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What exactly is "Oolong"? A kind of tea? A cultivar? Or a product name?

The short answer is: it's all of the above. However, examining this question will help us gain a better understanding of how dynamic and young the world of oolong tea is.

Oolong leaves on a tea scoop

Here's the thing. The black tea you bought from a tea vendor may be made from "oolong" leaves, while your Taiwanese friend might say that the "Dong Ding Oolong" you brought from Taiwan is not from Dong Ding and isn't an "Oolong" but a "Jinxuan." And if you disagree, you both might be right.

So you mean to say they've taken what we thought we think and make us think we thought our thoughts we've been thinking our thoughts we think we thought?

"Oolong" most commonly means partially oxidized tea

By far, the most common way "oolong" is used as a term is to describe one of the six categories of tea (according to the ISO 20715:2023 classification of tea). It stands for partially-oxidized tea, just like "black tea" refers to fully oxidized tea. Taiwan's Muzha Tieguanyin, Oriental Beauty and Wenshan Baozhong, as well as China's Wuyi Mountain Dahongpao, Phoenix Mountain Honey Orchid and Anxi Golden Water Turtle among others are all considered oolong teas.

A little side note from myself as to why we don't call oolong "semi-oxidized" or use the word "fermented." "Partially oxidized" implies that parts of the tea leaf are oxidized, while other parts aren't. "Semi-oxidized" implies that the whole leaf is oxidized, but not to the full extent. The former is more accurate when describing what is happening to oolong leaves. As to the difference between "fermented" and "oxidized," fermented refers to the process of chemical change because of the action of yeast or bacteria, whereas oxidation occurs when the tea leaves are exposed to air. The most common fermented teas are dark teas (heicha) and shu pu'er.

"Oolong" can mean a cultivar

Yep, you can make green tea, white tea, or black tea from "oolong." But how does that work?In Taiwan and China, some cultivars (also known as varietals) have the word "oolong" in their name. For example: "Big Leaf Oolong" (大葉烏龍) or "Red Bone Oolong" (紅骨烏龍). Since Taiwan specializes in oolong production, most cultivar names are derived from the varietals that already had "oolong" in their name and as such are also considered "oolong" cultivars, even though the word itself is no longer mentioned in their names: "Green Heart" (青心), "Four Seasons Spring" (四季春)、"Jinxuan" (金萱).

In Dongding, tea farmers call Green Heart (Qingxin) Oolong "oolong" or "soft branch"; in Pinglin, tea farmers call Qingxin Oolong "Zhongzai" which can be translated as "breed" or "cultivar". It can also be called "Zhongziqi" which has a similar meaning as a "flagship cultivar." And no wonder, since at present, Taiwan's emerging high mountain tea areas are almost exclusively dominated by Qingxin. Oolong tea made from Qingxin Oolong species has a special aroma similar to that of orchid and osmanthus.

"Oolong" can be used as a product name

Now, this one might sound odd to people outside of Taiwan. After all, the name under which the Western consumer got to know Taiwanese oolong was "Formosa tea." The product with the name "oolong" that the Taiwanese public was most familiar with at the time was "Dong Ding Oolong".

The origin of the name comes from Zhangya Village, Nantou, on the Dong Ding plateau (translated as "Frozen Summit") about 700 meters above sea level. It is famous for producing partially-oxidized tea that has different characteristics from the light-flavored Wenshan Baozhong. Hence the saying "Baozhong in the north, oolong in the south." Dong Ding Oolong has a higher degree of oxidation and a much heavier roasting. This roasted flavor was all the buzz in Taiwan during the early years of tea production, and as Dong Ding Oolong grew so popular, other regions also began to imitate and make tea with the same flavor. Today, we can see "Dong Ding Oolong" made from Qingxin, Jinxuan, or Jade Oolong cultivars coming from the nearby regions.

The same situation also occurs in the definition of the term "Tieguanyin". In Taiwan, Tieguanyin originally refers to the Tieguanyin cultivar and Tieguanyin processing style of the Muzha mountains. The charcoal-roasted tea with a strong fire aroma is what's known as Tieguanyin. However, because it was very popular in the market, some people started making tea using different cultivars such as Jinxuan while still calling it Tieguanyin. But that was back in the 20th century. Since then, Taiwan has experienced a shift in taste, preferring much lighter, floral, and fresh tea. Because of this change, most "Tieguanyin" on the market now has lower oxidation and much less roasting/baking. "Muzha Tieguanyin" is now used to specifically refer to that older, more traditional method of production. However, in the Muzha area, 正從鐵觀音, translated as "Proper Tieguanyin" still refers to both the traditional Tieguanyin processing style and the Tieguanyin cultivar.

The high mountain oolongs I've mentioned before are a newer trend in Taiwan (albeit not as new as the red oolong and honey flavor tea). Oolong teas from high mountain production areas such as "Alishan High Mountain Oolong", "Lishan High Mountain Oolong" or "Shanlinxi High Mountain Oolong" all use the name of the region + "oolong" in their marketing. Since "high mountain oolong" is the product name, any tea leaves can be used for the tea. This emphasizes the terroir rather than the cultivar when marketing to the customers.

Bringing it all together

We hope we were able to shed some light on this confusing topic. Consumer preferences shift, and while some teas rise in popularity, others fade into obscurity. If you can systematically identify the qualities of tea and understand the scientific principles behind these qualities, you will easily choose the right teas for your taste. We will address this systematic approach in our next article. For now, we wish you happy tea drinking.


Source:《烏龍茶的世界by Chen Huantang, Lin Shiwei


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