What causes the green ring around the yolk of hard-boiled eggs?

 

Do you love hard-boiled eggs for a picnic, a mixed salad, or a quick breakfast? Yet, one detail intrigues you every time: that greenish ring around the yolk. Is it normal? Is it still safe to eat? And most importantly… can it be avoided? We’re lifting the veil on this culinary phenomenon and giving you all the tips for making hard-boiled eggs that are as beautiful as they are delicious.
Why do your hard-boiled eggs turn green?

You’ve probably noticed this greenish border around the yolk, a bit like an unappealing tint. Rest assured: it’s neither a sign of expiration nor a genetic anomaly. This phenomenon is explained quite simply by… chemistry! When the egg is overcooked, the sulfur in the white reacts with the iron in the yolk, which gives this greenish-gray coloring around the edge of the yolk. Not very appetizing, certainly, but perfectly edible.

 

 

The simple trick to avoid the green circle

Good news: you just need to follow a specific cooking time to get a uniformly colored yolk! Here’s the very easy method:

Place the eggs in a saucepan and cover them generously with cold water (about 2 to 5 cm above the eggs).
Heat over medium heat until boiling.
As soon as the water boils, turn off the heat, cover the pan, and leave the eggs in the hot water.
For a slightly runny yolk: 9 minutes.
For a firm yolk: 11 to 12 minutes.
Immediately plunge them into an ice water bath for 5 minutes to stop the cooking and make peeling easier.
And there you have it, eggs with no green streaks and the perfect texture!

Little tips for trouble-free cooking
Cracked eggs? Add a pinch of salt or a tablespoon of white vinegar to the cooking water to reduce the risk of cracking.
Difficult to peel? Crack the shell and peel the eggs under running cold water. This makes it easier to remove the shell without damaging the white.
Storage: Unpeeled hard-boiled eggs can be kept for up to a week in the refrigerator. Once peeled, consume them within 2 to 3 days.
Why are eggs good for your health?

In addition to being simple to prepare and highly versatile, eggs are a true ally for your balanced diet. Rich in protein, they contribute to muscle recovery and promote a feeling of satiety. The yolk, meanwhile, contains choline, a nutrient essential for memory and concentration. And the icing on the cake: an average egg contains around 70 kcal!

Which proves that for perfectly boiled eggs, good timing and a few well-chosen tips make all the difference.