Egg Float Test: A Simple Way to Check Egg Freshness

Worse than a flat pancake or a smelly omelette is cooking with a rotten egg. Not only does it smell a bit funny, but you could even risk food poisoning.

How can you tell if eggs are off without cracking the shell? The egg float test is a quick home trick that can help. With just a few seconds and a bowl of water, you can see which eggs to keep or toss. Below, we’ll show you how to do it, why it works, plus storage tips and other easy freshness checks.

How to Do the Egg Float Test

To perform the egg float test, fill a bowl or glass with cold tap water. Gently place each egg into the water one at a time. Then watch:

Egg sinks and lies flat on its side: This egg is very fresh and good to eat.
Egg sinks but stands upright (on one end): This egg is older but usually still fine. Plan to use it soon.
Egg floats to the top: The air pocket inside has grown large – this egg is too old and should be discarded.

The sink-or-float outcome tells you the egg’s approximate age. Fresh eggs sink to the bottom and lie flat, and bad eggs float to the top.

If you’re unsure about an egg that’s sitting somewhere in between, you can always crack it into a bowl and sniff it (we cover that below).

It’s Not an Egg Floating Myth, It’s Science

Eggs float when they get older because of changes inside the shell.

An egg’s shell is slightly porous, so over time it lets moisture escape via evaporation. This moisture is replaced by air and gases produced during decomposition, enlarging the pocket of air (the air cell) at the egg’s broader end.

In other words, older eggs have a bigger air bubble inside, making them lighter. When the air cell is large enough, the egg becomes buoyant and will float. Fresh eggs have only a tiny air pocket, so they remain dense and sink.

Egg Storage Tips to Extend Freshness

Beyond testing, proper storage is key to keeping eggs fresh for weeks. In Australia, we usually refrigerate eggs, which greatly extends their shelf life. Experts say you can keep fresh eggs in the fridge for up to six weeks after purchase. Here are some tips to get the most out of your eggs:

Refrigerate in the carton: Keep eggs in their original carton in the fridge. The carton protects them from breakage, prevents them from picking up fridge odours (remember: eggshells are porous), and helps you see the use-by date.
Keep them cold and steady: Store eggs on a middle shelf (avoid the fridge door where temperatures change). A stable cold temperature means less sweating and less bacterial growth. Don’t leave refrigerated eggs out on the bench for more than 1–2 hours.
Pointy end down: Place eggs with the pointed end facing downward (so the air cell stays at the top). This helps keep the yolk centred and slows spoilage.
Mind the dates: Aussie egg cartons have a best before date (usually about 6 weeks from packing). Use this as a guide, but remember the float test is often more telling.
From supermarket straight to the fridge: Pick up eggs last during grocery shopping so they stay cool. When you get home, pop them straight into the fridge to preserve freshness.

Following these tips will keep your eggs fresher for longer. And these hacks will up your home chef skills in no time.

Other Easy Freshness Checks

Besides the float test, there are a few classic tricks to test eggs:

Sniff test: Fresh eggs have no smell. A rotten egg will give off a strong sulfuric (rotten-egg) odour even before you crack it. If an egg (or its contents) smells bad, throw it out immediately.
Shake test: Gently shake the egg close to your ear. A very fresh egg will make no sound. If you hear liquid sloshing inside, the yolk has thinned (a sign of an older egg). If it sloshes a lot, it’s safer to discard it.
Crack-open test: Crack the egg into a clean bowl and look at it. A fresh egg has a round, plump yolk and thick white that stays close to the yolk. An old egg will have a flat yolk and watery white that spreads out thinly. Also, check for any unusual colour or blood spots. If the white is very runny, the yolk breaks easily, or you spot any cloudiness or off-colour, it’s best not to use it. And of course, if it smells bad after cracking, throw it away.

These simple tests can be done at home without special equipment. Combined with the float test, they help make sure you only cook with eggs that are fresh and safe. Want more tips? Read our complete guide here: How to Tell if Eggs Are Off.

Egg Float Test Wrap-Up

The egg float test is a handy little kitchen hack for busy Aussie families. It’s cheap, easy, and fun (kids can help!), and it’s more reliable than best-before dates alone. Combined with the sniff/shake checks and good storage, it means fewer surprises — and less food waste.

So next time you’re unsure about an egg, just fill a bowl with water and drop it in. A sinking egg is good to go; a floating egg says it’s time to toss and get a fresh one. With these tips, you’ll always know how fresh your eggs are and can enjoy them safely.

Looking for more time-saving egg hacks? These tips will make home cooking a breeze!

Is an egg still good if it stands up in water?

Yes – an egg that stands upright (but doesn’t float) in water is still generally safe to eat. It’s older than a fresh egg, but not necessarily bad. Just be sure to crack it into a separate bowl first and check for any off smells or unusual appearance before using.

What is the egg float test and how does it work?

The egg float test is a simple way to check if your eggs are still fresh. Just place an egg in a glass or bowl of cold water. If it sinks and lies flat, it’s fresh. If it stands upright or floats, it’s best to crack it open and check before using.

Is the egg float test reliable?

Yes, the egg float test is a great at-home indicator of egg freshness. While it’s not foolproof, it gives you a good idea based on how much air has entered the egg over time. For best results, combine it with a visual and smell check after cracking.

Can I still eat eggs that float?

Not always. Floating eggs are usually past their prime and may not be safe to eat. If an egg floats, crack it open in a separate bowl. If it smells off or looks unusual, it’s best to toss it.

How should I store my eggs to keep them fresher for longer?

Store eggs in their original carton in the fridge—not in the door! The carton helps reduce moisture loss and protects eggs from absorbing strong fridge odours.

How long do eggs last in the fridge in Australia?

In Australia, eggs can stay fresh in the fridge for about 4–6 weeks after packing. Always check the best before date on the carton and use the egg float test if you’re unsure.

Do I need to do the egg float test if my eggs are still in date?

Not necessarily—but it’s a handy trick if you're nearing or past the best before date. It’s also helpful if your eggs have been out of the fridge or you’re unsure how long they’ve been stored.

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