Question: Why do my hard-cooked egg yolks turn green?

Answer:

If your eggs bring to mind the Dr. Suess story, fear not. For one thing, "green" eggs are not in any way unsafe, nor do they taste off—but they are unsightly. The discoloration around the yolk is due to a reaction between sulfur in the egg white and iron in the yolk. It occurs when eggs have been cooked for too long or at too high a temperature. The method of cooking eggs—in hot, not boiling, water, then cooling immediately—minimizes this.

What I do, is place my eggs in a non-aluminum pan, cover with water, bring the water and eggs to a boil, turn off the stove, put a lid on the pan and let the eggs sit in the hot water for no more than 30 minutes. Immediately, drain the hot water off the eggs and rinse with cold water. Let the eggs sit in the cold water for several minutes to cool the eggs completely.

When you peel the eggs, Viola, there will be no green, just the nice yellow yolk!

Also, the fresher the egg, the harder to peel. So, if you are hard boiling eggs for Easter or a potato salad, be sure and purchase your eggs a week in advance so they will peel easily when hard boiled.