Quanlin salted duck eggs [Photo/WeChat account: jnwhlyj]

Quanlin salted duck eggs are produced in Quanlin town, which is 25 kilometers east of the downtown area of Sishui county in Jining, East China's Shandong province.

According to historical records, the egg salting technique dates back to the Southern and Northern Dynasties (420-581). It is said that the egg was favored by Emperor Qianlong of the Qing Dynasty (1644-1911) so much that it had since become a tribute to the imperial court.

The delicacy uses only fresh duck eggs that are produced around local spring clusters. According to professional evaluations, the natural springs where the ducks produce the eggs are unpolluted,  so the ducks that eat water weeds, fish and shrimps are very healthy and nutritious.

The egg yolk is red and rich in fat, protein, amino acids, and various minerals and vitamins that are essential to humans.

The eggs are cleaned, dried (not under the sunshine) and evenly covered with a specially made red mud from the Majiazhuang village, 5 kilometers south of Quanlin town.

The mud-covered duck eggs are sealed in a jar filled with a mixture of spices including ginger, star anise, Sichuan pepper, cinnamon and salts that have been boiled in water for 20 minutes. It takes two months in winter or about 20 days in summer until the eggs are ready to be served at dining tables.

Traditional Chinese medicine believes that Quanlin salted duck eggs can help clear excessive heat from the lungs and the yolk oil is effective in treating children's digestive problems.