Egg Float Test – Every Thing You Need to Know!

Eggs usually last a lot longer than people realize. An unrefrigerated egg is usually able to last for at most two weeks whereas to preserve them longer you can always refrigerate them which makes them last for a lot more than two months. But whenever you’re in doubt that your eggs might be rotten and are no longer good to use, you can always do the egg float test and find out for sure as eating a bad egg can definitely make you sick and can cause food poisoning. egg Incubator Review

We’re sure you’ve heard of this test at least once in your life. But have you ever wondered what it is exactly? Or have you ever tried it by yourself as a home experiment? Whether if it’s just a myth or does it actually work? Well then if you’re wondering all of this, then you’re definitely in the right place because today we’re going to explain what this test really is and provide you with the answers to all of your questions.

Egg Float Test

The egg float test is basically just a simple test that is performed to check or ensure the freshness of an egg. With this test, one can check whether the eggs that they just brought from the grocery store are as fresh as they say, or are they fooling you. This simple test is all you need to be sure of yourself. Let’s get to it then.


The eggs we buy often come with an expiration date and most of the time good, edible eggs go to waste because we rely on the expiration date and throw them away. The egg float test is a simple five-minute test, which you can easily perform at your own home without causing any hazards or much less burning down the entire house. This test is basically an old-fashioned way to determine how old an egg is. The requirements to perform this test are pretty simple and things you’ll definitely find in your home. So let’s get to it.

Following are the apparatus which are a must for the egg float test:

  • A bowl or glass
  • Water
  • Egg/s


To perform this experiment accurately, we need to make sure that the apparatus is set properly. The setup is usually the most important step of performing an experiment, keeping in mind the limitations and things that may affect the results.

Start by filling a bowl with cold water. The water in the bowl or glass should be enough for the egg to be properly submerged in it plus a few inched more so it doesn’t easily come out of the water. The bowl should be placed on a steady and smooth surface so that the water level is even and doesn’t have any sort of movement in it.


Following are the steps which should be performed to get precise and accurate results:

  1. The first and most important step is to place the bowl of water on a smooth surface.
  2. Submerge the egg into the water gently so that it doesn’t break.
  3. Wait for the egg to be steady.
  4. Repeat these steps with different eggs and whether they’re good to eat or not.

Important Points:

While performing this experiment, a few points should be kept in mind, that they should be followed and certain specifics, which should be taken care of. They are as follows:

  1. It should be made sure that the water placed in the bowl should not be too warm either too cold. It should be at room temperature or a little cold otherwise it could affect the results of the experiment.
  2. The bowl or glass should be placed on a smooth and steady surface at all times so that there are no disruptions in the water and the egg comes to a steady position. Moving or rough surfaces can cause the water level to be uneven and have disruptions in it which as a matter of fact can lead to inaccurate results and can lead to you eating some bad, old eggs. Well, we don’t want that now do we?
  3. The most important point to be taken into consideration is the fact that the eggs should be uncracked. Now some of you may think that this was an obvious fact but you never know someone may crack them open into the bowl of water.
  4. In addition to this, the eggs should be kept in the water one at a time and not all together. This can make the eggs collide causing them to move and not provide accurate results.


After performing the above steps and following the specifics we move towards the analysis and results of our experiment. We will be describing three alternate results, which you can get from this experiment for each type of egg so you can identify whether the experimented egg is fresh, a bit old or not be eaten. For each type of egg, it has a different behavior regarding its position inside the water. That is what we will be discussing here.

  • Fresh Egg:

When a fresh egg is submerged into the bowl of water it attains a position. After a few seconds when it becomes steady, the fresh egg doesn’t float or move, rather it rests at the bottom of the bowl on its side without floating or coming up to the level of the water. This happens because of the fact that a fresh egg has a higher density than that of water, which means that it is heavier than water which causes it to sink in the water.

  • Not That Fresh:

An egg that is not that fresh but still good enough to eat, when submerged into water comes to a steady position. Unlike the fresh egg where the egg lays on its side, this type of egg stands straight up with its large end facing up while still submerged in the water. This usually happens when eggs reach their expiration date and we rely on it, throwing away the eggs which are still good enough to eat resulting in wastage of money.

  • Bad Egg:

A bad egg is the one that no longer remains submerged and comes to the level of the water and starts to float. Just to ensure whether your results are true and accurate, crack the egg open to observe its appearance and smell it.

A rotten egg usually has a flattened, discolored yolk and a slimy, clouded white. You won’t have the need to even do the sniff test as a rotten egg has a very strong and bad odor that you could smell right away.

The smell is from the gas known as hydrogen sulfide (H2S) which is in nature much heavier than air, flammable and toxic to humans which is why rotten eggs should be discarded right away. That is the egg you should definitely throw away unless you want to get sick of course or maybe prank a friend.

Final Results:

Determine the type of your egg with its behavior when placed in the water. That way you’ll know whether your expiration date tells the truth or are you wasting your money in buying a new carton of eggs for yourself. Find out your results by placing the eggs in the water one at a time keeping in view the above-mentioned procedure and specifics so that you attain accurate and precise results.

Is the Egg Test Accurate?

According to many results and reviews, this test has withstood all other tests and is proven to be quite accurate. In spite of the fact that it’s a very simple test, it is one of the most reliable and easiest one to check the freshness of an egg.

It although seems like an old folk’s tale or much less, a myth but this truly does work. People who perform this test and have a lot of practice can easily tell how fresh the egg is without any chances of wrong results.

Why Do Fresh Eggs Sink?

Fresh eggs sink due to the factor of density. A fresh egg sinks to the bottom because of the fact that the egg yolk, egg whites, and other gases present inside the egg make up most of the mass due to which the density of the egg increases leading to the egg having a density much more than that of water.

There is a very small or no air sack inside a fresh egg as it has not been exposed into the atmosphere for a very long time which means that no or very less amount of air entered the shell.

Density is defined as the mass per unit volume and in simpler words, a fresh egg is heavier as compared to the water in which it is placed.

Why Do Bad Eggs Float?

When an egg starts to rot or starts its decomposition process it releases gases. As the egg rots its mass starts to convert itself into gases. However, a change in the state of matter from liquid to gases doesn’t affect the mass as well as density. Then what makes the egg float?

The shell of an egg is porous, which means that has tiny holes enough for gases to escape. As the liquid inside the eggshell changes to gas, some of it escapes through the shell and into the atmosphere. Gases, although they are light, affect the density of the egg. When gases are lost through the shell, it leads to a loss in the density which leads to the density of the egg being less than that of the water, making the egg lighter as compared to the water, causing the egg to float on the surface of the water.

In addition to this another theory also suggests that as the gases inside the egg can leave the shell from its pores, air from the atmosphere can also enter inside the shell creating air pockets and drying out the inside of the egg.

Why Do Eggs Rot?

The rotting of eggs is due to many reasons. The majority of the time it is due to eggshells being cracked, not washed properly and not storing them in a favorable environment.

During the decomposition process, the egg becomes more alkaline because of the fact that eggs contain carbon dioxide in the form of carbonic acid. Due to the reason that the egg becomes alkaline, it enables the hydrogen and sulfur present in the egg to be able to react better which leads to the formation of hydrogen sulfide gas. Eggs should be kept in cooler temperatures as this process happens more quickly in room temperatures.

In spite of the fact that the eggshell has pores so small that it doesn’t let bacteria enter the egg but the small number of bacteria already present inside the eggs is more likely to grow in a warm environment which is why eggs are most likely kept in refrigerators.

Do Brown Eggs Affect the Float Test?

Some of you all may think whether this float test works for brown eggs or any other type or color of the egg. It will not. The results for each type of egg will at all times be the same for rotten of good eggs. There is no difference in the composition of eggs except for their color which is due to the gene of the chicken and does not affect the structure of the egg either the results.


Apart from this floatation test, there are many more alternate ways to test the freshness of an egg.


A method used by professionals in embryology to study the growth of an egg from the inside is known as candling. This method is what requires a lot of skill and is not easy as well as not recommended to be performed by beginners without proper training.

It is a cheap way to study the insides of an egg at particular points. As you can tell by the name, initially this method was done with the help of candles but now due to advancements in technology, it is performed with the help of small, powerful lights.

For this method, dirty eggs are not to be used and should be kept in an incubator which is a device used to keep eggs warm and in the correct humidity when hatching.

Shake Test:

This test is also another easy way to check an egg by holding it up to your ear and shaking it. As a fresh egg contains more of the egg yolk and whites, it has more mass and less empty space that means it will make less sound when shaken. The sloshing sound is usually the one that gives away an old egg and you should probably throw it out.

Whereas a rotten or old egg will make more sounds like the mass inside changes into gas creating a gas pocket and allowing the leftover yolk to move around more. Shaking a rotten egg will produce more sounds than that of a fresh egg.

Sniff Test:

The sniff test is one of the most basic methods to check an egg by cracking it open on a plate.

Once you crack an egg open you can determine by its smell whether it is fresh or not. A rotten egg will have a smell by which you’ll definitely identify it. The smell is caused due to the gas hydrogen sulfide which produces due to the reaction of sulfur and hydrogen present inside the eggshell.

Crack Test:

Cracking the egg open is also another way to know whether it is fresh or not.

A fresh egg will have a vibrant yellowish colored yolk which will sit straight up and the white would be tight rather than cloudy.

A rotten egg comparatively would have a flatter, discolored yolk and its white a lot slimy and clouded. The smell is enough to give it away though.


Surprisingly, eggs can be preserved or kept for a very long time given the fact that they are taken proper care of and kept in favorable temperatures. Eggs can usually last up to eight weeks after they are laid. The bacteria inside them are what usually makes them rot but keeping eggs at a temperature of 4oC or below prevents, or slows down the growth of the bacteria making them last up to weeks perfectly fine to eat.

You can even freeze eggs for up to a year! Shocking isn’t it? For that, all you need to do it beat them lightly. It is advised to store the beaten eggs in ice cube trays and your eggs will remain as good as new.


People across the world have their own traditions and ways of storing eggs and cleaning them.

As per researches and professional testing, it is advised that eggs should be stored at 40-45F.

When in refrigerators you should not place them in the door where the usual space is made as we all admit that we open and close the refrigerator door very frequently and that leads to temperature variation which can affect the preservation of the eggs.

Most of the time when we bring in eggs from the store, we usually arrange them in the egg section in the door of the fridge. Now that is something you shouldn’t be doing. We recommend that you store your eggs in their carton at all times. The reason behind that is that the carton protects the egg from sucking up other fragrances present inside the refrigerator and with that, you can also be sure of the expiration date at all times which guarantees whether your eggs are still fresh or not.

When putting them in a tray or the carton itself, always make sure that the large ends of the eggs should be facing up rather than down. Because of this the yolk inside remains in positions and doesn’t spread out.

If you own hens at your house or at a farm animal hygiene is also very necessary. Usually, the eggs rot due to the fact that the hens are kept in a small pen or that there are a lot of hens stored in a small place which leads to viruses and infections. It is advised to keep your hens in a wide, open space and for their nests to be cleaned and maintained properly and frequently. Because if the hens get infected it can lead to diseases in the eggs, they lay which can transfer into humans as well.

Make sure to check your eggs as a rotten egg can ruin an entire carton of eggs or the ones close to it. You should check and dispose of any egg which is rotten from the fresh batch to help them stay fresh.

Keep your eggs in favorable conditions at all times to preserve them correctly.


In conclusion, the egg float test is most preferably the easiest and quickest way to determine whether the egg is still good to go or to be thrown away. For a healthy life and to avoid eating rotter or bad eggs, always ensure with the methods mentioned above. Eggs should always be kept clean and to be stored in the refrigerator or at a cold temperature at all times to avoid the bacteria present inside from growing rapidly. These different tests allow you to ensure what you eat. We all want to be safe now, don’t we?

According to research made in the USA, many of the eggs which are still good enough to eat are thrown away as people tend to rely on the expiration date more. This causes disruption in the economy, as well as a lot of eggs, go to waste and people have to buy new ones. Therefore, in the final conclusion, be sure of yourself at all times, test your eggs at home and avoid wasting your money.

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