Making the special Pu'er tea is an elaborate process of some 70 steps, compared with other Chinese tea categories — green, yellow, black and oolong. Li says when stirring the tea buds, how high he tosses them from and what kind of wood he chooses to burn to match the suitable level of heat the tea requires are all elements that can affect the final quality.

"To be a good maker of 'tribute Pu'er', one has to have gifts apart from persistence," Li says.

He established a training center in Pu'er city where about 10,000 people have taken part in tea courses. However, no more than 10 could make him smile, he says.

"It takes one at least eight to 10 years to learn the technique. I'm not worried that my skills will be replaced by machines," says Li when asked whether he is nervous about artificial intelligence.