Donkey-Hide Gelatin

Donkey-hide gelatin, ass-hide glue or ejiao is an animal glue obtained from the skin of the donkey by soaking and stewing, with Latin name colla corii asini. It is used in traditional Chinese medicine, where ejiao means the gelatin of Dong'e County in Shandong, the source of the name. It is made in several coastal provinces, including Jiangsu, Zhejiang and Shandong. A source from around 1723 says it was traditionally made in late autumn and winter from the skin of a recently killed, well-nourished black donkey, and that much fake ejiao, made from the skins of mules, horses, camels and pigs, was also sold. Li Shizhen wrote in the Bencao Gangmu that ejiao, once made from beef skin, had by his time become preferably from donkeys. Ejiao is prepared as dry gelatin or mixed with powdered oyster shell or pollen into glue balls; it tastes sweet and slightly bitter. It is taken dissolved in hot water or wine, is made into snacks and bars, and is used to fix the reed membrane on a Chinese flute.