What looks like your typical egg fare but tastes incredibly rich and jam-packed with umami is the result of preserving a duck egg for over a month. Cut into a hard-boiled or steamed salted duck egg and you’ll find a white that is much denser and a yolk that is slightly grainy but less chalky than a normal chicken egg.
Fuchsia Dunlop, an English food writer who specializes in Chinese cuisine and has written several comprehensive cookbooks on the subject, including the new Land of Fish and Rice (she’s also a contributor to the premiere issue of Cured), tells Food Republic that the Chinese, specifically people from the Jiangsu and Zhejiang provinces on the eastern coast of China, have been curing eggs for about 1,400 years.
“There’s a very well-known sixth century agricultural treatise, which includes a description of how to make a kind of salt egg with some kind of tree bark,” she says. “It’s basically an infusion to which salt is added, and the eggs are preserved in that.”
Nowadays, salted eggs are prepared with duck eggs, covered in a mud paste or ash or, most commonly, in a salt brine. While other poultry eggs could be preserved in the same way, Dunlop says that those from ducks are the only ones used in practice. Andrew Wong, chef and owner of A. Wong in London, reasons that duck yolks are most commonly used in this way for their rich yolks.
Wong says when using a salt brine, the eggs sit for 40 to 50 days. Both Dunlop and Wong mention adding baijiu (白酒), or Chinese rice wine, to the brine or wiping the shells clean with it before preserving. Dunlop also says that star anise or Szechuan peppers are sometimes added to the brine “for extra fragrance.”
Once cured and cracked open, Dunlop says, one will find a solid, waxy golden yolk with a slightly cloudy, runny white. Because of the contrast in textures, the white and yolk are often used in different fashions or altogether separately in dishes, such as Cantonese mustard green and pork soup.
“With that, you cut up the egg yolk and you put the little pieces into the soup and drizzle in the whites so you get lovely little fluffy flowers of white,” Dunlop says. “The soup doesn’t really need any salt for seasoning — it’s already a seasoned soup.”
Whole eggs are often steamed or hard-boiled and served with breakfast congee. The yolks, on the other hand, are treated like buried gems, steamed whole into Chinese tamales or zhongzi (粽子), finely chopped pork and shiitake mushrooms wrapped around a thick layer of glutinous rice, which is then wrapped in bamboo leaves and steamed. They’ll also represent the roundest and brightest moon of the year when placed in the center of sweet mooncakes, a dessert made of lotus paste traditionally eaten during the Mid-Autumn festival. A preparation that’ll showcase their super-savory side is known as jinsha (金砂), which translates literally to “golden sand.” After steaming, the yolks are finely chopped and fried up in oil in a wok.
“They get fluffy and yellow, then you toss in some other ingredient — maybe some pumpkin, which you’ve already cooked, or sweet corn or shrimps in their shells,” Dunlop says. “They’re called golden sand dishes because you get these pieces of food to have this wonderful coating of delicious umami, gold morsels of egg.”
A steamed salted egg can simply be enjoyed on its own or “with a little fag [cigarette] with drinks,” as Dunlop would have them.