Sheng Pu'er — The “Foundation” Trilogy, Part II

Sheng, also known as raw, “green,” or raw pu’er — is a living tea from Yunnan province, the polarity of shu pu’er. Do not confuse it with green tea! Unlike green tea, the processes of fermentation in sheng are not stopped, which allows the tea to change and transform throughout its entire life, like a living organism. To begin, let us clarify the general definition of pu’er.

Pu’er (普洱茶) is not a separate type of tea as such (see: the six categories of tea), but rather a derivative of post-fermented tea — a collective term. A tea type is defined only by its production technology, but in order to be called pu’er, a tea must meet a broader set of criteria: 1. Geography — produced in Yunnan province 2. Raw material — the large-leaf Yunnan variety of the tea tree is used 3. Processing — a specific production technology (outlined below)

It is important to note that these criteria are established by the Chinese national standard (GB/T22111-2008), not by an international one, and therefore do not apply outside of China. As a result, even though they fall outside Chinese regulations, pu’er is also produced in neighboring countries such as Thailand, Myanmar, and Laos. The raw material is the same — the large-leaf Camellia sinensis — a plant to which national borders mean nothing.

The term “pu’er tea” in itself says nothing, since depending on processing it is divided into two fundamentally different types:

→ sheng 生 → shu 熟

The production technology of sheng pu’er:

→ Harvesting the leaf 采茶

→ Sun-withering 晒青

→ “Killing the green” (sha qing / fixation) 杀青

→ Rolling (rou nian) 揉捻

→ Final drying (wei diao) 萎凋

→ Compression 圧制

→ Transformation over time / post-fermentation 后发酵

Harvesting the leaf

Leaves are hand-picked from March to October. Seasonal weather conditions directly influence the taste and aroma profile of the tea. Typically, the terminal bud with the two closest young leaves is plucked — these are called flushes.

Sun-withering

A key stage in pu’er production that distinguishes it from other teas. Withering gives the leaf’s microflora the signal to prepare for the subsequent “killing the green,” as if placing them into a suspended state. This ensures the survival of the bacteria and fungi required for later post-fermentation. The leaf becomes somewhat dry and flexible.

Some second-rate factories skip this step, but this is clearly evident in the tea’s poor and uneven aging — such teas are certainly unfit for long-term storage in a collection.

Killing the green

Oxidation processes in the leaves are halted by pan-firing in a dry wok at about 200 °C, but not completely as in the production of green tea — only partially, since the leaves must retain the enzymes on which subsequent post-fermentation depends. The firing is done by hand, with the master controlling both quality and evenness of heating. Occasionally, large factories replace hand-firing with cylindrical ovens, but this is an exception that negatively affects the product’s quality. After firing, the leaves are spread out, cooled, and after 10–20 minutes proceed to…

Rolling

To release juices and give the leaf its characteristic form, it is hand-rolled using a bamboo sieve.

Final drying in the sun

The main distinction between sheng processing and green tea lies in the drying method: after rolling, raw material for sheng is not dried in a hot oven (hong qing) or on a pan (chao qing), but instead spread out on bamboo trays or a cemented courtyard and turned regularly, letting the sun do the work. With this approach, the temperature of the leaf does not artificially increase, allowing sunlight to initiate the fermentation process: moisture, enzymes, and microorganisms remain within the leaf, and the green color is preserved. The stomata on the surface reopen, enabling free respiration, while the rate of internal enzymatic oxidation slows — which later allows tea substances to be fully extracted during brewing.

It is important to note that the key variable here is not sunlight per se, but the low drying temperature — in poor weather, ovens may also be used, but only at minimal heat.

At this stage the raw material is called mao cha (毛茶) — “rough tea” or “crude tea” — and by law it is not yet pu’er (though most of the tea community doesn’t care, and we still call it loose sheng).

Before shaping, mao cha can undergo an additional stage of moist piling (wo dui), thereby transforming into shu pu’er — but today we are talking about its polarity, sheng.

Compression

The leaves are lightly steamed, then distributed into cloth bags, whose ends are twisted into a knot in the center (as a result, the cake retains an indentation on one side). The bag with mao cha is placed into a metal mold and pressed with a stone weight. Traditionally, the technician would stand on the press for a few seconds, adding body weight to increase the pressure. Nowadays, large factories may use hydraulic presses.

After pressing, the cake is removed from the bag and sent to dry, a process lasting from several weeks to several months. Once drying is complete, the cake is wrapped in rice paper and branded packaging.

The tradition of compressing tea into cakes originated in Yunnan as a way to ensure more convenient transportation along the ancient Tea-Horse Road to Tibet. The 357-gram cake (bing cha, 饼茶) is the most common, but by no means the only form — other frequent shapes include: nest (tuo cha, 沱茶), brick (zhuan cha, 砖茶), gourd (jin gua cha, 金瓜茶), etc. Sometimes tea is packed to mature inside a bamboo stalk, a mandarin orange, or even a pomelo.

Hand-pressed cakes from smallholder production are quite delicate — they can be easily broken apart “by hand into pieces.” Machine-pressed factory products, on the other hand, require not only more effort but also a tool, such as an awl. When prying apart such tightly compacted cakes, one must be especially attentive and careful — otherwise, there’s a real risk of losing a finger.

Post-fermentation

As in other teas, in pu’er a chemical reaction occurs between the leaf’s organic compounds and oxygen with the participation of enzymes — oxidation. However, the defining feature of pu’er is fermentation — still organic chemistry, but the result of the biological activity of microorganisms (bacterial metabolism). Post-fermentation is made possible thanks to the initial sun-withering of the leaf, without which the bacteria and fungi necessary for the process would be destroyed during wok-firing. Fermentative processes include, among others, the breakdown of polyphenols and the synthesis of complex esters (the latter being responsible for the pleasant, aged aroma).

It is often the case that mao cha is stored for a couple of years in loose form before being pressed — it is believed that fermentation and aging progress more quickly in uncompressed tea, but become more interesting once compressed. The development of a cake’s taste and aroma depends on the density of the press (the tighter, the slower oxidation proceeds), as well as the temperature and humidity of the storage environment. The higher the humidity, the faster the changes in the tea — though the trajectory differs significantly from long-term aging in a drier climate.

Pu’ers mature continuously throughout their storage:

→ Young shengs (up to 4–5 years) The cakes remain greenish in color, with a fresh taste of greenery, meadow herbs, flowers, and sometimes marine notes. They are fairly bright, but often wild and unruly, requiring very careful brewing — best to cool the water slightly and pour off the infusion after literally 3–5 seconds. With experience, one discovers their own preference. The state induced by young sheng is invigorating and playful. This tea is most active in contact with the mucous membranes and thus should not be drunk on an empty stomach.

→ Middle-aged (5–15 years) These become amber in appearance, somewhat “rounded,” softening their former sharpness, and thus can be handled more boldly — confidently using boiling water and allowing a 7–15 second steep. Since sheng is often considered a “raw product,” at this stage it is thought to be “already drinkable”, as it reveals its best sides. But as the saying goes — to each their taste!

→ Elders (over 15 years) These darken to deep brown, acquiring the prefix lao — “aged.” Their taste-aroma palette transforms into notes of antiquity, camphor, medicinal balms, and old library books (chen xiang, 陈香 — the “aroma of agedness”). The liquor becomes significantly deeper, more complex, and shimmering. The tea “calms down,” becoming less stimulating and more meditative-sedative in its effect. A truly unique beverage, one that takes many sessions to fully understand. It is important to note, however, that finding a well-aged quality cake is no simple task.

The most fascinating part, of course, is observing the cake’s transformations year after year, noting its progression in organoleptics and in tea energy (cha qi).

Important‼️

The raw material is of paramount importance in sheng pu’er, for these teas embody the “taste of nature” (zi xiang, 自香) — their processing merely highlights and preserves what already exists in the leaf, while the master leaves almost no “personal imprint.” By contrast, in other teas — shu, oolongs, red/black teas, etc. — the “taste of craftsmanship” (gong xiang, 工香) is formed by the intervention of the tea master through processing techniques. Exactly for this reason, in sheng pu’er the geographical origin of the raw material plays a primary role, unlike in other teas where processing technology is the decisive factor.

Raw material > age

Garbage in, garbage out — no matter how many years low-grade leaves “from the roadside” are aged, they will never become better; while the most delicious, multifaceted aged shengs are such primarily thanks to the use of high-quality leaf. Age transforms tea only by amplifying or suppressing the characteristics already present.

Key variables in choosing sheng

All of the variables mentioned earlier in the section on tea botany are certainly important, but we can add a few more here:

Origin of the raw material

Bush material is quite capricious in brewing and tends to be less balanced, often giving a more stimulating, sharp, coarse, and “rough-hewn” effect. Trees, on the other hand, have a richer biochemistry and, as a result, a deeper, longer, more oily taste, pronounced hui gan (returning sweetness), and a harmonious effect. Thus, trees — for example, small trees (xiao shu) — are my recommendation for a first acquaintance.

Usually, raw material is blended from different plantations, mountains, or trees, but the most premium offerings are sometimes pressed from the material of a single specific tree.

Region of harvest

This matter is highly subjective, and I will not claim my own favorite locations to be the “best.” I will only say that gradual, attentive acquaintance with different regions will eventually bear fruit, shaping your personal taste.

It is also important to note that even here the Chinese may mislead, collecting raw material on the far outskirts of a famous terroir, while still putting that prestigious name on the packaging to create the image of high quality.

And, moreover — tea is not limited to China alone! It is essential to also taste teas from other countries such as Thailand, Vietnam, etc. Knowledge arises through comparison.

Season of harvest

Spring harvest, particularly the first and second after winter, is considered the best, giving a bright, juicy, and strong result. Autumn harvest yields a calmer and softer tea, with less caffeine and less bitterness. Summer harvest lies somewhere in between spring and autumn — generally, the plant has not yet fully replenished its reserves of beneficial substances after the spring pick; nevertheless, such tea has its place, and interesting examples can occasionally be found.

Type of raw material

…is determined by the ratio of buds to leaves. Buds make the beverage stronger, more invigorating, more active. Leaves, in turn, will give different results depending on their maturity.

Production environment

…directly affects the quality of the processing. • Factories often develop their own recipes, repeating the same procedures year after year in an identical manner — a double-edged sword. Acquaintance with factory teas should begin with the most renowned producers (Menghai / Da Yi, Haiwan, Xiaguan, Yongming, Yongzhen, etc.). • Craft/farmer productions are distinguished by a more homely and meticulous approach, as well as much smaller and more controlled volumes of production. Farmer teas are unquestionably the most interesting and unique — the difference from factory teas is immediately noticeable. • Master teas can be either factory-made or farmer-made. Their essence lies in the tea master, a technologist who has established a reputation as a professional in a particular approach to production. To appreciate such teas requires a certain level of developed tea experience.

In conclusion — shengs, like a good book, demand attention and thoughtfulness. Their hues do not shout or clash like in a blockbuster film or theatrical performance, but are subtle and profound, requiring a contemplative mind. Cinema happens outside of you and penetrates only to a certain depth, while a book unfolds within your inner world, drawing on the material of your own soul. Even the most unusual theatrical production grows dull by the second day, but a good book can be reread dozens of times, each time revealing something new.