In 1888 Feng Lishan, a chef, moved from Shandong province to Beijing and started to sell quick-fried goat tripe in the street, for which he was given the name Baodu Feng (Quick-Fried Tripe Feng).

His son Feng Jinhe took over the business at the end of the reign of Emperor Guangxu (1875-1908) in the Qing Dynasty (1644-1911). According to Feng Fusheng, the fourth generation of the business, his grandfather Feng Jinhe, happened to know a prince who was in a street fight and they became friends.

The prince then introduced Feng Jinhe to the imperial kitchen and he became the goat tripe provider.

Feng Fusheng's father collected all the recipes of their business in written form, from the methodology to the ingredients of the special sauce, and passed this on to his sons. Ox tripe was added to their list when Feng Fusheng and his brothers registered their brand name as a restaurant in 1985, and now they have 13 different types of tripe available with nine sheep cuts and four ox cuts.

Feng Fusheng says different parts of the tripe have different flavors and need separate time to cook.

"They all just need seconds to quick fry, but each of them has its own time.

If you taste all the parts you should start with the chewy ones and then the crisp ones and finally the most tender ones. Even though some of them are chewy, they are easy to digest because tripe is the stomach of a sheep or an ox."

For some parts of the tripe, one plate needs to be cut from seven to eight sheep. In summer when sheep are slim it is hard to come by, which gave rise to the use of ox meat.

"There are also different ways of cutting different parts of the meat, meaning each piece of the tripe can be heated evenly," Feng says.

Because Feng Fusheng and his brothers have been dealing with tripe for decades, there is always something of a sheep odor about them.

"When I'm on a bus or go to the bank, people notice the smell and ask if I have just eaten mutton hotpot," Feng says.