4. Seasonings

Salt, pepper, and other seasonings are added to bring out the flavor and make the mayo very moreish.

How Long Can Mayo Sit Out At Room Temp?

Mayo should be left out of the fridge for no longer than 2 hours.

This is because the mayo will reach a temperature that is ideal for bacteria growth, which will make your mayo go bad.

If you have left the mayo out by accident, you may not be able to remember when exactly you left it out. This is why it is essential to be able to identify if your mayo is fresh.

Fresh mayo will be:

1. Neutral Smell

When you open it, you will smell a faint vinegary smell, but other than that, the smell will be very neutral.

2. Pale Yellow to White Color

The color of mayo changes from brand to brand, but it usually ranges between a pale yellow and almost white.

The yellow shade comes from the deep color of the yolks.

3. Smooth Texture

The texture should be one smooth mix with no separating. 

The texture will change slightly depending on the brand, but it should be thick and easy to spoon out of the tub.

How To Tell If Your Mayo Has Gone Bad

So now that you know what fresh mayo looks like, what if it has gone bad?

Eating bad eggs can make you sick, so you need to be careful not to eat bad mayo.

Bad mayo will be:

1. Rancid Smell

The first thing you will notice is a bad smell.

It will smell powerful and slightly eggy when you open the tub. This is a clear sign that it needs to be discarded.

2. Mold May Be Present

You will notice blue or black patches appearing around the edges of the tub and spreading across the surface of the mayo. 

This is likely to happen if mayo is left out for long periods.

3. Split Texture

Instead of being smooth, the mixture will go watery and split.

You will notice a watery deposit forming on the surface with little pieces of thicker mayo floating in it.

4. Change In Color

As we mentioned, your mayo should be pale in color.

If it begins to darken, then it is a clear sign that it is not safe to the east.

Does Mayonnaise Need To Be Refrigerated?

The best way to store mayo is in the fridge.

Keeping it in the fridge will help maintain a safe temperature within the mayo that will not allow bacteria to grow.

We recommend keeping your mayo in the same container and sealing it well after every use to keep it fresh.

If your mayo is unopened, you can store it in a dark, cool cupboard or pantry.

Mayo will last for up to three months in the fridge.



So, what do you need to know if you have left your mayo?

  • How long can you leave mayonnaise out? Mayo should not be sit out for more than 2 hours.
  • Does mayo need to be refrigerated? It is best to store mayo in the fridge.
  • How long does mayonnaise last in the fridge? Mayo lasts up to three months in the fridge.

We hope this has saved you from accidentally eating some bad mayo and urged you not to leave it out again.

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