There’s an easy, smart way to test if your eggs are still fresh without having to rely on carton dates or numbers: do a float test!
How to Test the Freshness of Eggs in Water
The process is really as easy as it sounds: simply fill a bowl or a glass with cold water, then carefully submerge the egg you’d like to test.
- If the egg sinks to the bottom and lies flat, it’s still fresh and safe to eat.
- If it sinks but doesn’t lie flat and remains standing on one end, it’s safe to eat but isn’t quite as fresh.
- If the egg does not sink to the bottom and instead floats on the top, it’s too old to be eaten safely and should be composted or discarded.
Why the Water Float Test Works
This clever test works because as eggs age their shells become more porous, which allows more air to flow through them. The more air flows through the shell, the larger the pocket of air inside the egg (known as the air cell, which is between the membrane and the shell at the bottom end of the egg) becomes.
Eventually, the air cell become so large it causes the egg to float, signifying the egg is no longer fresh.
Other Ways to Check the Freshness of an Egg
While the water test is one of the easiest ways to determine an egg’s freshness, there are a few other methods that work, too.
A sniff test is the oldest, simplest approach. Simply give your eggs a good sniff. If they’re bad, they’ll give off a rotten, sulfurous odor. Sometimes this can be hard to notice when the eggs are in their shell, so feel free to crack the eggs into a bowl and then give them a sniff.
Another approach is to give the eggs a shake. If you hear a sloshing sound, it could mean the yolk is too old and, therefore, watery. A fresh egg won’t make any sound at all when you shake it.