Oolong tea is renowned for its unique and rich aroma. Some may wonder if the fragrance in Oolong tea comes from artificial flavors. No, the distinctive aroma of Oolong tea is determined by various factors such as the tea tree variety, the standards for picking fresh leaves, and the manufacturing process.
Tea Tree Variety
1."Varietal Aroma" of Oolong Tea
The differences in fresh leaves and growth characteristics of different tea tree varieties determine the unique aromatic quality of loose leaf oolong tea. Many famous Oolong teas are often named after the tea tree variety due to their distinct aroma.
The "Varietal Aroma" of Oolong tea is quite prominent. For example, Da Hong Pao has a "rocky charm," Tie Guan Yin has a "musical charm," and Rou Gui has a "cinnamon fragrance." Oolong teas with "Varietal Aroma" are often considered classic and make excellent Christmas tea gifts or New Year tea gifts.
2.Characteristics of Oolong Tea Tree Varieties
Most Oolong tea tree varieties have medium to large-sized leaves with a thick waxy layer on the leaf surface. During processing, this wax can transform into aromatic substances, contributing to the fragrance of Oolong tea.
In addition to large-leaf Oolong varieties, the lower epidermis of tea tree leaves contains glandular scales that can also secrete aromatic substances, adding another dimension to the aroma of Oolong tea.
Furthermore, mature leaves contain lipid particles that are absent in the tender shoots of a single bud and leaf, providing a material basis for the formation of a rich aroma during the initial processing of Oolong tea.
Fresh Leaf Standards
1.Oolong Tea Fresh Leaves Require a Certain Level of Maturity.
The quality of fresh leaves directly affects the overall quality of Oolong tea.
The requirements for fresh leaves in loose-leaf Oolong tea differ from those of loose leaf green tea. Oolong tea requires a certain level of maturity, and the picking process involves "open-faced picking." When the leaves are in the "open-faced" state, the content of aromatic components such as benzaldehyde and linalool is higher. Additionally, it contains more amino acids, carotenoids, and other compounds.
2.Oolong Tea Fresh Leaves Should Not Be Too Tender or Too Old.
The withering and oxidation processes contribute to the formation of aldehyde compounds, enhancing the aroma of Oolong tea. If the fresh leaves are too tender, the content of catechins and caffeine in the leaves will be excessively high. The precursor substances of aromatic compounds, such as sugars and ether extracts, will be relatively low, resulting in a tea with a lower aroma and a bitter taste that does not meet the quality requirements of Oolong tea.
Of course, the fresh leaf material should not be too old either. Tea made from overly mature leaves will have a coarse appearance, lack internal substances, have a lower quality due to low aromatic compound levels, and higher cellulose content, making it challenging to achieve the desired high aroma and mellow taste characteristic of Oolong tea.
Tea Processing Technique
Zuoqing is a characteristic process in Oolong tea production, and it is a key step in shaping the quality style of Oolong tea that other loose leaf tea do not undergo. The unique aroma of Oolong tea is also developed during this process. Therefore, tea farmers often say they are "turning the river and overturning the sea to produce Oolong." Withering involves two steps: Yaoqing (shaking) and Liangqing (cooling), which are performed alternately.
Yaoqing (shaking) : Simply put, it involves continuously shaking the withered tea leaves in a bamboo sieve. The tea leaves dance and roll inside the sieve, causing friction and collision between the leaves and the sieve walls, as well as between the leaves themselves.
Liangqing (cooling) : After Yaoqing (shaking), the tea leaves are spread thinly on a bamboo sieve and left to rest for a period.
The purposes of these operations are twofold. First, to damage the cell walls, increase the ratio of tea extracts within the leaves and stems, and enhance the tea's aroma. Second, to induce a slight fermentation in the tea leaves, creating a complex aroma. Without the alternating Yaoqing (shaking) and Liangqing (cooling) process performed three to five times, it is challenging for Oolong tea to develop a strong aroma while possessing various floral and fruity qualities. It is precisely this intricate and complex withering process that allows many classic Oolong teas, such as Tie Guanyin, Da Hong Pao, and Fenghuang Dancong, to be considered among the best loose leaf tea varieties.
Compared to the roasting of green tea, the roasting of Oolong tea serves not only to dry and halt the oxidation of the raw tea leaves but also involves further processing of the leaves.
The roasting of Oolong tea is also known as "baking." It involves roasting the tea leaves to control fermentation by altering the moisture content within the leaves. This process also leads to the transformation of substances such as catechins and caffeine, ultimately adjusting and controlling the final aroma of the tea. This is the fundamental principle behind the roasting of Oolong tea.
During this process, the degree of roasting varies, influencing the final aroma. For lightly roasted Oolong teas, such as TieGuanyin, there is a delicate and clear flavor. For moderately roasted ones, like Da Hong Pao, there is an initial presence of "fire aroma," which may dissipate after some time or multiple infusions. Only then can one experience the high aroma, sweetness, and various floral and fruity notes characteristic of Oolong tea. To appreciate the differences in roasting levels of Oolong tea, one can try comparing tea samplers, allowing for a better understanding of the nuances and delights involved.
It is the unique tea tree varieties, specific picking standards, and exquisite craftsmanship of Oolong tea that contribute to its distinctive and rich aroma, including notes of freshness, floral, fruity, honey, and floral-fruit fragrances. Hopefully, this article will help readers gain a deeper understanding of Oolong tea, enabling them to better savor and appreciate this unique loose-leaf tea.