Why is the yolk of my hard-boiled egg turning green?

Does it mean the egg was bad?

No. The green ring is not a sign of spoilage. A bad egg usually has a strong, unpleasant odor when cracked open—very different from the mild sulfur smell you might notice in overcooked eggs.

The takeaway

That greenish tint might not look appealing, but it’s simply a sign your eggs spent a little too long in hot water. With a few small tweaks to your cooking method, you can keep your yolks bright, tender, and perfectly cooked every time.