In 2010, the yanqiu craft was named an intangible cultural heritage in Jiaxing city.
Although Chang'an yanqiu has a long-established reputation, local families used to make it only for special occasions.
"It was too troublesome to make, and to have both fish and pork was expensive. Ordinary families couldn't afford it," says Tan, who is in his 40s.
After careful preparation, only 30 percent of a fish can be used to make yanqiu, he says.
While the general recipe has been passed down among families, and the ingredients have mostly remained the same, each family has come up with its own preparation method.
Yet, for centuries, no one thought to sell yanqiu at the market.
Tan says that the commercial popularization of the local specialty started with Xie Yifei, his father-in-law, when the latter tried to sell the product to fellow villagers in the 1990s.
"It was on a whim," says the 70-year-old Xie, who was a professional carpenter, and who picked up the yanqiu craft from his father.