On a recent trip to China, a co-worker dared me to swallow a 1000 year old egg showcased at a local night market. My response was probably a normal one to some Westerners. My bold, gutsy and daring self decided to “just say no.” Considered a delicacy in many parts of Asia, the exotic, preserved egg turns out to attract many followers and even highlights some added health benefits. There are many styles of Asian cuisine whether it be Mongolian, Cantonese or Hunan and most will find foods from the Far East are quite flavorful. The 1000 year old egg, to some sounding a bit like an oddity, is actually a favorite, tasty treat over the globe.
It has been called many names--century egg, preserved egg, Ming Dynasty egg or hundred year egg. The exotic appetizer, you guessed it, is really not that old. Referred to as pidan, meaning “leathered egg” in Chinese, the delicacy is usually a chicken, goose, or duck egg. The duck egg is the preferred option. But to no surprise, the egg’s name, “1000 year old egg” isn’t really the truth. The egg is first soaked in brine for approximately 10 days then wrapped in plastic to ferment for 100 days up to 8 months.
Over 600 years ago during the Ming Dynasty era, the story goes that a hungry man discovered the delicacy. He came upon the eggs soaking in pickled lime, a compound used as mortar for building a house foundation. The man added some salt to the egg and "Bon Appetit!" He began producing more of the delectable egg. The production began in a shallow pool coated with wood ash, salt, tea, lime and clay. Buried in rice husks, the egg proceeds with fermentation, stashed away for a good 5 months. The lime causes the egg to age turning the yellow yolk into an interesting shade of gray. The chemical components in the fermentation disturb the proteins, breaking down the amino and fatty acids. The alkaline level raises the PH level to almost a 12 producing a sulfur, ammonia like odor. Today, the egg eaten by those with an acquired taste, is preserved with sodium and alkaline hydroxide.
Taste and Texture and Color
The aged egg is ready when the coating is about a fourth of an inch thick. The egg is unwrapped and peeled, highlighting a smooth coffee colored white with a gelatin like texture. The yolk, once exposed to to air loses some of its greenish gray color. It is noticeable to see different sizes of rings surrounding the yolk and don’t be alarmed at greenish specks clinging to the inside of the shell. The odor can be worrisome to many, but the pungent taste, somewhat salty, is addictive. Rumor has it the egg is used as an aphrodisiac, but many consider it a high protein, healthy snack.
The century egg has similar nutritional properties to a fresh egg. Although the preserved egg may have more protein and lesser carbohydrates than a fresh egg, other components remain the same. The egg is packed with vitamin A and B vitamins including B-12 and riboflavin. The egg is also an excellent source of iron, selenium and phosphorus. Eggs are a good source of vitamin D. Regular consumption of preserved eggs may lower blood pressure, improve appetite, vision and the liver, but further trials are needed.
The preserved egg can be found in Asian markets and restaurants wrapped in bamboo or lotus leaves, served with white sticky rice or aside sliced thinly cold cuts and pickled food. Usually prepared boiled, steamed, poached or even fried, it is served as an appetizer or breakfast dish usually atop congee, an Asian rice porridge. It is complimented with ginger, soy or sesame oil and maybe eaten by itself, with bean curd or tofu. The eggs maintain freshness for 2 weeks at room temperature or up to one month stored in refrigeration.
www.jbc.org; Katherine Blunt, Chi Che Wang, University of Chicago, Lab of Food Chemistry, Department of Home Economics