History of salted duck eggs

In the Northern and Southern Dynasties, it was recorded in the Book of Qi Yao Min: "Soak ducks in January, cook food, and use wine vessels." It's salted duck eggs. It has been recorded in all previous dynasties. It was sold in the market during the Northern Song Dynasty. China's Dream in Tokyo. Gaoyou salted duck eggs with double yellow eggs are especially precious. They won a high honor in 1909 Nanyang publicity conference, and now they are exported to more than ten countries and regions.