The origin of the method for creating century eggs likely came about through the need to preserve eggs in times of plenty by coating them in alkaline clay, which is similar to methods of egg preservation in some Western cultures.[3] The clay hardens around the egg and results in the curing and creation of century eggs instead of spoiled eggs.
According to some, the century egg has over five centuries of history behind its production. Its discovery, though not verifiable, was said to have occurred around 600 years ago in Hunan during the Ming Dynasty, when a homeowner discovered duck eggs in a shallow pool of slaked lime that was used for mortar during construction of his home two months before. Upon tasting the eggs, he set out to produce more — this time with the addition of salt to improve their flavor — resulting in the present recipe of the century egg.