What Does It Mean When a Hard-Boiled Egg Floats?

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Have you recently seen the hard-boiled egg from your breakfast floating on the water, which made you wonder if there is something wrong with the egg? Well, many people unaware of the science and logic behind eggs floating on the water often confuse it with their eggs being unsafe to use. 

Multiple reasons could make the egg float on water, whether hard-boiled or raw. However, the most common reason this happens is that the egg you use is older. Some other reasons include the egg’s cracked shell and high salt content in the water, or perhaps because you are using salt water. 

In this guide, I will take you through some primary reasons that make a hard-boiled egg float on the water. I will also explore some signs that can tell you when the egg has gone bad and answer some questions regarding this topic. 

So, to know this and much more about hard-boiled eggs, keep reading until the end of this write-up. 


Why Does a Hard-Boiled Egg Float In Water? 

One of the main reasons why a hard-boiled egg floats in water is because it’s too old. This stands true for both raw and boiled eggs, as the main factor leading to this is the life of the egg. When the egg ages, a cavity called an “air cell” is created inside it.

Note: You can check out this guide to learn more about air cells in eggs.  

Though this cavity is always present in the egg, over time, it increases. As time passes, the air cell expands more due to losing all the moisture from it. If the air cell inside the egg you just boiled for breakfast increases too much, the egg will start floating in the water. 

However, this phenomenon of the floating of hard-boiled or raw eggs in water has nothing to do with any harm in its consumption. Even if the egg you were meant to consume is floating on the water, eating it would be completely safe. 


Other Reasons for the Hard-Boiled Egg Floating In Water 

Though, as I have mentioned above, the primary reason for the egg floating in the water is the expansion of the air cell inside the shell, this is not the only reason why this happens. Here is a list of some other things that could make a hard-boiled or raw egg float in water: 

  • Cracked Egg Shell 

If, while boiling the egg, its shell gets a crack, some part of the egg liquid will leak out and add to the water in which the egg is boiling. Due to this, the overall weight of the egg significantly reduces, making it float in water. 

As far as this reason is concerned, a crack in your egg’s shell doesn’t always make it float in water, as sometimes the crack isn’t large enough to make the liquid flow out of it. However, if the crack is pretty apparent that you can easily see it, the floating is most likely to happen. 

  • Saltwater 

Another thing that could make a hard-boiled egg float in water is the water itself. If you are boiling the egg in water with high salt content, you will most likely see it floating in it.

This happens because the addition of salt in the water causes an increase in the water’s density (Check out this guide to know more about how a higher density of water makes different objects float in it), making it capable of bearing the egg’s weight. Boiling the egg in seawater can also cause the egg to float in water. 


How To Know If Eggs Have Gone Bad? 

One of the major misconceptions most users have regarding floating a hard-boiled egg in water is the egg is going bad. Fortunately, this is not always the case, and at least the floating phenomenon alone isn’t sufficient to spot whether the egg has gone bad or not. 

But don’t worry; this doesn’t mean I will leave you on your own to struggle with deciding if the egg is safe to consume. I have enlisted some significant signs that would tell you whether the egg has gone bad or it is still safe to eat. 

  • Check the “Best By” Date 

The first thing that can help you determine whether an egg is still safe to consume is the “Best by” or “Sell by” date on the carton. This date generally tells you that the eggs are safe to be consumed for around 30 days from their packaging. 

But honestly, you don’t always have to go by the books. You can safely consume the eggs even after the “Best by” date mentioned on the carton. I agree that the eggs’ quality might start deteriorating as time passes, but this still doesn’t take away the fact that they are all safe to be consumed within 21 to 30 days after the “Best by” date has passed. 

So, if you see the egg floating on the water but only a few days have passed since its expiration date, you can safely eat the egg without thinking about any consequences.

  • Perform the “Sniff Test” 

Another thing that can help you clearly differentiate between a safe egg and an egg that has gone bad is the sniff taste. As the name suggests, for this test, you simply have to sniff the egg, and its smell/fragrance will do the rest. 

As far as sniffing is concerned, it’s recommended that raw eggs be sniffed from outside the shell, as this can save you from wasting your money. However, if you have already boiled the egg, remove a small part of its shell and smell the egg from its skin. 

If you are smelling something unpleasant and weird, it’s time to toss the egg in the bin. When performing the sniff test, ensure that some other fragrant object isn’t around. 

  • Use the “Float Test” 

Last up on the list is the float test which multiple users across the globe generally prefer. What you need to do for this test is: 

  1. Fill a large bowl with water.
  2. Ensure the water is clean with no nutrients and salt content. 
  3. Now, put the hard-boiled egg in the water. 
  4. Do not drop the egg into the ball fiercely; this could break its shell, making it float in water. 
  5. Wait a few seconds and see if the egg is floating in the water. 
  6. If the egg rises in the water and you can smell something unpleasant, discard it as it’s not safe to be consumed. 

The floating test can also help you figure out whether an egg under consideration is safe to eat or not. 



Is It Safe to Freeze Hard Boiled Eggs? 

Yes, hard-boiled eggs are entirely safe to be frozen, which won’t make them unfit for consumption. In fact, freezing hard-boiled eggs can save you from the hassle of boiling them every morning as all you need to do is to take them out of the fridge and make them sit around for 20 to 30 minutes till they finally defrost and ta-da! The hard-boiled eggs are all set to be consumed. 

For How Long Do Hard-Boiled Eggs Remain Good? 

Though hard-boiled eggs are much healthier and rich in nutrients than fried or cooked eggs, their lifespan is relatively shorter. It’s because boiling the eggs removes the protective layer inside the shell, exposing them to harmful microorganisms. So, even if you refrigerate or freeze the hard-boiled eggs, they won’t last for as long as raw or cooked eggs. 

Should Hard-Boiled Eggs Be Stored Peeled or Unpeeled? 

As boiling the egg already removes the protective layer from inside the eggs, peeling them will make them much more susceptible to external contaminants, which adds to their risk of going bad. So, if you want your hard-boiled eggs to last long, it’s best to store them peeled. 


Conclusion – What Does It Mean When a Hard-Boiled Egg Floats?

In this guide, I have explored the answer to one of the main questions most egg lovers have, i.e., “What Does It Mean When a Hard Boiled Egg Floats?” I also took you some methods to help you identify whether an egg has gone bad. 

Lastly, I answered some questions regarding hard-boiled eggs. Hopefully, this guide has cleared all your confusion regarding hard-boiled eggs and them going bad, and you won’t get upset about seeing the eggs floating in the water ever again. 



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