Century Eggs

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Introduction: Century Eggs

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Whether you call them century eggs, hundred-year eggs, millennium eggs or whatever, these outlandish ova are a Chinese delicacy dating back centuries to the Ming Dynasty. The boastful name suggests these eggs take forever to make, this is a misnomer. Century eggs take about 4-5 weeks to make, a few minutes to work up the courage to open, and a few seconds to eat.

Traditionally century eggs were made by preserving chicken or duck eggs in a mixture of salt, lime and ash, then wrapping in rice husks for several weeks. During this time the pH of the egg raises transforming the egg, the chemical process breaks down some of the proteins and fats into smaller, more complex flavours. After curing the yolk of the egg turns a dark green and has a creamy consistency, while the white turns amber and is gelatinous. 

I chose a more modern method to achieve the same results: a salt and lye pickling solution, and encasing in modelling clay. After about a month my eggs were ready, and I'm happy to say they turned out perfectly!

Want to make your own? Of course you do! 
Enough talk, let's make some eggs!


Step 1: Supplies + Materials

supplies:
  • 100% lye/caustic soda (NaOH - sodium hydroxide)*
  • salt (NaCl - sodium cloride)
  • chicken egg (duck or quail egg)
.
materials:

* Technically lye is a corrosive, not poison. Though, it' can be labelled as either. It's incredibly dangerous to handle and can cause severe burns with contact to skin, there's also an inhalation risk. Use gloves and a respirator.
There's plenty of other foods that are made/prepared with lye, but use caution and common sense.
Always use pure, 100% lye (sodium hydroxide).

Step 2: Prepare Pickling Solution

Start by making the pickling solution, here's the basic breakdown:
  • 1L  - Water
  • 42g - Sodium hydroxide(NaOH)   (lye)
  • 72g - Sodium chloride(NaCl)   (salt)
On a scale weigh out the lye and salt. Over low heat dissolve the salt and lye completely in water. Bring the solution to a boil and allow it to cool down before use.

Place raw eggs into glass jar and pour the cooled pickling solution over eggs. Ensure all eggs are completely submerged. 

Step 3: Store

I wrote the date of submerging these eggs on my label, as well as the expected dates for encasing in clay, and eventual consumption. Label jar and store in a safe place, like the corner of your desk, so all your coworkers can gawk in disgust (or silent admiration). I also added a warning so my coworkers wouldn't mess with the jar while the eggs were pickling.

Leave eggs at 15-20°C (60-70°F) for about 10 days. Keep an eye on them to ensure they don't pop up above the solution and stay submerged.


Step 4: Remove From Brine

After about 10 days it's time to remove the eggs. Carefully pour out brine and pick out eggs, rinse with water then towel dry. The shells should still be hard.

You should be able to see some discolouration through the shells. 

Step 5: Encase

Traditionally century eggs were rolled in mud then wrapped in rice husks and buried for a few more weeks. In this modern version I simply wrapped the eggs in several layers of clear plastic wrap then encased in modeling clay. This inhibits oxygen from reaching the eggs while they cure.

Be careful when encasing in clay as not to break the eggs. After wrapping I put all the eggs into a resealable bag and left for another 2 weeks. 

Step 6: Crack Open

After about a month from the when the eggs were first put into the brine solution it's time to open them up. Carefully remove the clay encasement and the plastic wrap, then tap the egg to break the shell and gently peel away. The eggs should be completely transformed!

The whites of the eggs will now be a jelly-like translucent amber colour and the yolks a very dark green and with a texture much like a hard boiled egg. Take a look at picture 2 in this step to see the different consistency between the yolk and white in my egg-xperiment.

Step 7: Serve!

Century eggs are typically served mashed up in soupy rice. I made a steamy bowl and served it to my friends.

The taste was...interesting. The appearance is deceiving and almost put me off eating it altogether, but once I ate some it wasn't that bad. It tasted kind of like a hard boiled egg, only with a more complex flavour and a slightly mineral/metallic taste. I'm happy I tried this and think I would probably eat it again. You know, sometime later (much, much later).



Did you make your own version of century eggs? Post a picture in the comments below.

Happy making :)

4 People Made This Project!

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99 Comments

0
david.g.young.16
david.g.young.16

Question 7 weeks ago

Why is it necessary to boil the brine mixture before use?

0
IsiraDemari
IsiraDemari

Tip 5 months ago

This is two weeks after brine I cracked a single on it's own and their too soft at this stage, with the yolk not even set and only a thick cream in the core. I suggest doubling the time for curing after brine to a month or better at least! Will come back next month with either a tested egg or a complete egg depending how it turns out.

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JeffH344
JeffH344

1 year ago

Thanks for sharing this! I read that the NaoH should be stored in plastic not glass though - is that true?

0
IsiraDemari
IsiraDemari

Reply 6 months ago

I'm testing mine out in just a glass jar, so in ten days I'll let you know if it went well! I know you can get the right grade containers for it online if your running it on the safe side.

0
mikeasaurus
mikeasaurus

Reply 1 year ago

Plastic is best. Storing sodium hydroxide in glass can cause a reaction and frost the glass. For the length of time the eggs are in there I don't see this as an issue, but the right protocol is to use plastic.

0
anthonymaw
anthonymaw

1 year ago

Or you could just go down to your local Chinatown or Asian food market and buy them off-the-shelf and ready-to-eat. They might also be served in Chinese restaurants with the rice-broth more commonly known as "congee". Enjoy!

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IsiraDemari
IsiraDemari

Reply 6 months ago

I wish lol, in my area the nearest asian market is in a different state and don't have them, but when j could get them I loved them!

1
MelBermachea
MelBermachea

Question 1 year ago

Hello sir, can you help me. My eggs yolk is not totally transformed. still watery.

What do you think is the problem?

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IsiraDemari
IsiraDemari

Answer 6 months ago

Maybe leave them for another week to cure?

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MrKibblesworth
MrKibblesworth

Question 6 months ago

Why are my whites green two weeks in and not translucent brown? I coated my chicken eggs with beeswax btw. I didn't seal them in a plastic bag afterwards. They are sitting in the pantry in egg cartons. I think they taste like they're supposed to but unless I compare them to store-bought ones I won't know for sure.

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IsiraDemari
IsiraDemari

Answer 6 months ago

If it's a cracked egg that got air into it or the solution then it's probably gone bad, I recommend opening one of the others to check! I've never seen one go green before so that's worrying.

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MrKibblesworth
MrKibblesworth

Answer 6 months ago

They are less green on a white plate I found. So pretty.

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MrKibblesworth
MrKibblesworth

Answer 6 months ago

Also, this egg cracked before sealing it in wax. Maybe that affected it, no? I have 20 that were not cracked. Maybe I should bust one open and see if there's a difference thought I have my doubts that there will be.

0
IsiraDemari
IsiraDemari

6 months ago

I just started the process today I shall return in 45 days to tell you how things went! 10 eggs in total, I'll he using the plastic wrap and some craft clay I have a ton of, but unlike your recipe I'm doing 35 days added after the brining phase, so they will be ready in December! This is something I find interesting, the longer you let them stay in the clay to cure, the darker and more solid they become. (From asking my exes mom, Vietnamese family). I honestly was terrified to handle any of the stuff but I am extremely eager now to see how it goes!

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GretaNG
GretaNG

1 year ago

Thanks for the guide, Mike. I’m on day 10. Just happy the egg came out of the jar I put it in, from it’s growth spurt. Now to use ash or clay is my next step. Thank you.

1
Millie Lim
Millie Lim

Question 1 year ago on Step 1

Is it fine to soak the century egg in the pickling solution more than 10days?What will happen?

0
chiao
chiao

9 years ago on Introduction

Yes! I love these! Unfortunately, my wife just bought some, so she won't let me make them right now. I like to eat them sliced with soft tofu and thick soy sauce. Mmm! Now I just need to learn to make my own rice wine and tofu...

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100YearsAnEgg
100YearsAnEgg

Reply 2 years ago

I hate when my wife doesn't let me make eggs right now!!!

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RayL4
RayL4

6 years ago on Introduction

Alright! I'm gonna start the process tonight! Thanks so much for this write-up! How in the world did you even get the asian century egg sensei's to give up their secrets??

0
100YearsAnEgg
100YearsAnEgg

Reply 2 years ago

Keep us posted on how it goes!!