Spin the egg on a flat surface; a fully cooked egg spins smoothly and steadily
Remove one egg and peel a small section to check the yolk
Cut the egg in half; the yolk should be set to your desired firmness
Shake the egg gently; a fully cooked egg feels solid with no sloshing
Use a timer based on your preferred doneness
For hard-boiled eggs, cook until the yolk is fully firm and the center is no longer runny
For soft-boiled eggs, cook until the white is set and the yolk is still slightly runny
After cooking, place eggs in cold water to stop the cooking process
If the shell peels easily and the white is fully set, the egg is done