How To Tell If Your Eggs Have Gone Bad

There's really nothing worse than trying to nurse a Sunday morning hangover with an omelet, only to discover you've got a fridge full of expired eggs. This begs the question: are they still safe to eat? Eggs stay fairly fresh well beyond the expiration printed on their cartons, but how can you tell when they've officially gone bad?

Here are five easy tips to keep you from scarfing down something rotten.

The simplest way to test an egg's freshness is to drop it in a glass—or bowl—of cold water and see what happens. If it sinks to the bottom and sits on its side, it's still fresh. If it sinks but sits on its end, it's less-fresh but still edible. If it floats, toss it out, it's officially bad. The reason this works is because an egg's shell is porous, and the liquid inside slowly evaporates over time, leaving a pocket of air large enough to make it buoyant.

In a darkened room, hold a flashlight against the shell to see what's going on inside. In a fresh egg, you should see only a sliver of air at the top and a light yolk in the middle. If there's a slightly larger pocket of air and a darker yolk, the egg's still fine but you should use it soon. If there's a gaping area of air and some coagulated yolk, toss it.

Generally, if you can hear the liquid swishing around inside the egg when you shake it, it's gone bad. The sound usually indicates a watery old yolk. Similarly, if you're trying to determine whether it's hard-boiled or not, spin it on its side on a table and try to stop it by quickly tapping it with your finger. If it continues to rotate, it's uncooked.

Once an egg's cracked there's an easy way to judge how fresh it is before you start cooking. A fresh egg will have a white that's taut and raised around the yolk, while a less-fresh (though still edible) egg will have a white that's more spread out.

Though only the most well-trained nose will be able to detect if an egg's turned while it's still in the shell, a rotten one will make itself known to anyone in its vicinity once it's cracked. The pungent sulphuric smell means they're seriously rotten.

Joe McGauley is a senior editor at Supercompressor and doesn't even like eggs that much.

Want more of the Culture you actually care about delivered straight to your inbox? Click here to sign up for our daily email.