[9] There had been no standardized processing for the darkening of hēichá until the postwar years in the 1950s, when there was a sudden surge in demand in Hong Kong, perhaps because of the concentration of refugees from the mainland.

In recent decades, demand has come full circle and it has become more common again for hēichá, including pu'er, to be sold as the raw product without the artificial accelerated fermentation process.

Ripened or aged raw pǔ'ěr has occasionally been mistakenly categorized as a subcategory of black tea due to the dark red color of its leaves and liquor.

[12] On overcast or rainy days, the leaves will be wilted by light heating, a slight difference in processing that will affect the quality of the resulting maocha and pu'er.

The leaves are then dry-roasted using a large wok in a process called "killing the green" (殺 青; pinyin: shā qīng), which arrests most enzyme activity in the leaf and prevents full oxidation.

[3]: 207  After pan-roasting, the leaves are rolled, rubbed, and shaped into strands through several steps to lightly bruise the tea and then left to dry in the sun.

[14][15][16] Although the microbes responsible have proved highly variable from region to region and even factory to factory, the key organism found and responsible for almost all pu'er fermentation has been identified in numerous studies as Aspergillus niger, with some highlighting the possibility of ochratoxins produced by the metabolism of some strains of A.niger having a potentially harmful effect through consumption of pu'er tea.

[21] It is apparent that this species does not have the gene sequence for coding ochratoxin and thus pu'er tea should be considered safe for human consumption.

The process used to convert máochá into ripened pu'er manipulates conditions to approximate the result of the aging process by prolonged bacterial and fungal fermentation in a warm humid environment under controlled conditions, a technique called wò duī (渥堆, "wet piling" in English), which involves piling, dampening, and turning the tea leaves in a manner much akin to composting.

[25] Aside from vintage year, pu'er tea can be classified in a variety of ways: by shape, processing method, region, cultivation, grade, and season.

Other lesser seen forms include: stacked "melon pagodas", pillars, calabashes, yuanbao, and small tea bricks (2–5 cm in width).

Pu'er is also compressed into the hollow centers of bamboo stems or packed and bound into a ball inside the peel of various citrus fruits (Xiaoqinggan) or sold as nuggets (Suiyinzi 碎银子 or fossilized tea 茶化石) or bundles made from tea at the center of wet piles (Laotoucha 老头茶).

The aromas can be annotated as camphora (樟香), ginseng (参香), jujube (枣香), costus (木香), minty (荷香) or very aged (陈香).

Raw pu'er is often distinguished by its floral (花香), grassy (草香), fresh (清香), herbal (药香), fruity (水果), or honey (蜜香) aroma.

[31] They are: For various reasons, around the end of the Qing dynasty and at the beginning of the ROC period (the early twentieth century), tea production in these mountains dropped drastically, either due to large forest fires, overharvesting, prohibitive imperial taxes, or general neglect.

In addition to China, border regions touching Yunnan in Vietnam, Laos, and Burma are also known to produce pu'er tea, though little of this makes its way to the Chinese or international markets.

There are three widely used methods of cultivation for pu'er: Determining whether or not a tea is wild is a challenging task, made more difficult through the inconsistent and unclear terminology and labeling in Chinese.

Many pu'er aficionados seek out and maintain relationships with vendors who they feel they can trust to help mitigate the issue of finding the "truth" of the leaves.

Until recently factories were all state-owned and under the supervision of the China National Native Produce & Animal Byproducts Import & Export Corporation (CNNP), Yunnan Tea Branch.

Pu'er tea cakes, or bǐngchá (饼茶 or 餅茶), are almost always sold with a:[37] Recently, nèi fēi have become more important in identifying and preventing counterfeits.

Some nèi fēi also include vintage year and are production-specific to help identify the cake and prevent counterfeiting through a surfeit of different brand labels.

Pu'er flavors can change dramatically over the course of the aging process, resulting in a brew tasting strongly earthy but clean and smooth, reminiscent of the smell of rich garden soil or an autumn leaf pile, sometimes with roasted or sweet undertones.

The practice of "Pen Shui" 喷 水 involves spraying the tea with water and allowing it dry off in a humid environment.

This process speeds up oxidation and microbial conversion, which only loosely mimics the quality of natural dry storage aged pu'er.

"Pen Shui" 喷 水 pu'er not only does not acquire the nuances of slow aging, it can also be hazardous to drink because of mold, yeast, and bacteria cultures.

Raw pu'er can be ruined by storage at very high temperatures, or exposure to direct contact with sunlight, heavy air flow, liquid water, or unpleasant smells.

It is often recommended to age ripened pu'er to air out the unpleasant musty flavors and odors formed due to maocha fermentation.

However, some collectors argue that keeping ripened pu'er longer than 10 to 15 years makes little sense, stating that the tea will not develop further and possibly lose its desirable flavors.

The leaves are traditionally given one or more "rinses" before the first infusion, involving exposing them to hot water for 2–5 seconds and subsequently discarding the extract produced.

Quality aged pu'erh can yield many more infusions, with different flavor nuances when brewed in the traditional Gongfu method.