What Makes an Oolong so Oolong?

I love oolong teas. I love the mystery, the craftsmanship, the uniqueness and the wonderful complexity of an oolong. I love how the processing is so complex and painstakingly precise, yet it is still true to the inherent quality of the leaf. Before I start writing poetry and love letters about oolongs let me explain why oolongs are the best.

First off, what is an oolong? Oolongs are semi-oxidized teas. Green teas are not oxidized (ideally), black teas are “fully” oxidized and oolongs, generally speaking, are anything in between. It is not just the amount of oxidation that sets oolongs apart, but the plant cultivar, the firing process, the oxidation method and region. I still believe that true oolongs can only come from China or Taiwan.


Little information is available in the US about such an important factor in the crafting of an oolong. I guess this is not surprising considering the average quality of tea and the fact that we don’t grow any (commercially). The cultivar used to make a certain tea is at least equally important to the flavor of a tea as any other of the many factors that compose a tea. A lot of oolongs are made from cultivars that are used only for oolongs, some that do not grow outside of the region they are specific to. Da Hong Pao, Ti Kwan Yin, Shuixian, Maoxi, Fenghuang Danchong are some of the more famous oolong cultivars used in China. Taiwan numbers their cultivars 1-18, 18 being the most recent development used to make the only black tea produced in Taiwan. The first cultivar ever to be planted in Taiwan was a Wuyi cultivar said to have been Ti Kwan Yin. Each cultivar of course tastes different and is usually processed differently according to how the tea maker believes it should be done. For example, oxidizing certain cultivars darker or lighter can make a tea change from a light floral fruity taste to a tar like musty leather taste with darker fruit. The type of cultivar used to make a tea provides the base taste of the tea. In other words all of the flavor is in the tea leaf, it just needs to be brought out in the right way.


Oxidation is the most plainly obvious difference between oolongs and other kinds of tea. The amount of oxidation varies from very light (10-15%) such as a baozhong, to almost as dark as black tea, such as Bai Hao or Wuyi Yancha. Traditionally made Ti Kwan Yin is oxidized a bit heavier at 20-30. Baozhong is so light that it is sometimes put in a different category. Bai Hao is usually darker and more evenly oxidized than most Darjeeling first flush which is considered a black tea. Often, most semi-ball type oolongs that are dark in leaf color have a light oxidation with a heavier roast that makes them darker in appearance and taste. The techniques that are used to achieve a certain level of oxidation vary quite a bit and are often very labor-intensive. Repeated rolling, withering and firing are often involved. The oxidation for some Phoenix Mountain oolongs is very interesting, creating a final product where the leaf is almost half olive green and half brown. Technically this should be a flaw and this is evident in the taste. It creates an extremely fruity but also a hollow, soapy bitter taste that is unique to Phoenix Mountain. If you find a phoenix mountain that is not bitter yet also very fruity and sweet, you have found an excellent tea.

Oolongs are either pan-fired or roasted. Firing or roasting an oolong too much is the best way to ruin a good oolong. On the other hand, it is the best way to make an oolong of poor quality better. The roasting process is slow and done at very low temperatures. It seems that with Taiwan Oolongs, the ideal flavor from a roast is a sweet cinnamon flavor present in the rinse and first steeping. Often it will taste more like roasted grain and when roasted too dark, smoke and sour dough bread are also present.

Region is another character that makes oolongs unique. The region provides the base for growing these wonderful teas and in some cases the climate and soil is so unique that certain cultivars will not grow outside them. Oolong tea is really only grown and processed in southeastern China and Taiwan. Taiwan has many micro regions that produce fantastic oolong and all are unique to one another. Li San, San Lin Shi, Ali San, and Wen San are some of the more famous mountains and quality producers of oolong. In China, the Fujian and Guangdong provinces produce most of the Chinese oolong and are grouped with Hainan and Guangxi as the South China region. Fujian is home to Wuyi and Anxi, the most famous micro regions that produce oolong. Guangdong is home to Pheonix Mountain which produces a oolong like no other. India is producing a very small amount of oolong but it is usually processed incorrectly and of commodity quality.