Although hard-cooked eggs are frequently referred to incorrectly as hard-boiled; it should be noted that eggs are not boiled if cooked properly. They should be hard-cooked in water just below the boiling point for 12-15 minutes.
If the eggs are taken directly from the refrigerator, start them in cold or lukewarm water. Hot water may crack the shells. When done, chill in cold water to prevent darkening of the yolks and to make shelling easier.
If eggs are allowed to remain in one position while being hard-cooked there is a tendency for the yolks to sink to the bottom. For stuffed eggs it is desirable to have egg yolks in the centre of hard-cooked eggs. To obtain such a result, gently stir the eggs, keeping them in motion for the first 6 or 7 minutes of cooking.