Salted Duck Eggs
Duck eggs cured in brine until the yolk goes dense, orange and oily and the white goes fiercely salty. The prized yolk is the whole point - it's what goes in mooncakes and zongzi. Genuinely home-makeable: it's brine, a jar, and 30 days of doing nothing. The only hard part is finding duck eggs, and the reason it must be duck is in the notes.
Asian · Chinese · Condiment · Eggs · Marinated Eggs
Duck eggs cured in brine until the yolk goes dense, orange and oily and the white goes fiercely salty. The prized yolk is the whole point - it’s what goes in mooncakes and zongzi. Genuinely home-makeable: it’s brine, a jar, and 30 days of doing nothing. The only hard part is finding duck eggs, and the reason it must be duck is in the notes.
Ingredients
- 12 duck eggs, very fresh, washed and dried (check each for cracks - discard any that are cracked)
- 1.5 litres water
- 350 g coarse salt (about 20-23% brine)
- 2 star anise (optional)
- 1 cassia stick (optional)
- 2 tbsp Shaoxing wine or baijiu (optional - traditional, and said to help the yolk oil)
- A clean glass jar large enough to hold the eggs submerged
Directions
Key ingredients
- Make the brine. Boil the water with the salt (and spices, if using) until the salt is fully dissolved. It should be saturated - a raw egg will float. Cool it COMPLETELY. Hot brine will start cooking the eggs.
- Check every egg for cracks. A cracked egg in brine is a spoiled egg, and worse. Discard any that aren’t perfect.
- Pack the eggs into the clean jar. Pour the cold brine over to cover completely. Add the wine if using.
- Weigh them down so they stay submerged - a small water-filled zip bag on top works well. Any egg above the brine line will spoil.
- Store at cool room temperature, out of the sun, for 30 days. (Longer = saltier. 40 days gives a very firm yolk; past 50 it gets punishing.)
- Test one at day 30: boil it for 10 minutes, cut it open. The yolk should be firm, deep orange, and slightly oily; the white should be very salty and still soft. If the yolk is pale and soft, give the rest another week.
- To use: boil 10 minutes and eat with congee, or crack raw and use just the yolk in mooncakes, zongzi, or steamed with pork.
Notes
Why duck eggs
Duck eggs have a higher fat content and a larger, firmer yolk, and the yolk fat is what produces the prized texture - dense, sandy-oily, deep orange. A salted chicken egg works but gives a smaller, drier, paler yolk. It’s not the same thing.
The science of the gradient - and it’s the best evidence on this whole site
Duck eggs brined for 35 days, measured:
| Fresh | After 35 days | |
|---|---|---|
| Egg white | 0.47% salt | 8.23 - 11.61% |
| Egg yolk | 0.32% salt | 2.25 - 3.29% |
Thirty-five days, and the yolk has barely crawled to 2-3% while the white is at 8-12%. The gradient is enormous and it persists for over a month. That’s why the white is aggressively salty and the yolk is rich rather than briny - and it’s proof that no marinade, on any timescale you’d tolerate, equalises an egg.
(Source: Xu, L. et al. 2017, PLOS ONE 12(8):e0182912.)
The other traditional method
Salt-mud/charcoal packing: coat each egg in a paste of salt and charcoal powder or clay, then pack in a jar. Messier, works the same way, and is what you’ll see in older Chinese kitchens. The brine method is easier and I’d start there.
Safety
Submerged, salted, and unbroken is the safe configuration. Never use a cracked egg. If any egg floats free of the brine, discard it. If the brine goes cloudy, ropy or smells of anything but salt and spice, start over.
See Century Egg Congee.