How To Tell If Your Eggs Have Gone Bad by abc 🌞 def How To Tell If Your Eggs Have Gone Bad1. Shake it up 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.2. Watch the whites 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.3. Sniff it 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.