A worker checks the quality of vinegar in Chishui, southwest China's Guizhou Province, June 26, 2020. Chishui has been famous for its sun vinegar, which has maintained a traditional making process. The production techniques of the Chishui vinegar, featuring the sunning process, was listed as a provincial intangible cultural heritage of Guizhou in 2009.Photo:Xinhua

Dong Bin, head of a vinegar making plant, tastes vinegar to check the quality of it in Chishui, southwest China's Guizhou Province, June 26, 2020. Chishui has been famous for its sun vinegar, which has maintained a traditional making process. The production techniques of the Chishui vinegar, featuring the sunning process, was listed as a provincial intangible cultural heritage of Guizhou in 2009.Photo:Xinhua

Workers package vinegar in Chishui, southwest China's Guizhou Province, June 26, 2020. Chishui has been famous for its sun vinegar, which has maintained a traditional making process. The production techniques of the Chishui vinegar, featuring the sunning process, was listed as a provincial intangible cultural heritage of Guizhou in 2009.Photo:Xinhua

Aerial photo taken on June 26, 2020 shows a worker checking the quality of vinegar in Chishui, southwest China's Guizhou Province. Chishui has been famous for its sun vinegar, which has maintained a traditional making process. The production techniques of the Chishui vinegar, featuring the sunning process, was listed as a provincial intangible cultural heritage of Guizhou in 2009.Photo:Xinhua

Workers carry brewing mass at a vinegar making plant in Chishui, southwest China's Guizhou Province, June 26, 2020. Chishui has been famous for its sun vinegar, which has maintained a traditional making process. The production techniques of the Chishui vinegar, featuring the sunning process, was listed as a provincial intangible cultural heritage of Guizhou in 2009. Photo:Xinhua

A worker checks the quality of vinegar in Chishui, southwest China's Guizhou Province, June 26, 2020. Chishui has been famous for its sun vinegar, which has maintained a traditional making process. The production techniques of the Chishui vinegar, featuring the sunning process, was listed as a provincial intangible cultural heritage of Guizhou in 2009.Photo:Xinhua