Xu Yahé: The premise for ‘aging to richer flavor'
is to get the initial setup right for Pu'er tea
The tea expert Xu Yahé once introduced a new concept of Pu'er tea storage called “Nurture, Guide, Influence, Control.” Based on this concept, with his rich experience in making tea and participating in numerous Pu'er tea evaluations, he will explain how to achieve the initial setup for Pu'er tea's ‘aging to richer flavor' before its production, following national standards. He hopes to provide readers with useful information and insights.
Want ‘aging to richer flavor'?
First, check if it's the right ‘material'
According to Xu Yahé, from the perspective of raw materials, the results for ‘aging to richer flavor' differ for first-grade, second-grade, and third-grade teas. “I believe that the concept of ‘aging to richer flavor' is targeted at specific teas, guiding and controlling their quality in a particular direction. Only good-quality teas are worth storing; otherwise, they should be consumed sooner.” To Xu Yahé, Pu'er tea storage is like a school where only the best students with solid foundations can enter.
What constitutes a good foundation?
First, select the right material
Which type of tea has the initial conditions to reach the desired destination after a long process of post-fermentation? Xu Yahé believes that the first element is selecting the correct category of tea. The chosen tea must be standard Yunnan large-leaf Pu'er tea. Xu Yahé is somewhat helpless about the current overly personalized Pu'er tea market and calls for tea makers to re-focus on and implement the national standards for Pu'er tea.
The national geographical indication for Pu'er tea includes three strict limitations. The first is the origin restriction. The raw materials must come from 75 counties within Yunnan Province, across 11 prefectures. Raw material sources should not depart from these designated areas. Although some border teas have entered the market, Xu Yahé believes that regardless of their taste, tea merchants should not introduce such raw materials. “Foreign raw materials should never be compromised as it amounts to fraud. I suggest all tea companies should voluntarily avoid using raw materials from areas outside the designated production regions.” On this issue, he is very principled.
Sun-Drying is the most important process in Pu'er tea production
National standards emphasize that Pu'er tea is made from sun-dried raw tea, which is produced from Yunnan large-leaf tea processed in Yunnan. In the indicators for sun-dried raw tea, the word “sun-dried” comes first. Pu'er tea raw materials must be sun-dried because during the drying process, the tea leaves come into intimate contact with microorganisms in the air. It acts like a culture medium, inoculating beneficial microorganisms as it interacts with the air.
Using the issue of sun-drying, Xu Yahé re-explains the processes of oven-drying and pan-frying, “Why do we not advocate oven-dried or pan-fried teas? Oven-dried teas are dried at high temperatures, which eliminates the low-temperature bacteria present initially. The remaining bacterial colonies would be different from those produced by sun-drying. Pu'er tea oxidation has three paths in the later stages, which we call aerobic, anaerobic, and microbial. Oven-drying and pan-frying reduce the storage of Polyphenol oxidase in the tea leaves, weakening the foundation for enzymatic oxidation later on.”
For example, if we want the tea to exert its full strength, we end up with Black Tea. Sun-dried raw tea is different. During the fixation process, there is also ‘leaving green,' which preserves the most important substance – enzymes. We generally kill about 70-80% of the enzymes, leaving roughly 20-30% for future conversion. Oven-drying eliminates even this remaining margin. The speed of later conversion slows down, so we must use the standard sun-drying method to create conditions for microorganism storage.”
Apricot Yellow Bright:
The sensory evaluation standard for sun-dried raw tea (sheng)
In national standards, the standard color for sun-dried raw tea (sheng) is apricot yellow, described as “apricot yellow bright.” Xu Yahé further defines the boundaries of “apricot yellow bright”: green apricot yellow, yellow apricot yellow, or a color between the two, all qualify as acceptable. If the green apricot yellow leans more towards green, the tea is closer to green tea. Additionally, the standard color must exhibit yellow, with green having a yellow tinge. If yellow turns red, fermentation has occurred in the production process, deviating from traditional Pu'er tea methods.
Some people seek unique mouthfeel qualities and moderately cover the tea during sun-drying, reducing bitterness and astringency. Xu Yahé believes this is acceptable but emphasizes that the green must not be completely covered; the baseline must remain “yellow with a green tint, green with a yellow tint.” Xu Yahé says, “We do not advocate withering or heavy covering. If the color is yellow, there must still be green visible, and if it is green, there must still be yellow visible, within this range. Of course, the leaf base cannot show red stems or edges, as red is a warning color indicating enzymatic oxidation.”
We often mention large-leaf sun-dried raw tea, but what exactly are the standards for true large-leaf sun-dried raw tea? No one interprets them. What does “apricot yellow bright” truly look like? Perhaps a thousand people have a thousand interpretations of “apricot yellow bright.” This means that although standards have been established, no one has truly studied the exact boundaries. Strictly adhering to the standards is not easy, and perhaps creating a national standard color chart could solve this problem.
Red Brown Bright:
The sensory evaluation standard for ripe tea
“According to national standards, the color of dry ripe tea should be red brown, similar to liver color, and appear uniformly across the surface, which can be called the standard color. The standard for liquor color is red brown bright. National standards describe it as ‘red, thick, and bright,' but I believe ‘red brown bright' is more accurate. In our usual tea evaluations, the focus on ripe tea colors is primarily on hue. If the hue indicator shows only red without brown, the tea is red liquor and red leaf black tea. Having red brown is not enough; it must also be bright. What is bright? Being able to see it clearly is called bright, and reflecting light is called shiny. This is the standard liquor color for ripe tea.” As he speaks, Xu Yahé opens the gaiwan with two infusions of ripe tea, pointing and saying, “Look at the color of this ripe tea leaves, a bit dark, showing only brown without red. According to the standards, this ripe tea has undergone heavier fermentation.”
Next, smell the aroma of the ripe tea. After fermentation, the tea carries the heap scent of fermented tea. This scent is normal for ripe tea since it has just left the heap. “However, the heap scent must not be pungent. It should be slightly humid with a hint of Sugar fragrance because many fibers are converting inside, resulting in a complex mix of aromas that eventually combine into a scent similar to turtle jelly. This is the dominant aroma. There may be accompanying aromas that appear in the first and second infusions but disappear afterward. The aroma that persists throughout is the dominant aroma. In our evaluations, we conduct hot, warm, and cold sniffing to find the main aroma line. Such ripe tea, regardless of storage, will ultimately revolve around the dominant aroma and not deviate.”
The quality of tea is designed
Xu Yahé proposes a viewpoint: the quality of tea is designed, closely related to the proportion of raw material grades. If one wants a tea with a stronger bitter taste, choose one bud with two or three leaves; if one wants a sweeter tea, choose a lower grade, such as seventh or eighth grade; for a lighter taste, select one bud with one leaf or even finer raw materials… This requires the tea maker to be very experienced to achieve the intended quality design.
When Pu'er tea selection is standardized, it proves that the foundation has been laid, and the focus of the tea made should shift to storage, specifically the “guidance” aspect of “Nurture, Guide, Influence, Control.” The direction of guidance depends on market demand. “For example, people