Yes, there is in fact a wrong way to hard-boil eggs. And the wrong way results in rubbery whites and yolks with that signature grey/brown coloring on the outside. Follow these simple steps to a perfectly cooked egg every time!
1. Place eggs in saucepan in a single layer.
2. Fill pan with cold water, covering eggs by 1 inch.
3. Place over medium-high heat. Cover; bring to a boil. When you see the water just starting to get tiny bubbles from the heat, add a spoonful of salt and place lid back on.
4. As soon as the eggs come to a rolling boil, turn off heat; let stand, covered (don’t even think about peeking in there or you’ll lose all of the heat), 12 minutes.
5. Transfer eggs to bowl of ice water.
Let stand for about 5 minutes, then remove. If you’re having trouble getting the shells off nicely, know that the freshness of your eggs impacts that. The fresher the egg, the harder it is for the shell to come off.