Longjing tea is actually not from Hangzhou. Many of these "inauthentic" longjing teas are produced in provinces such as Yunnan, Guizhou, Sichuan, and Guangdong. However credible sellers may sometimes provide anti-fake labels or openly state that the tea is not from Zhejiang. Experienced drinkers may be able to tell if Longjing is authentic by taste and smell. The aroma and flavors of the "inauthentic" Longjing teas are not as complex, or long-lasting as the authentic tea. These teas, although similar in appearance, are mild in flavor and aroma and do not have the long-lasting aftertaste of the original. Longjing has a signature
Wuyi tea technique for stopping the oxidation process of tea, pan-firing the leaves in a dry wok rather than steaming them as had been done previously. Songluo-style green tea became popular, and the new production method spread to other regions. In the 16th century, Wuyi tea makers invited monks from Songluo to teach their techniques to them. Eventually they discovered that by allowing the tea to partially oxidize before firing, they could produce a darker, fragrant type of tea which came to be known as oolong ("wulong", "black dragon") tea. European merchants began purchasing tea in Canton (Guangzhou) during the 17th century.