Why is it so difficult to hard boil an egg? I get a green ring around the yolk, or I peel the egg and take half the white with it.
–Susan in Teaneck
Eggs are not easy. Those innocent looking little ovoids are seething with complexes.
Peeling is tricky when the egg’s very fresh because it has a high acid content. Eggs closer to their expiration dates contain less acid, so they’re less likely to have those sticky shells. How you cook and cool them down makes a difference, too. Cook them in salted water to help firm the white. Once they’re done, cool them fast in cold running water.
Green rings come from the blending of iron and sulfur. That happens with overcooking, cooking at too high heat, or not cooling the eggs quickly enough.
Hard-cook eggs this way: Put cold eggs in a saucepan, in a single layer. Cover in cold water by about 1-1/2 inches. Add 1 teaspoon salt for every 4 eggs. Bring the water to a boil over medium high heat and then immediately lower heat so that the water bubbles very gently. Cook 3 minutes. Cover the pot, remove it from heat and let stand 15 minutes. Cool the eggs under cold running water. When they’re cold, peel or refrigerate up to 4 days.