Required materials: eggs, quicklime, alkali, water and sawdust. Production process: Boil the water until the water temperature is cool enough to start, and add alkali. Try to put alkali and eggs together. The amount of alkali is equivalent to putting down an egg, which is about ten cents above the water. The eggs above the water are too big, which means that there is too much alkali, and the eggs come out feel like burners, and vice versa. After putting the amount of alkali, pour in the quicklime. This amount is best to be able to get on the eggshell. Pinch a circle with a slightly thicker wire (just covering the egg to prevent it from being burnt by lime) to catch the egg. Take the eggs out and roll them in sawdust with lime, then put them in a plastic bag and seal them for a few days (it is best to put them in spring, eight days in cold weather and seven days in hot weather, because the temperature is the most suitable and easy to grasp), and then take them out and let the wind blow for a day.