I recently learned how to sensory evaluate China's top-end tipple and joined an assembly line to package booze bottles while exploring the country's "liquor river" in Guizhou province.

The Chishui River, which takes its name from its reddish color, in Renhuai city's Maotai town has long remained underdeveloped - serendipitously, it turns out. The dearth of other industries has safeguarded the water's purity.

Indeed, the Yangtze tributary's superb quality is hailed as the magical ingredient that conjures China's most-famous firewater.