Why would eggs turn black while cooking?

Eggs turning black while cooking is a bit of a mystery, and there's no single, definitive answer. Here's a breakdown of potential causes and what you can do:

1. Overcooking: This is the most common culprit. When eggs are cooked too long or at too high a temperature, the proteins within them start to break down and bind together, creating a tough, rubbery texture. In extreme cases, this can lead to a darker, almost black color.

2. Iron: Eggshells contain iron, which can react with the sulfur in the egg white during cooking. This reaction can lead to a greenish-gray or even black ring around the yolk. This is more common with older eggs, as the shell membrane weakens with age.

3. High Heat: Cooking eggs at extremely high heat can cause them to brown too quickly and unevenly, potentially turning some areas black.

4. Contaminated Water: While less common, using contaminated water to boil eggs can contribute to a discoloration.

5. Other Minerals: The water you use to boil eggs might contain other minerals that can interact with the egg proteins and cause discoloration.

What to do:

* Cook eggs gently: Don't overcook them! Aim for a soft-boiled or medium-boiled texture.

* Lower the heat: If you're scrambling or frying eggs, use medium heat.

* Use fresh eggs: Fresh eggs are less likely to have the iron-sulfur reaction.

* Avoid contaminated water: Use clean water to boil your eggs.

* Check for discoloration: If you see a black ring around the yolk, it's not necessarily harmful, but it might indicate the egg was cooked at too high a temperature or was not fresh.

Important note: If the egg white has a strong ammonia smell or the yolk is green, discard the egg. This could indicate spoilage.

Let me know if you have any other questions about eggs!