Updated from an entry published last year right around the time of the Chinese Lunar New Year.
You’ll find them sliced thinly and served alongside cold meat and pickled jellyfish in Chinese restaurants. They’re called century eggs, a popular Chinese delicacy, and they are regular eggs really except that they have undergone a curing and preservation stage. Century eggs are usually duck eggs.
Ideally, century eggs are made by storing raw eggs for a few months in a mixture of wood ash, salt, lime, and maybe tea with rice straw or clay. The alkaline chemicals raise the pH of the egg to 9-12 or even higher and break down some of the proteins and fats in the egg into flavorful molecules. [Source]
That’s the traditional way of preserving the eggs. The modern method consists of “soaking the eggs in a brine of salt, calcium hydroxide, and sodium carbonate for 10 days followed by several weeks of aging while wrapped in plastic is said to achieve the same effect as the traditional method.”
I was a young child when my father first introduced me to century eggs and I was immediately hooked. It may have something to do with attitude — I was raised to believe that there’s nothing scary about trying new things and just because something was unfamiliar didn’t mean it was disgusting. Or it may be due to the natural adventurous spirit of a child who has not yet formed prejudices against unfamiliar things. Or, perhaps, it was both. Whatever the reason, I loved the gelatinous texture of the egg white that has turned a deep reddish brown hue. I loved even more the creamy texture of the yolk that was no longer yellow but a gray-greenish mass that is sticky and pasty towards the center.
How are century eggs eaten? You can just crack the shell, slice the eggs and enjoy them with your favorite dipping sauce. Soy sauce and vinegar with a little ginger is a popular accompaniment. Or serve on a plate of hors d’œuvre with sliced roast duck, suckling pig and char siu pork. You can add them to salads and congee too.
Many say that the appreciation of century eggs is something acquired. I say just keep an open mind.