Century eggs, also known as preserved eggs, pidan, or thousand-year eggs, are a Chinese delicacy made by preserving duck eggs in a mixture of clay, ash, salt, quicklime, and rice hulls for several weeks or months. This process transforms the eggs, giving the white a translucent, jelly-like texture and the yolk a creamy, dark green or dark brown colour. The flavour is described as savoury, umami, and slightly pungent.