In our previous article, we knew that teas are derived from the Camellia sinensis plant. What categorizes them into green, white, oolong, pu’erh and black teas is the process the leaves undergo. Native to Asia, tea is now planted and harvested around the world.
Tea is categorized under 5 basic types; green, black, white, oolong and pu’erh. Any leaf, fruit, flower or root derived from a plant not native to Camellia sinensis is classified as herbal tea. Rooibos teas belong to the legume family.
The distinction in tea type results from the oxidation process that each tea undergoes. Oxidation is not fermentation. Exposing tea leaves to air, forces leaves to oxidize. The oxidation process develops both flavor profile, and darkening in leaf color. Oxidation occurs immediately after leaves have been plucked. Tea leaves are rolled by hand or machine to crack the leaf, and accelerate this process.
Green teas are withered slightly after being picked. The oxidation process is halted by applying heat to leaves (via steam or pan firing). Heat seals, and prevents oxidation to occur in teas through a chemical process. Green teas are lightly heated, and retain most of its natural colors. Minimal processing of teas, make green teas more subtle and delicate in flavor. They are best steeped at lower temperatures to help retain its light flavor profile.
Black teas are withered longer than other types of tea. Withering allows water to evaporate from the leaf, and allows the leaf to oxidize quicker. As teas oxidize, the leaves darken in color. The longer oxidation period gives black teas higher concentrations of caffeine, with a bolder astringent taste. Black teas are the most common base for iced teas.
White teas are processed the least among varying tea types. They are handpicked, and consist of the best buds found on the plant. White tea are named for the white hairs found on the buds picked. Due to minimal processing, they are the extremely delicate. They are subtle, complex, and sweet in nature. White teas are not rolled or shaped like its peers. Steeping white teas require lower temperatures and shorter steeping times. White teas contain lower levels of caffeine compared to green and black teas.
Oolong teas undergo partial oxidation. Oolong teas generally require more time to process than other teas. Within the range of tea types, oolong sits in between green and black. Oolongs once plucked are withered, rolled for oxidation, and repeated. The repeated rolling process give oolong teas added layers of flavors giving oolong a complex profile. Oolong teas contain caffeine that is greater than green, but less than black. Oolongs flavor tones are more robust than green teas, but less than blacks.
Pu’erh teas are aged tea leaves. Pu’erh teas are withered, and pressed into dense shapes (referred to as cake). Pu’erh teas are fermented, and aged for months to years. The processing of pu’erh is not openly disclosed as methods vary and kept secret. Pu’erh teas are earthy in flavor profile with no bitterness, and extremely expensive.