Before you toss that carton from three weeks ago, do yourself a favor: perform the float test. Drop a whole, uncracked egg into a bowl of cold water. If it sinks and lies flat on its side, it’s fresh enough to star in a Michelin-star commercial.
If it stands on its little end like a tiny, cowardly submarine? It’s older but still edible—use it for hard-boiling or baking. But if that egg floats to the top like a bloated corpse? Throw it away. It’s not a miracle; it’s a gas bomb made of rotten sulfur.
Why does this work? Over time, eggs breathe through their shells (yes, they have tiny pores). As they age, they lose moisture and carbon dioxide, and that pocket of air inside gets bigger. A floating egg is basically screaming, “I’ve been here too long!”
