Han Yun selects soybeans at his workshop, March 28, 2016. [Photo/VCG]

Han Yun, 61, and his son Han Tianlong, 29, own a small oil mill in Changchun, capital city of Northeast China's Jilin province. Because of their excellent oil extraction technique and the product's unique favor, they have many customers.

They opened the workshop 10 years ago and expanded it in 2012. More than 250 kilograms of oil can be produced every day, Han Tianlong said. To improve production efficiency and reduce costs, his father also invented some machines by himself.

"I not only learned the traditional oil extraction technique from my father, but also learned marketing on my own, which can ensure that this craftsmanship can be continued", Han said.