preserved preserved eggs are traditional food for Chinese people. Because of its unique flavor, excellent taste and long shelf life, it is very popular among people. Do the students know? In fact, the process of processing fresh eggs into preserved eggs is a complicated chemical process. The strong alkali (sodium hydroxide and potassium hydroxide) in the ash material permeates into the egg yolk and egg white from outside the eggshell, and reacts with the protein in the egg yolk and egg white, so that protein decomposes, solidifies and releases a small amount of hydrogen sulfide gas. At the same time, the infiltrated alkali further reacts with the amino acids decomposed by protein, and the crystals of the generated salt are condensed in the egg white in a beautiful shape, like "pine flowers" one by one. Hydrogen sulfide gas reacts with minerals in egg yolk and egg white to generate various sulfides, so the colors of egg yolk and egg white change, and the egg yolk is dark green and the egg white is special tea green. Salt can shrink preserved eggs from their shells, increase their taste and prevent corrosion. The added plumbum can accelerate the ripening of preserved eggs, and promote the preserved eggs to shrink and shell. Tannin and aromatic oil in tea can solidify and color protein and increase the flavor of preserved eggs.