If your hard-boiled eggs often develop a green ring around the yolk, don’t worry — it’s completely harmless.

The discoloration is caused by a chemical reaction between the iron in the yolk and the sulfur in the white,

which happens when eggs are overcooked or left in hot water too long. The result is iron sulfide — safe to eat but not very appetizing.

Here’s how to get perfect, golden yolks every time:

1. Start cold.
Place eggs in a pot without crowding and cover with cold water, about 3–5 cm above the eggs.

2. Heat gently.
Bring the water to a gentle boil over medium heat. Once boiling, turn off the heat immediately.

3. Let them sit.
Cover the pan and let the eggs stand in the hot water for 9–12 minutes — shorter for softer yolks, longer for firmer ones.

4. Cool fast.
Transfer the eggs to ice water right away. This halts cooking, prevents the green ring, and makes peeling easier.

Bonus tips: Use slightly older eggs (5–7 days), add salt or vinegar to prevent cracking, and refrigerate unpeeled eggs for up to a week.

The secret? Perfect timing and rapid cooling — the keys to flawless, bright yellow yolks every time.