Introduction:When tea leaves are first picked, they carry a grassy bitterness. The truly captivating aromas are only brought out through professional tea processing. Among these steps, withering—being both foundational and critical—directly influences the final color, aroma, and flavor of the tea. This article delves into how different types of tea regulate withering duration and conditions, especially why Darjeeling spring tea and oolong tea share similar floral-fruity notes and hues, uncovering the science and craftsmanship behind it.
Right after being harvested, tea leaves are rich in compounds that have not yet transformed, often resulting in a bitter, grass-like taste upon tasting. These flavor compounds originally serve as the plant’s natural defense against external threats. Once the leaves are plucked from the tea plant, the first major change is the loss of supply from the roots, leading to dehydration. Meanwhile, internal substances undergo a series of transformations: starch gradually converts into glucose, proteins break down into amino acids, and fatty acids degrade into various aromatic compounds.
This process, known in the industry as “withering” or “dehydration,” is a key step that determines the direction of the tea’s aroma. Different withering durations directly shape the aromatic profile of the finished tea. For example, green tea, which aims for a fresh and brisk taste, undergoes extremely short withering, just enough to produce small amounts of fragrant compounds like linalool and hexanol with citrus-like notes. In contrast, oolong tea and black tea require longer withering times to unlock more complex layers of aroma.
Notably, CTC black tea from Assam is often considered to have relatively weak aroma, one of the main reasons being its insufficient withering stage. Coupled with the region’s tropical climate, which results in very high humidity, the tea leaves struggle to dehydrate effectively, further limiting aroma development and substance transformation.
On the other hand, in the production of high-mountain oolong, Darjeeling spring-picked tea, and certain high-altitude Ceylon black teas, tea makers deliberately extend the withering time—sometimes even by several hours longer than usual. This treatment not only helps the internal moisture evaporate evenly, promoting aroma concentration, but also allows the internal components of the tea leaves to become more concentrated, thereby enhancing overall flavor performance.
During prolonged withering, fatty acids continue to break down, producing aromatic compounds such as geraniol with its geranium-like scent and methyl jasmonate that emits a jasmine aroma. Additionally, the formation of methyl salicylate contributes to the unique minty note found in some origins, such as Ceylon black tea from the Uva Highlands, becoming one of its signature flavor characteristics. At the same time, carotenoids in black tea and some darker oolongs gradually decompose and transform into aromatic substances like ionone and damascenone, lending the tea liquor sweet fruity notes reminiscent of apricots, peaches, and honey.
In fact, well-withered tea leaves already emit an enchanting fragrance even before brewing. Stepping into a tea factory during the harvest season, the air is filled with natural scents of lemon, jasmine, and apricot, as if entering a professional perfumer’s blending lab. This fresh, floral-fruity aroma is often something that cannot be fully replicated in the brewed tea liquor and is a direct reflection of the precision and finesse in tea-making craftsmanship.
For tea enthusiasts who enjoy exploring the nuances of tea flavors, understanding the differences in withering techniques not only helps distinguish the characteristics of various tea types, but also allows for a deeper appreciation of the craftsmanship and natural transformations behind each cup.
The above content is compiled by CoffeeHunters, a coffee news website.
