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.

The 17th century writer Fang Yizhi's "Little Knowledge of Physics (物理小識) states: "The eggs produced in Chizhou are salted with five kinds of tree ash.

The addition of calcium oxide and wood ash to the mixture lowers the risk of spoilage and also increases the speed of the process.

[7] Even though the traditional method is still widely practised, modern understanding of the chemistry behind the formation of century eggs has led to many simplifications in the recipe.

Today, soaking raw eggs in a solution of table salt, calcium hydroxide and sodium carbonate for 10 days, followed by several weeks of aging in an airtight container, can achieve a similar effect to the traditional method.

Facilitated by a high-pH environment, typically using a mixture of sodium hydroxide and salt, this method involves immersing raw eggs in a concentrated alkaline solution.

The high pH causes the egg white proteins, primarily ovalbumin, to denature and then reassemble into a globular network of fine strands.

This network forms through a combination of non-specific interactions, including long-range electrostatic repulsion and short-range attractions, resulting in the creation of a stable, elastic gel.

This technique illustrates a non-specific aggregation pathway common among globular proteins, effectively utilized to preserve the eggs and significantly alter their texture.

As an hors d'œuvre, the Cantonese wrap chunks of this egg with slices of pickled ginger root (sometimes sold on a stick as street food).

In Taiwan, it is popular to eat sliced century eggs placed on top of cold tofu with katsuobushi, soy sauce, and sesame oil, in a style similar to Japanese hiyayakko.

A variation of this recipe common in northern China is to slice century eggs over chilled silken (soft) tofu, add liberal quantities of shredded young ginger and chopped spring onions as a topping, and then drizzle light soy sauce and sesame oil over the dish, to taste.

Peeled century eggs are cut into quarters or eighths and simmered with the seasoned marinated lean slivers of pork until both ingredients are cooked into the rice congee.

Despite undergoing an alkaline preservation process, which could potentially impact their nutrient content, century eggs maintain a substantial amount of Vitamin B12.