Many people believe that the production of Puer Tea has a low threshold and lacks significant technical sophistication. Such views generally disparage the craftsmanship of Puer tea, but they also inadvertently highlight its natural origins. Since the regions where Puer tea is produced are mostly mountainous and lack the mechanized picking conditions found in southern China, during the Spring Tea season, all the villagers mobilize. The sight of tea farmers dressed in their ethnic attire picking fresh leaves on the mountains is a unique and stunning landscape in Yunnan's tea areas.

The high standards for leaf grading require picking of one bud with two or three leaves. After manual picking, to prevent oxidation, the tea leaves are placed in bamboo baskets or cloth bags carried by the pickers and transported to nearby processing facilities. Before sun-drying, the tea leaves are laid out to drain off excess water, and then they undergo the process of killing greenness (kill-green).

The kill-green and sun-drying processes are among the core steps that define Puer tea. The kill-green process is often referred to as the “life and death line” of Puer tea, emphasizing its critical importance. Traditionally, this was done using firewood and iron woks, with some seasoned Puer tea experts even suggesting that the term “Wok stir-frying” would be more accurate. Traditional equipment and techniques align better with the natural, human-made, handcrafted requirements of Puer tea. However, with the expansion of market demand and increased standardization, only a few niche brands, such as “Deep Forest,” still adhere to using firewood, having stored enough wood for a decade's worth of Puer tea production.

Considering ecological factors, energy efficiency, cost, and hygiene, the use of firewood for the kill-green process has gradually faded from mainstream use, being abandoned by major brands and some small workshops in favor of electrified methods or even the use of biofuels.

Regardless of the tools used, the primary purpose of the kill-green process remains to inhibit enzyme activity and slow down fermentation. During the kill-green process, the temperature in the wok is maintained above 200°C, while the surface temperature of the leaves is kept between 60°C and 80°C. High temperatures kill some active enzymes, slowing down the transformation of the tea. Despite this, due to the high moisture content in the fresh leaves, there remains sufficient active enzymes to facilitate the conversion of Puer tea. The kill-green process also matures the tea, reducing its raw flavor, softening it to make it easier to roll without breaking, and preserving its potential for further development. Seasoned Puer tea expert Chang Jinqiang once used the analogy of flour fermentation: after processing, the flour needs to ferment when used for steamed foods. If the flour has lost its vitality, it cannot provide the necessary microorganisms for fermentation.

After the kill-green process, the tea enters the sun-drying phase. This is the step that most vividly showcases the natural essence of Puer tea. During the spring tea season, rooftops, balconies, and drying sheds across the region are filled with tea laid out to dry, resembling large flatbreads. Row upon row of tea, either arranged in magnificent formations or scattered under the sun, undergoes sun-drying to absorb sunlight and dry thoroughly.

The success of making tea during the spring season depends on the weather. Tea farmers often work day and night, sweating profusely as they process tea, hoping for a sunny day. Baskets of tea leaves, after a full day of “sunbathing,” are nearly semi-finished products by sunset. People, tired from a day's work, can hardly contain their excitement as they scoop up a handful of tea, place it in a lidded bowl, and steep it to taste. At this point, the tea is fresh and clear, with a minty aroma, especially for teas like Bingdao and Mansong, which are rare treats.

Many tea enthusiasts who taste good Puer tea often praise it by saying, “This tea has the taste of the sun.” While the specific flavors may vary, they are certainly connected to the natural sun-drying process of Puer tea.

However, if the weather does not cooperate, the tea must still be processed. Typically, the tea leaves are spread out to prevent dampness, waiting for a sunny day to dry them properly or taking certain physical drying measures.

If improperly handled, the finished tea often has a sour and astringent taste, significantly reducing its quality. The unique processes of Puer tea create a path for post-fermentation interaction with the microscopic microbial kingdom, allowing Puer tea to embark on a long journey of aging and maturation from a simple leaf on a tea tree.

The essence of primitive agrarian civilization is preserved to varying degrees in the cultivation of tea. Puer tea, thanks to its exceptional natural environment, has been fortunate enough to retain its “natural farming methods.”

In terms of technique, each step – picking, spreading, kill-green, rolling – intertwines with the local culture and customs. The traditional tea-making skills of local ethnic minorities recreate its wild character, embodying the optimal ecological geographical value of Puer tea.

After being processed into sun-dried raw tea, Puer tea will take two different paths. One becomes raw Puer tea after compression and packaging, while the other undergoes pile-fermentation to become ripe Puer tea, which will be discussed in another article in this issue.

Generally speaking, Puer tea products after leaving the factory are considered semi-finished goods. As microbiological research into the aging of Puer tea deepens, Puer tea that has been aged in storage for a certain period is more beneficial to human health. This is the most valuable area of study for Puer tea.

The storage of Puer tea is a process of transformation in conjunction with the fascinating world of microbes. Large molecular substances in Puer tea are broken down into various smaller compounds through enzymatic fermentation, making them more easily absorbed by the body. This is the stage where the involvement of microorganisms is the greatest, leading many to view storage as an extension of Puer tea production.

In fact, the fermentation of Puer tea begins from the moment the leaves are picked. Moreover, for microbial populations, their involvement in Puer tea extends beyond the fermentation process; it can even be traced back to the growth and budding of the tea tree itself.

Different microbial communities have orderly divisions of labor, each playing its role. Mr. Chen Jie believes that while the large-leaved Camellia sinensis trees in Yunnan demonstrate the geographical value of Puer tea, the diversity and orderly division of labor in Yunnan's microbial ecology highlight its geographical value from another perspective.

The diversity of microbial ecosystems is a crucial pillar of the geographical value of Puer tea. Some of the microorganisms involved in Puer tea fermentation have evolved for over a hundred million years. Therefore, a piece of Puer tea is not just a commodity but a representation of geographical value.

From production to the final product, every stage of Puer tea's journey is intricately connected to nature. The areas where Puer tea grows typically form relatively independent three-dimensional ecosystems, such as the understory planting model that has existed on Jingmai Mountain for a thousand years. Here, tea forests coexist, and tea trees thrive alongside diverse life forms, including the parasitic species Crab Foot, creating a mutually beneficial biological phenomenon.

In the kill-green process, invisible polymorphic microorganisms remain active, preserving their potential for later conversion. Even in the simple act of drinking, Puer tea remains intertwined with nature. On a tea table, a Cup of tea serves as the best medium connecting humans to nature. A well-stored Puer tea, when consumed, conveys the essence of the wild and can be distinctly felt, allowing people to discern the storage location of the Puer tea based on its flavor. Puer tea stored in Guangdong has a mellow taste