Zheng Jianjun makes a guang bing. [Photo/WeChat account: npfjsen]

Since taking over the family business in 2006, Zheng has been experimenting with fermentation techniques to improve the taste of his creations. That same year, he registered the trademark "Wangdi".

In 2015, Zheng invested in a liquid nitrogen-based cooling technology developed by a research team in Fuzhou University, which allowed him to sell frozen versions that could be stored for much longer. Traditional guang bing need to be consumed soon after they are made.

Today, Zheng has opened seven chain stores in places like Yanping, Wuyishan, Shaowu, Shaxian and hires more than 50 employees. His company's annual guang bing output currently stands at more than 3 million pieces with a value of over 3 million yuan.

Zheng Jianjun (second from left) poses for a photo with customers. [Photo/WeChat account: npfjsen]