Eggs are usually boiled for 5-10 minutes. Wash the eggs before boiling, otherwise they will be dirty. Put into the water and cook until the water boils, then cook for 5 minutes, the egg white is mostly cooked, but the yolk is not yet cooked; cook for 7 minutes, the egg white is ripe, the yolk is partially ripe. At this point it is what we often call a sugar seeped egg; boil the whites and yolks for 10 minutes. Soak the hard-boiled eggs in cold water and remove. At this time, the flavor is just right. If boiled for too long, the nutrients of the egg will be destroyed and the flavor will become old.