Tea, the most popular beverage consumed by two-thirds of the world’s population is made from the processed leaf of Camellia sinensis. Tea types, based on processing or harvested leaf development are black (fermented), green (non-fermented) and oolong (semi-fermented). These major tea types differ in how tea is produced and processed according to the different processes of drying and fermentation that determine its chemical composition. Green tea is produced by using young tea leaves and sold for consumption without fermentation after withering, steaming or pan firing, drying and grading. Pan firing is required to prevent the tea leaves from fermenting by the natural enzyme activities. Tea leaves are allowed to ferment for several hours before being either smoke fired, flame fired or steamed to make black tea. Oolong tea is produced by a partial oxidation of the leaf, intermediate between the process for green and black tea.