Fig. 3

The picture derived from Chen [23] showed the classic of tea. This book was completed by Lu Yu (733–804) around CE 760. It not only introduces the history and geography of the tea plant, but also provides careful notes on the way to grow the tea plant, process tea leaves, brew, and serve tea. More importantly, the book helps to establish tea as a respected beverage and legitimize tea drinking as a cultural and elegant activity suitable for the elites