From the tea tree to the tea leaves, and from the tea leaves to the teacup, temperature seems to accompany tea all along.

The raw material for Pu-erh tea is sun-dried green mao cha from Yunnan's large-leaf varietal. This Yunnan large-leaf species is a famous, fine tea plant cultivar in China, a general term for the large-leaf tea plant varieties in Yunnan Province. It mainly includes the Mengku large-leaf species (also known as Big Black Tea), the Fengqing large-leaf species, and the Menghai large-leaf species, among others. It has weak cold resistance, suffering severe frost damage below -5°C. It is suitable for making black tea. The fresh leaves are rich in tea polyphenols and catechins. In recent years, there have been more than 20 varieties of Yunnan large-leaf tea plants. The production process for sun-dried green mao cha has also been updated several times. But let's get back on topic.

Like other soil-grown plants, the growth of Yunnan tea trees requires a certain temperature range for survival and development.

On sunny days, during the period after tea leaves are picked from the tree and before withering, if they are not withered promptly, the piled-up fresh leaves can generate excessive internal heat, affecting the tea's quality. Temperature continues to influence tea quality throughout the stages of making sun-dried green mao cha: withering, fixation (kill-green), rolling, yellowing, and drying. Currently, judging by the skill level of production personnel and equipment in tea regions, each stage largely relies on "experience." Of course, a small portion relies on technology and equipment rather than just experience. A current consensus is to keep the temperature during drying below 60°C. For many other stages, there are no fixed temperature standards.

On rainy or overcast days, due to the increased water content in the leaves, if the same temperature is used, processing time lengthens. If the temperature is increased, the quality of the tea relatively declines.

In the wet-piling fermentation process for ripe Pu-erh tea, mastering temperature is of paramount importance. Excessively high temperature can lead to over-fermentation and a burnt core, while too low a temperature results in insufficient fermentation. Currently, there is no scientifically defined standard for the degree of fermentation.

After being made into sun-dried green mao cha and before being pressed into compressed tea, temperature also has a certain impact during storage or the refining process. If the temperature is too high, the weight of the mao cha decreases; the mao cha becomes brittle, leading to more broken leaves during processing.

During the production of compressed tea, some ripe Pu-erh is rinsed once, then steamed (generally above 100°C), followed by drying in a baking room or natural air-drying. The drying temperature is also crucial.

When the tea finally reaches the person brewing it, mastering the water temperature is essential. If a brewer can control the water temperature well, then any tea in their hands will become a good tea.