Ingredients :

• The eggs — A detail few people know: an egg that is 8 to 10 days old peels much better than an ultra-fresh egg. The inner membrane sticks less to the shell with age. You won’t have this problem with supermarket eggs. And take them out of the fridge 10 minutes before — a cold egg plunged into a hot pot tends to crack.
• Starting with cold water — It sounds like a harmless habit. It isn’t. Starting with cold water allows the egg to heat up gradually with the liquid, which reduces the risk of cracking and results in more even cooking of the white.
• Ice cubes (or very cold water) — The step everyone skips because it seems optional. It’s not. Without this thermal shock, the egg continues to cook in its own heat for several minutes after you’ve turned off the stove — and that’s exactly the timeframe when sulfur and iron combine to form the greenish ring.