Century eggs are often referred to as a Chinese delicacy by westerners. But in Vietnam it is not that expensive or rare, if you know where to look -- egg shelves at supermarkets and egg stalls in markets. One costs just around VND5,000.
2. They are most popular in Ho Chi Minh City, which has the country's largest Chinatown, Cho Lon (Big Market). However, not everyone knows about them since their popularity is virtually limited to the Chinese-Vietnamese community and people who have connections with it.
3. Vietnamese call them trứng bách thảo or trứng bắc thảo for which explanations by no means are available. But the names can be understood as a reference to the use of herbs in the eggs' preservation.
4. They are also known as bách nhật trứng, literally translated as 100-day eggs, which sounds much younger than their English names -- century eggs and even millennium eggs. In Chinese, they are called pidan among many other names.
5. Regardless of their name, century eggs are not that old, only their history is. They are believed to date back to 600 years ago when someone in China's Hunan Province accidentally discovered duck eggs in a pool of slaked lime used as mortar, where they must have been lying for a long time. Upon discovering the "preserved" eggs' unique flavors, they decided to produce them with the addition of salt.
6. The recipes for making century eggs are not always the same, as one can make a few adjustments here and there. The most common one involves preserving the eggs -- duck, chicken or quail -- in a mixture of clay, wood ash, rice husk, quicklime, and salt for 2-3 months.
Another recipe involves herbs like bo ket (Chinese honeylocust fruits), green tea powder, and cinnamon powder.
7. Century eggs are recognizable by their dark brown, translucent and jelly-like whites and creamy (sometimes runny) yolks with different colored layers ranging from dark green to gray. If you are lucky, you will find eggs with pine-like patterns in its white.
8. The eggs' taste is unmistakably pungent with the odor of sulfur and ammonia. But once you get used to it, it is very easy to get addicted the unusual taste and smell.
9. In Ho Chi Minh City, century eggs are often served as an appetizer by themselves or with other foods like chả (pork paste). People also love them as a beer snack. The eggs are often eaten with dried shrimps and pickled củ kiệu, a species of wild onion known as Chinese or oriental onion.
10. It is also a common ingredient in rice porridge which is popular at Chinese restaurants around the city, especially in Districts 5 and 11, where Chinatown is situated.
11. Street stalls that sell soups with century eggs are also popular. They can be even found downtown like the ones next to Saigon Notre-Dame Basilica and the intersection of Mac Dinh Chi and Nguyen Van Thu streets in District 1.
12. The nutritional benefits of century eggs are still debated. Some believe the herbs make them healthy. However, some scientific studies have found that the preservation detracts from their nutritional value.
Century eggs are also infamous in both Vietnam and China, with news reports saying their makers use toxic chemicals to speed up the process.
13. Should you try century eggs? Well, you should. Even though the idea may sound repulsive to some, at the end of the day it is just another unusual dish. Why not get a taste of it to see what it is like and get over your curiosity? You might even love it!