How to tell if eggs are fresh is easier than most people think: drop the egg gently into a tall glass of cold water. If it sinks and lies flat on the bottom, it is very fresh. If it stands upright or tilts, it is a few days old but still fine to eat. If it floats to the surface, throw it out — do not taste it, just discard it.
This is called the egg float test, and it works because an eggshell is slightly porous. Over time, air seeps in and moisture seeps out, making the egg more buoyant. Below is exactly what each result means, how to do the test correctly, and how to confirm with a quick crack-and-sniff check.
What Do the Float Test Results Actually Mean?
A fresh egg has a tiny air cell and sinks flat. As the egg ages, the air cell grows larger, so the egg tilts upward and eventually floats. Floating means enough air has entered — and enough moisture has left — that the egg is past its safe window, even if the printed date looks fine.
The middle result surprises people most: an egg that stands on end is older but usually perfectly good for cooking, especially in baked dishes. Age alone is not spoilage. That said, the float test is a screening tool, not a guarantee — always confirm with your nose before cooking, and when in doubt, throw it out.
How Do You Do the Egg Float Test Correctly?
The test only takes a minute, but a few details make it reliable:
- Use a tall glass or bowl of cold water. It needs to be deep enough for the egg to float freely without touching the bottom or sides.
- Lower the egg in gently. Dropping it can crack the shell and let water in, which ruins the test.
- Watch what it does immediately. Sinks flat = very fresh. Sinks but stands tilted = older, still good. Rises and floats = discard.
- Test eggs one at a time if you are checking several, so a floating egg does not contaminate the water for the others.
- Dry and refrigerate the keepers right away. Do not leave tested eggs sitting on the counter — get them back in the fridge promptly.
How Do You Confirm Freshness with the Crack-and-Sniff Check?
The float test tells you about age; your nose tells you about safety. Crack the egg into a separate small bowl — never directly into your batter or pan — and look and smell. A fresh egg has a firm, rounded yolk, thick egg white that holds its shape, and essentially no smell.
A bad egg announces itself: a sulfur or rotten smell, a watery white that spreads flat, or any pink, green, or iridescent tint means it goes straight in the bin. This two-step approach — float first, sniff second — is the most reliable home method there is, and it beats trusting the carton date alone. It pairs well with other egg know-how like how to peel boiled eggs with a shake and separating yolks with a plastic bottle.
Do Expiry Dates Matter More Than the Float Test?
Not really — printed dates are conservative estimates, and eggs often stay good well beyond them if refrigerated properly. The date tells you when the store should sell them; the float test tells you the actual condition of the egg in front of you.
Storage matters more than the date on the box. Keep eggs in their carton in the coldest part of the fridge (not the door), and they can stay fresh for three to five weeks past purchase. Good storage habits extend to everything in your fridge — see how to keep vegetables fresh longer in the fridge and these baking soda hacks every kitchen needs for keeping the whole fridge fresher.
Frequently Asked Questions
Can I eat eggs that stand upright in water?
Yes, generally. An upright egg is older but usually still safe — it is ideal for hard-boiling, since slightly older eggs peel more easily. Just do the crack-and-sniff check first, and use them soon rather than storing them another week.
What if an egg floats but smells fine?
Discard it anyway. A floating egg has lost significant moisture and taken in a lot of air, which means bacteria have had more opportunity to enter through the shell. The smell test cannot catch everything, so floating is a hard no.
How long do eggs actually last in the fridge?
Properly refrigerated eggs stay good for about three to five weeks from the purchase date, often beyond the printed sell-by date. Keep them in their original carton on a middle shelf — the fridge door is the warmest spot and shortens their life.
Does the float test work on all types of eggs?
Yes, the physics is the same for white, brown, free-range, and organic chicken eggs. It also works for duck and quail eggs, though their smaller size means you should use a narrower glass so you can read the result clearly.