This is the very first monograph on tea making in Chinese history. It was written by Zhang Youxin, also called Zhang Kongzhao, a native of Luze of Shenzhou (present-day Shenzhou of Hebei) and a tea taster in the Tang Dynasty (618 - 907). Zhang became the first candidate in the highest imperial examination in the ninth year during the reign of Yuan He in the Tang Dynasty (814). He later served as governor of Jiangzhou and a minister. Zhang was good at writing and tea tasting. He was an expert in tea making. In about 825, he wrote the Report on Water for Tea Cooking. However, the contents of the book also suggested that it could be a work jointly by Lu Yu, Liu Bochu and Zhang Youxin.