Now long ago, some one listed perserved egg as one of the most disgusting food and unfornately displease a lot of Chinese who believe preserved eggs are delicious food. Well, the eggs look ugly from outsie to inside when it is not processed, but it actually is made from duck eggs. I have no idea how it turned to this color while being preserved, but the original taste of it not good, I have to admit it. Chinese do not cook it neither, what they do is to mix it with vinegar and sesame oil and sliced garlic. These things help improve the taste, and many Chinese love it espcially in hot summer.