<Tr> <Th_colspan="2"> (show) Transcriptions </Th> </Tr> <Tr> <Th> Romanization </Th> <Td> seiki no tamago </Td> </Tr> <P> Century egg or Pidan (Chinese: 皮蛋; pinyin: pídàn), also known as preserved egg, hundred - year egg, thousand - year egg, thousand - year - old egg, millennium egg, skin egg and black egg, is a Chinese preserved food product and delicacy made by preserving duck, chicken or quail eggs in a mixture of clay, ash, salt, quicklime, and rice hulls for several weeks to several months, depending on the method of processing . </P> <P> Through the process, the yolk becomes a dark green to grey color, with a creamy consistency and strong flavor due to the hydrogen sulfide and ammonia present, while the white becomes a dark brown, translucent jelly with a salty flavor . The transforming agent in the century egg is an alkaline salt, which gradually raises the pH of the egg to around 9--12, during the curing process . This chemical process breaks down some of the complex, flavorless proteins and fats, which produces a variety of smaller flavorful compounds . </P>

How do you make a 1000 year old egg