Are 100 year old eggs safe to eat?

In this brief guide, we are going to answer the question, “Are 100 year old eggs safe to eat?”. We will also discuss some precautions to take before eating 100 year old eggs.

Are 100 year old eggs safe to eat?

Yes, it is safe to eat 100 year old eggs. 

100 year old eggs, also known as century eggs, millennial eggs, ancient eggs, and 1000 year eggs are a Chinese delicacy. 100 year old eggs are actually duck, chicken, or quail eggs preserved with different techniques that change their taste and texture.

Although the name implies they are 100 years old, they are only preserved for a few weeks or a few months. 

What precautions should you take before eating 100 year old eggs?

  • Make sure that the eggshell is smooth without any cracks and openings.
  • Some 100 year old eggs have been preserved using lead. Lead can be harmful to your health. If possible, find out what ingredients were used to preserve the eggs. 

How to eat a 100 year old egg?

  • Wash off the outer layer that contains a mixture of clay, mud, and rice husks. Most store-bought century eggs are already cleaned. If the eggs are not cleaned, soak them in water for a few minutes and then rub off the mud and rice husks.
  • Crack the egg open just like you would crack a hard-boiled egg. Then peel off the eggshell.
  • Slice the egg and eat it a little bit at a time. The flavor of the egg can be overpowering and unappealing if you eat a big portion at once.
  • 100 year eggs are mostly eaten raw and it is safe to eat them raw. They are usually eaten side by side with a dish like rice, tofu, or porridge. You can also eat just the egg.
  • You can fry or steam the 100 year old egg if you wish to. 

How does a 100 year old egg smell, look, and taste?

100 year old eggs don’t smell good. If you are trying these for the first time, you might be put off by the smell. They smell like a combination of ammonia and sulfur.

The egg white will be black and the yolk will be greenish-gray color. It can look very unappealing to a first-time user. Some century egg yolks are runny while others are thick.

The taste of a 100 year old egg is said to be better than its smell. Many have compared the taste to that of cheese with a smooth texture.

How to find out if a 100 year old egg has gone bad?

It is very difficult to identify if a 100 year old egg has gone bad, especially if you are unaccustomed to its usual smell and taste.

If you notice any mold growing on them, do not eat it. It is very rare for bacteria and mold to grow on the eggs because of the high pH.

On the plus side, 100 year old eggs do not go bad easily. As long as the eggshell is intact, the egg should be safe to eat. To be safe, only eating eggs will have intact eggshells and always check on how the chemicals are used to preserve the egg.

How are 100 year old eggs made?

There are a few different ways to make 100 year old eggs. 

Traditional method: The eggs are rolled in a mixture of wood ash, salt, quicklime (calcium oxide), tea, and rice husks. The eggs are then stored in jars for a few months. Quicklime is alkaline and this raises the pH of the eggs. This is what causes the black color of the eggs and gives a sulfur-ammonia smell.

Industrial method: The industrial method uses different preservatives. Salt and lye are used to make 100 year old eggs. Some industries add lead oxide to speed up the preservation process. Lead is a heavy metal that is poisonous. It is important to never eat 100 year old eggs made with lead. 

Some companies use zinc oxide instead of lead oxide. Zinc is not poisonous but too much of it can be harmful to health.

From where can you get 100 year old eggs?

100 year old eggs won’t make you sick. If you are purchasing 100 year old eggs, always purchase from a reputable supplier who lists the ingredients. You can also try out 100 year old eggs from a well-rated restaurant. They will be available in Asian and Chinese restaurants.

You can also make 100 year old eggs at home. But it will take about 40 days for the eggs to be ready to eat. Check out this recipe for making 100 year old eggs at home. 

Other FAQs about Eggs that you may be interested in.

Are 3 eggs for breakfast too much?

Are bad eggs dangerous?

Are bloody eggs safe to eat?


In this brief guide, we answered the question, “Are 100 year old eggs safe to eat?”. We also discussed some precautions to take before eating 100 year old eggs.