[H3]I didnt know that 49er, I googled it. I thought they were all the same.[/H3] Heres an excerpt, and a link to it, lots more info.
[H3][A href="vny!://everything2.com/index.pl?node_id=1459145"]vny!://everything2.com/index.pl?node_id=1459145[/A][/H3] [H3]鹹鴨蛋[/H3]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 [A title="Black egg" href="vny!://everything2.com/index.pl?node=Black%20egg"]black[/A] colored [A title="Thousand year eggs" href="vny!://everything2.com/index.pl?node=Thousand%20year%20eggs"]thousand year eggs[/A] (pidan) even though both can be labeled as "preserved eggs." Nor are salty duck eggs related to [A title="Chau Yep Ahn: Tea Eggs" href="vny!://everything2.com/index.pl?node=Chau%20Yep%20Ahn%3A%20Tea%20Eggs"]Chinese tea eggs[/A] (cha ye dan). Also note that salty duck eggs are not the [A title="pickled eggs" href="vny!://everything2.com/index.pl?node=pickled%20eggs"]pickled eggs[/A] 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 [A title=Parmigiano href="vny!://everything2.com/index.pl?node=Parmigiano"]Parmigiano Reggiano[/A]. 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.
Where and How to Buy In North America imported salty duck eggs can be purchased at [A title="Asian Market" href="vny!://everything2.com/index.pl?node=Asian%20Market"]Asian markets[/A] 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 [A title=Hubei href="vny!://everything2.com/index.pl?node=Hubei"]Hubei[/A] Province in [A title=China href="vny!://everything2.com/index.pl?node=China"]China[/A] are traditionally considered the "best" since that region has many lakes. Ducks in that region are allowed to [A title="free range" href="vny!://everything2.com/index.pl?node=free%20range"]roam free[/A] 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 [A title=Taiwan href="vny!://everything2.com/index.pl?node=Taiwan"]Taiwan[/A], [A title=Fuzhou href="vny!://everything2.com/index.pl?node=Fuzhou"]Fuzhou[/A], or [A title=Guangzhou href="vny!://everything2.com/index.pl?node=Guangzhou"]Guangzhou[/A] 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.