Salty duck eggs (xian ya dan
) are a common sight in the kitchen of Chinese homes. These are simply preserved whole raw duck eggs which have been brined in salty water or wrapped in a heavily salted clay for some time. Note that these eggs are different from the infamous black
colored thousand year eggs
(pidan) even though both can be labeled as "preserved eggs." Nor are salty duck eggs related to Chinese tea eggs
(cha ye dan). Also note that salty duck eggs are not the pickled eggs
one sometimes sees floating in giant jars at American deli counters.
After a month of brining, the egg yolk will solidify and will be a firm spheroid. The eggs whites, however, will remain a liquid and will have absorbed much of the salt. The yolks should be rich and oily with only a slightly salty flavor. The texture is somewhat grainy and perhaps most similar to an extremely oily and soft chunk of Parmigiano Reggiano. The best quality yolks will also be slightly translucent--perhaps from the oil content--and vividly red in color. Poor quality yolks are indistinguishable from the yolks in normal hard boiled chicken eggs. Unfortunately, the best eggs will often also have whites that are nearly inedible due to the salt content.
Why duck eggs and not chicken eggs? Duck egg yolks usually have a higher oil content which is prized in the finished product. Some Chinese people also believe the shell of duck eggs is more porous and make preserving the egg much easier.
Uses for Salty Duck Eggs
The uncooked yolks can be used as ingredients in mooncakes or stuffed in zongzi (rice dumpling) of Dragon Boat Festival fame. A common recipe I've seen circulated among Chinese Buddhists also calls for a mixture of mashed yolks and grated parmesan cheese to produce a vegetarian "fish roe." But at the most basic level, the eggs are usually hard boiled and eaten with plain congee to offset the saltiness. Add some pickled vegetables, and this would be considered a light meal. This sort of meal, however, is considered quite "homey" and plain and, in my experience, would never be served in a normal restaurant or offered to dinner guests in a Chinese home.
Where and How to Buy
In North America imported salty duck eggs can be purchased at Asian markets in styrofoam cartons of six or floating in plastic jars of brine. Until around the mid-1990's one could also purchase eggs that had been preserved using salted clay. These eggs would normally be encased in a layer of black clay which had to be rinsed off prior to cooking. However after a lead poisoning scare, this style of salted duck eggs have been a somewhat rare sight US Asian markets.
Eggs imported from Hubei Province in China are traditionally considered the "best" since that region has many lakes. Ducks in that region are allowed to roam free and feed on snails and bugs in and around the water. This sort of diet allows ducks to produce more flavorful and richer eggs. Brands of eggs from Hubei will advertise the fact on their labels. However storage conditions and length of brining will greatly affect the quality of the eggs. Therefore, eggs from Taiwan, Fuzhou, or Guangzhou may be quite good as well.
Even though salty duck eggs are preserved, their quality deteriorates with time after the brining process. The yolk will "disintegrate" into the white, and one will be left with only a pale yellow splotch in the middle of the egg. Eggs like that are still edible, though.
Do it Yourself
It's quite easy to make salty duck eggs at home. The only difficulty would be obtaining fresh duck eggs--especially those laid by free-range ducks that have fed on grubs and snails. Chicken eggs can be used but will produce less than stellar results. What you need:
- Duck eggs (a half dozen to a dozen is a good number)
- A lidded glass jar capable of holding all the eggs with space left over
- A cooking pot with almost the same capacity as the jar
- A large quantity of salt (ordinary salt is fine--no need for fancy Kosher salt)
- Water (from the tap is fine)
Fill up the cooking pot with water and bring to a full boil. Turn off heat. Mix in enough salt to saturate the water. In other words, there should be a layer of undissolved salt on the bottom of the pot. More salt is better than less salt because the eggs may go bad if the brine is not salty enough. Let the salted water completely cool. Place the eggs into the jar. Fill the jar with the salted water, and make sure all the eggs are completely submerged. Note that you want the water to fully cover the eggs and you should see a layer of salt settled on the bottom of the jar. Cover jar with the lid. Place the jar in a cool, dry place like a cupboard or underneath one's bed. After two weeks try one of the eggs. The length of time for brining depends on the salinity of the water, the size of the eggs, and whether or not you plan on consuming the whites. But normally this period should not exceed two months.
My parents are originally from Hubei Province, and they used this method to make salty duck eggs at home with quite good results. We did, however, also raise our own ducks in the backyard much to the chagrin of the neighbors.