Longjing tea from bluish to deep green after steeping. Before infusion, higher quality Longjing teas have a very tight, flat shape and light green color. A study by Wang and Ruan (2009) found that one aspect of the perceived low quality of Longjing teas was a higher concentration of chlorophyll, producing a darker green color. The study revealed that free amino acids and theanine concentrations contribute positively to what is perceived as a good taste. Longjing tea was granted the status of Gong Cha, or imperial tea, in the Qing dynasty by the Kangxi Emperor. According to the legend, The Kangxi Emperor's
Chinese tea and the production is regulated by the Chinese government. Some, however, consider its taste to be second to Tianchi tea (; lit. "Heaven Pool"). Jie tea from Changxing County in Zhejiang Province is regarded highly by connoisseurs, although it is rather expensive. NB: "Jie" is the short name for "Luo Jie" (). Luo Jie is the name of a mountain bordering Zhejiang and Jing Qi where, during the Ming dynasty, "jie" meant boundary. Chang Xin lay to the south of Luo Jie mountain while Jing Qi lay to the north of it. Chang Xin still retains its name today. Luo