"The idea is that today you have this taste, and tomorrow, next week, or next month, you will enjoy exactly the same taste."

Ma recalls that when his restaurant was small there was a customer who lived in the United States and often visited Beijing.

"The first place he would come to after arriving in Beijing was my restaurant, and he would order 150 grams of braised mutton and a bowl of noodles with braised mutton, and as he was heading back to the States he would come to my place and have exactly the same order before going to the airport."

Ma has lived in Niujie all his life, as has Wei Ning, also known as Cheese Wei. Unlike Ma, he still owns a cheese shop in Niujie, but he is confronted by the problem that his sons show no desire to continue the business.

Wei started to help his father to make cheese when he was 31, before which he worked in a factory. Learning from making rice wines to make the cheese, Wei gradually understood what his family business was about.

"There's a duty and responsibility to maintain the family tradition," Wei says.

Both sons are in their 30s, one a police officer and the other a computer programmer, and Wei believes they will eventually realize that they have a duty to take over the business.

"I'm the fourth generation of our family business, and this should continue. My sons don't realize how precious this brand is."