Which Chinese preserved egg is also called a hundred-year egg in English?

The Chinese preserved egg also called a hundred-year egg in English is a century egg. It is made by curing duck, chicken, or quail eggs in an alkaline mixture traditionally containing clay, ash, salt, quicklime, and rice hulls. The process takes weeks to several months, not a literal hundred years.

During curing, the egg white becomes dark brown, translucent, and jelly-like, while the yolk turns greenish-gray and creamy. Alkaline chemical reactions alter the egg’s proteins, fats, and flavor compounds, creating its distinctive savory, salty, and strongly aromatic taste.

Century eggs have been part of Chinese cuisine since at least the 17th century, although older preservation methods may have preceded written records. They are commonly served sliced with congee, tofu, or pickled ginger. The names hundred-year egg and thousand-year egg are colorful English descriptions, not claims about the egg’s actual age. Balut and salted duck egg are different preserved or prepared egg foods.