Why do we observe a greenish ring around the yolk of hard-boiled eggs?

Perfect cooking: the foolproof method

There’s a simple technique, approved by everyone who wants perfectly hard-boiled eggs, without any unwanted discoloration.

Always start with cold water.
Place your eggs in a saucepan, cover them with a few centimeters of cold water, and heat gently.

As soon as it boils, turn off the heat.
As soon as the water starts to boil vigorously, turn off the heat. This trick prevents the egg from overheating.

Let it rest.
Cover the saucepan and leave the eggs in the hot water.
• 9 minutes for a soft, creamy yolk,

• 12 minutes for a firm yolk, perfect for a picnic.

An ice bath for perfect results
The ultimate secret: plunge them immediately into very cold water. The thermal shock stops the cooking process and prevents the formation of the dreaded green ring.

Peel them without stress
After five minutes in ice water, the shell comes off easily, especially if you crack it under running water.

Bonus tips for even better eggs

Because we like to go beyond the simple recipe, here are a few tips that really make a difference:

Choose eggs that are a few days old: they peel much more easily than very fresh ones.

Add a pinch of salt or a splash of vinegar to the water: this reduces the risk of cracks during cooking.
Store them properly:
in their shells, up to a week in the refrigerator;
already peeled, 2 to 3 days maximum. What to do with hard-boiled eggs? A few quick ideas.
Their practicality makes them valuable allies in the kitchen. You can:
Chop them to enrich a mixed salad,
prepare homemade deviled eggs,
slice them on avocado toast,
slip them into a sandwich or wrap.
With a few simple adjustments, your hard-boiled eggs will finally retain a bright yolk and a delicious flavor, every time you cook them.

This simple ritual helps you go to the bathroom every morning.