Production is complicated, with one of the main ingredients being fish, preferably silver carp. Each one weighs around 1.5 kilograms.
Another main ingredient is fatty pork, which distinguishes Chang'an yanqiu from ordinary fish balls.
"Adding fatty pork makes it more fragrant and gives it a richer and more substantial taste," Xie explains.
After the meatball is fashioned by hand out of mashed fish and pork, it is rolled over shredded pork skin, which will stick to and wrap the outside of the meatball.
"It is then crispy on the outside and soft in the middle, providing a rich mouthfeel," Xie says.
To his surprise, the first 28 yanqiu meatballs he made using three fish drew the attention of villagers he met on the way to the local central food market, and they sold out before he even got there.
It gave Xie a glimpse of the potential business opportunity, and thus encouraged him to run with his idea of selling yanqiu.
"In the beginning, I just sold it during major holidays, but business started to take off, with many placing orders ahead of time," Xie says.
It prompted him to set up a stand at the central food market.
In fact, Xie's move was so groundbreaking that he struggled to get a sales license.
"Yanqiu didn't really belong to the deli or the non-deli sections that were all there were then," he says.
After he got things straightened out, people couldn't get enough, with 2,000 yanqiu being sold on a good business day.
As Xie started to make a name for himself, he had customers who came all the way from other cities to buy his yanqiu.
Tan realized the business potential after seeing his father-in-law doing so well.
He says he was impressed by his yanqiu the first time he visited him.
"My father-in-law was one heck of a cook, and people obviously loved the yanqiu he made. More importantly, people's financial situations were improving," Tan says, explaining the signs he recognized that led to him scaling up the business.
Tan had developed a certain business acumen by selling clothes and realized that a lot needed to be upgraded before it would be possible to industrialize yanqiu production.
"The fish meat was inconsistently chopped, and the ingredients were added based on experience, leading to inconsistency in the flavor," Tan says.
After inheriting the traditional method of making yanqiu, in 2007, Tan knuckled down to the business of building a factory, investing more than 400,000 yuan ($55,272) into the project.
"The money back then could have bought a three-story building in our area, and many relatives and friends didn't understand the decision, asking me how many yanqiu we would have to sell just to break even," Tan recalls.