Oolong is the most labor intensive of the types of tea, and the most highly prized oolongs are processed only by very experienced tea masters. Oolong tea is a huge topic because of the many different styles that are produced. The specific varietals of the Camellia Sinensis (tea plant) used in traditional oolong teas come from Fujian and Guangdong provinces in mainland China, but these oolong varietals are cultivated in many other parts of the world today. The general consensus is that the best oolongs come from Fujian and Guangdong on the mainland, and also from Taiwan, where oolong teas are somewhat of a regional obsession. From a processing standpoint oolongs are somewhere between green and black teas. They are picked and withered about like green teas, but the firing step is delayed until later. After withering, the tea leaves are rolled or shaken to bruise the edges of the leaves and to release some of the enzymes in the leaves. The release of the enzymes starts the oxidation process. When these enzymes are exposed to oxygen they begin to turn brown in color, much like when an apple is cut open and the flesh begins to turn brown when exposed to the air. This process of oxidation in oolongs is what really brings out their unique flavors and requires the experience of the tea masters to judge when the teas are actually ready. A complex process of further rolling or shaking along with slow and low temperature drying steps takes place until the tea master decides that the tea has oxidized to the point that he or she deems appropriate to the style being produced. Once the desired oxidation level is achieved, the tea is then fired to stop the tea from oxidizing further. Then it is completely dried and in some cases is ready for consumption. The number of oolong tea styles is huge because of the many variables used in processing. They can be very green in color or look almost like a black tea. They can be very tightly rolled little balls or long twisty stripe shaped leaves. The level of roasting that the teas receive after processing greatly influences the flavors achieved in production. Typically, oolong teas are very complex in flavor and can have an amazing floral sweetness in the flavor with a very pleasant lingering aftertaste. Many tea masters will age a portion of their teas, and aged oolongs are some of the most prized and hardest to find teas around. Aging oolongs is very different from aging pu-erh teas because the oolongs are kept in tightly sealed jars and are low temperature roasted periodically to drive out any moisture that accumulates in the leaves.

Black tea is the type of tea that people in the west are most familiar with. Black teas are fully oxidized teas, meaning that the enzymes in the tea leaves turn the leaves completely brown during the processing. The teas are picked and withered like the other types of tea. Then they are either hand rolled or machine rolled to crush all of the cell walls in the leaves and release the enzymes that promote oxidation. The teas are then left to oxidize completely or to turn brownish black in color. Once the leaves have completely oxidized, they are then roasted to deactivate the enzymes and to dry the leaves. Properly handled black teas can be kept fresh for about two years after harvest without losing much quality, which is why black tea became popular in the west. It could withstand the long journey from China and later India and Sri Lanka without a discernable loss of quality, while green teas could not. Black teas are produced in many parts of the world today, most notably in India, Sri Lanka, parts of Africa, and South America. Most of the production is done by machine using the British developed "CTC" method or Crush, Tear, Curl, which yields a very consistent and finely chopped end product that looks a bit like coarsely ground coffee. CTC teas are commonly found in teabags under various brand names. The highest quality black teas are not CTC teas (though some CTC teas can be excellent), but are referred to as orthodox teas, meaning that the leaf structures (and more of the desirable complex flavors) are preserved during production. High quality black teas like the highly sought after teas from the Darjeeling region of India are almost always produced in the orthodox fashion.