Who knows the origin of Bagongshan tofu?

Tofu originated in Shouxian County, Anhui Province, with a history of more than 2,000 years. The best quality tofu is called "Bagongshan Tofu" in Bagongshan, Shouxian County. This kind of bean curd is made of pure soybean and refined by adding spring water from Bagong Mountain. The skills of local farmers in making tofu have been passed down from generation to generation. Many people have mastered a set of good skills, and the tofu made is fine, white, fresh and tender, which is well received by the masses. According to Li Shizhen's Compendium of Materia Medica, a famous medical scientist in the Ming Dynasty, "The method of tofu began with Liu An, the king of Huainan." In Qing Dynasty, Wang Ji said that "everything must be the same": There is a record in the ancient books of the Western Han Dynasty that "Liu An made tofu". Liu An, the grandson of Emperor Gaozu Liu Bang, whose capital is Shouchun (now Shouxian), has attracted thousands of guests and alchemists, among whom Su Fei, Li Shang, Tian You, Jin Chang, Mao Bei and Zuo Wu are famous. Liu An, often accompanied by Hachi, tried to make a panacea for immortality. He doesn't want to make an alchemist, but uses soybeans and brine (or gypsum) to make tofu. There is another legend about Bagongshan tofu: Liu An couldn't make an alchemy at home, so he kept it in his chest and went out for fun. Suddenly, he saw eight old people coming down from the opposite Beishan. Although they must be chest-high, they are full of energy and legs. Liu An was frightened and doubted that he was a fairy, so he asked him for the prescription of immortality. The old man said that he had eaten food made of ground soybeans. Liu An did the same thing and got tofu. Since then, the method of tofu has spread from the foot of Bagong Mountain. What are the characteristics of Bagongshan tofu? Bagongshan Tofu began in the Western Han Dynasty when Liu An, king of Huainan, and other eight ministers in government and opposition were dismissed here. Originally, I wanted to make tofu by alchemy, so I got the name because of its tender quality and delicious taste. Because it is refined from Bagongshan spring water, its finished product is crystal clear, white as jade, tender and smooth, delicate in texture, without yellow paste and water smell, and its support is unbreakable, so it is famous throughout the ages and has a long reputation. Bagongshan tofu, also known as green tofu, is named because it can be cooked in all seasons.