The float test is a simple way to determine how old an egg is. 

When you have extra eggs and they start to pile up, unless you mark or otherwise keep track of how old the eggs are, it's easy to lose track of which are the oldest. 

Because of course it's impossible to tell how old an egg is just by looking at it (or is it?)

But there's an easy way to tell just how old an egg is. And I'll show you!

The Egg Float Test for Freshness

Eggs will keep a lot longer than you probably realize.  So don't automatically throw out eggs that you feel like have been languishing in the fridge forever.

But, realize that the older the egg, the more chance that bacteria has had the opportunity to seep into the egg through the pores in the eggshell and multiply.

So when in doubt, just do the Egg Float Test for freshness.  It's simple. 

Just fill a clear glass with warm water (cold water can cause any bacteria on the shell to be drawn into the egg) and gently drop the egg in. 

Float Test for Freshness

  • Freshly laid eggs will lie flat on the bottom of the glass.
  • After 1 to 2 weeks, one end of the egg will begin rise off the bottom of the glass.
  • After 2 months or so, the egg will likely be standing straight up with just the pointy end touching the bottom of the glass.
  • Eggs older than 3 months will likely float and should be tossed out.

Very Fresh Egg

The egg in the photo above was just laid. As you can see, it's sitting flat on the bottom of the glass. It was laid this morning, so no air has had time to seep in through the pores in the shell.

Not Quite as Fresh Egg

The egg in the photo above is a couple of weeks old. You can see that the blunt end of the egg has started to rise up off the bottom of the glass a bit.

As the egg ages and air seeps through the pores in the eggshell, the air sac inside the egg enlarges as the inside of the egg start to dry out. That causes one end of the egg to rise.

By the time it's two to three weeks old, an egg will begin to lift up off the bottom of the glass.  

The egg is also losing valuable nutrients as it ages, and the white will start to thin out and spread out more in the pan when you cook the egg.

Old Egg

The egg in the photo above is a couple of months old. 

By the time the egg is a month or two old, it will be visibly angled in the glass, but still perfectly good to eat. 

And by three months the egg will mostly likely be standing straight up, with the pointy end of the egg still touching the bottom of the glass.

As long as one end of the egg is still touching the bottom of the glass, the egg is still most likely fine to eat; it's just old. While it won't taste as fresh as an egg that's not quite as old, it will peel far better if you hard-boil it. 

Fresh eggs are notoriously hard to peel.


Floating eggs are very old.  Likely months and months. So much air has entered the egg, the egg actually floats off the bottom of the glass and bobs in the water.  This isn't necessarily a sign that the egg is bad, but it can be an indication. 

At the very least, the egg is OLD. Really old.

As an egg ages, the "bloom" on the surface of the shell gradually degrades and isn't effective any longer at preventing air and bacteria from getting into the egg. 

So the older the egg, the more chance bacteria has gotten inside. It's good practice to toss floaters. No use taking a chance.

Some people dispute that and say that a floating egg is still okay to eat, but at the very least, by the time an egg starts to float it is extremely old and so much air (and possibly bad bacteria like Salmonella) has passed through the shell that the egg now floats. 

And who wants to eat an old egg? 

And why chance it, especially when you likely have plenty of fresh eggs at your disposal? Personally, I would toss any egg that floats.

The one downside to the float test is that once you've submerged the egg, the water will wash off the "bloom" which is the natural coating that keeps an egg fresh

So even if it wasn't previously, that egg will need to be refrigerated and won't stay as fresh is it might have with the bloom still intact.

How to Tell if an Egg is Fresh Without Floating It 

If you want to keep the bloom intact, shake the egg. If you hear sloshing inside, it has likely gone bad and shouldn't be eaten. At the very least, it's old.

And of course if you crack an egg and it smells bad...really bad....or is discolored and cloudy, then it's  obviously no good to eat and needs to be tossed.

Do The Float Test

So next time you discover a broody hen's secrets cache, or aren't able to keep up with the egg supply in your refrigerator, don't throw the eggs away, just pop them into a glass of water before using them.

Most likely they are perfectly good to use.

Remember though, that dunking the eggs will remove the natural "bloom" on the egg that keeps them fresh, so once you've done the Float Test on an egg you should use it right away or refrigerate it.

How to Tell if an Egg has Gone Bad

Just because an egg is old doesn't automatically mean it's not still okay to egg, and conversely, a fresh egg can be contaminated with bacteria.  The Float Test merely indicates how old the egg is.

So it's also important to crack an "iffy" egg into a small bowl - not right into your pan with other eggs or a bowl of batter! Then take a good look at it.

Signs of a Bad Egg include:

  • pink, greenish or iridescent egg white could be bacteria
  • black or green spots inside the egg could be fungus
  • stinky smell 

If you're unsure whether an egg is still good to eat, toss it. Don't take a chance.

Note: reddish or brown spots or streaks aren't a sign that the egg has gone bad. They're likely just blood spots that are completely normal and even edible.

©2012 by Fresh Eggs Daily, Inc. and updated in 2024 for Coop to Kitchen. All rights reserved.