It’s all in the leaf
Tea is grown in thousands of tea gardens and estates around the world, resulting in thousands of flavorful variations. There are some teas, like wines, that take their names from the district in which they are grown. Other teas are divided by grades, which are determined by the size of the leaf. Typically, smaller sized leaves are used in tea bags and larger sized leaves are used for loose tea.
All tea that is not herbal or tisane, comes from the plant species, Camellia sinensis. Herbals and tisanes are an infusion of leaves, roots, bark, seeds or flowers of other plants. While many herbals and tisanes have medicinal qualities and other benefits, they do not have many of the characteristics of tea.
There are five types of tea, White, Green, Oolong, Black (also known as Red in some Asian cultures) and Pu-erh. The method of processing the tea plant and their level of contact with oxygen determine the different types of tea. During oxidation, tea leaves undergo natural chemical reactions that result in distinctive color and taste characteristics.
Green teas are not oxidized, rather the leaves are steamed and rolled. White teas are only slightly oxidized. Both white and green teas most closely resemble the look and chemical composition of the fresh tea leaf. Black tea typically oxidizes for two to four hours and oolong tea falls somewhere between green and black teas, in that the leaves are only partially oxidized.
Pu-erh tea derives its name from the ancient market town, within Yunnan province, where it originally came from and is the only tea that is truly fermented and aged. Pu-erh is produced in almost every county and prefecture in the province, but the most legendary pu-erh areas are known as the Six Famous Tea Mountains. Liu Bao, a tea that originates from Liubao in the Guangxi province of China, is often categorized with pu-erhs as it is processed in much the same way.