Century eggs, also called hundred-year egg, thousand-year egg, or century egg (皮蛋 pidan in Chinese), are eggs traditionally preserved in Chinese cuisine. Despite the name, they are not 100 years old; they are usually matured for a few weeks to a few months.
What exactly are century eggs?
The century egg is an egg preserved in an alkaline medium, which alters:
- the color
- the texture
- the flavor
- the smell
Typically used are:
- duck eggs (the most common)
- chicken eggs
- quail eggs
After the curing process, the result is:
- egg white: becomes translucent, gelatinous, dark brown or amber in color
- egg yolk: becomes creamy, dark green or grayish, sometimes with a firmer texture on the outside
How are century eggs made?
Traditional method
Historically, eggs were wrapped in a paste composed of:
- wood ash
- quicklime (calcium hydroxide)
- salt
- tea (in some recipes)
- rice straw or rice husk for external protection
The egg is covered with this paste, rolled in straw, and left curing for weeks or months.
The mixture is highly alkaline, which:
- increases the egg's pH
- denatures proteins
- transforms the egg white's texture into a gel
- makes the yolk denser, creamier, or almost buttery
Modern method
Currently, in industrial-scale production, the following can be used:
- controlled alkaline solutions
- airtight containers
- well-defined curing times
This improves flavor standardization and food safety.
The flavor of century eggs
The flavor is intense and peculiar, and can be surprising for those trying it for the first time.
Common notes described:
- pronounced umami flavor
- slight earthy or marine taste
- ammoniacal or sulfuric notes (somewhat reminiscent of well-aged cheese)
Many people associate the aroma with:
- strong cheeses
- fermented or aged foods
How to eat century eggs
They are consumed in various ways in Chinese cuisine and other Asian countries.
Common ways of consumption:
-
Plain, in slices
- Served as an appetizer, with pickled ginger and soy sauce.
-
Century egg and lean pork congee (皮蛋瘦肉粥)
- A very popular rice porridge for Chinese breakfast.
-
Salads and cold appetizers
- Century egg with cold tofu, scallions, soy sauce, and sesame oil.
-
In stir-fried dishes
- Mixed with vegetables or meats in small quantities to add flavor.
Origin and history
- Century eggs are a traditional dish in Chinese cuisine, with records of consumption dating back at least to the Ming dynasty.
- Today, they are found in countries like China, Taiwan, Hong Kong, Vietnam, Thailand, and in Chinese communities around the world.
You can see more historical and cultural details here:
Are century eggs safe?
Under normal conditions, yes, they are safe for consumption, provided that:
- they are produced by reliable sources
- they are stored properly
- they are consumed within the expiration date defined by the manufacturer
About “lime-preserved egg” and toxicity
In the past, some artisanal productions used improper additives, such as lead-based compounds to accelerate the curing process, which is dangerous. Today:
- the use of lead compounds in food is not permitted
- reputable industrialized products follow sanitary standards and do not use these agents
Therefore, it is ideal to:
- buy century eggs from well-known brands
- check the label, origin, and local sanitary certifications
Nutritional value
The century egg is still, basically, an egg:
- rich in proteins
- contains fats (including cholesterol)
- possesses vitamins and minerals similar to those of a common egg
Preservation alters the texture and flavor more than the basic nutrient profile, although:
- there may be changes in some amino acids
- the sodium content may be higher, depending on the process
Who should be careful when consuming?
Some groups should consult a healthcare professional before including century eggs in their diet:
- people with severe sodium restriction
- people with hypercholesterolemia under strict control
- pregnant women and immunocompromised individuals (the same safety recommendations for eggs and animal products in general apply)
Where to buy century eggs
You usually find them in:
- Asian markets / Asian product stores
- large supermarkets with an international section
- online stores specializing in Asian ingredients
They usually come in:
- packages with the shell still preserved
- or already peeled, vacuum-sealed, ready for consumption
How to store
- Always follow the packaging instructions.
- Many industrialized products can be kept at room temperature before opening, and after opening should be refrigerated.
- Consume within the indicated period after opening the package.
Quick summary
- They are not actually 100 years old.
- They are eggs (usually duck) preserved in an alkaline medium for weeks or months.
- They have a brown gelatinous egg white and a creamy dark green yolk.
- They have a strong, umami flavor, reminiscent of fermented foods or aged cheeses.
- They are traditional in Chinese cuisine and other regions of Asia.
- When made according to sanitary standards, they are safe for consumption.