The eggs will not come out during cooking, if the water becomes salted, and the shells will not break, if you add vinegar to the water. Eggs with a cracked shell can be cooked wrapped in a moistened piece of parchment. Cooking eggs should be removed from the refrigerator beforehand or kept under a stream of warm water, to keep them warm. To make them easier to peel off, the boiled egg is cooled down in cold water.