7581

7581 is the legendary shú zhuān (熟砖), a compressed ripe Pu-erh brick produced by the Zhongcha (中茶) corporation at the Kunming Tea Factory, which went down in history as one of the first standardized recipes after the birth of the wò duī technology. Today, it is the benchmark for the “brick” category and an exemplar of the so-called kūnmíng wèi — the Kunming flavor profile.

1. Classification and Origin:

• Type: Ripe Pu-erh, (shú, 熟)
• Category: Compressed brick (zhuān, 砖)
• Producer: Zhongcha Corporation (中茶), Kunming Tea Factory
• Decoding the article number mài hào (唛号): A four-digit factory code introduced for recipe standardization. The first two digits (75) represent the year the recipe was created, 1975; the third digit (8) is the conventional leaf tenderness grade (the higher the number, the coarser and larger the leaf); the fourth digit (1) is the manufacturer’s factory code, where 1 is assigned to the Kunming factory (昆明), 2 to Menghai (勐海), 3 to Xiaguan (下关), and 4 to Pu’er (普洱). Thus, 7581 is deciphered straightforwardly: a 1975 recipe, eighth-grade raw material, Kunming factory.
• Origin of Raw Material: máochá (毛茶) sourced from the tea-growing regions of Yunnan
• Place of Fermentation and Blending: Zhongcha’s Kunming factory (昆明) — it is the Kunming location that imparts the final imprint onto the flavor
• Segment: A relatively mature, coarse blend of mid-grade leaves, designed for a mass, accessible market segment, rather than “tender” bud grades

2. History and Cultural Significance:

The historical value of 7581 lies in it being one of the first mass-produced ripe bricks executed by Zhongcha and the universally recognized benchmark for the “brick” category. If 7572 from Menghai is considered the standard ripe disc and the “face” of mass-produced ripe Pu-erh, then 7581 occupies a similar niche among bricks: it is the standard against which a classic, affordable Kunming-style ripe tea is judged.

The 1975 recipe dates back to a period when the industry was cementing stable article numbers and blends for its products, transitioning from artisanal variability to a reproducible standard. This is precisely why 7581 holds a dual status — simultaneously an official benchmark (a standardized product with a fixed recipe) and a historic-academic artifact (a milestone in the establishment of wò duī technology and the 唛号 system).

3. Botanical Description and Raw Material:

7581 is not a single-variety or single-garden tea, but a recipe-based blend. The eighth grade of raw material in the grading system signifies the use of mature, relatively large, and coarse leaves, far from “palace-grade” tenderness. Here, one should keep in mind the entire scale of tenderness for ripe Pu-erh: at its peak is gōngtíng (宫廷, “palace”) — the highest grade consisting of single buds and the most tender leaves, followed by tèjí (特级, superfine grade), and then descending numerical grades. 7581 deliberately sits in the lower, working part of this scale — and that is precisely why it has become a tea for everyday drinking by the common people, rather than a collector’s premium item.

This choice of raw material is not a flaw but a part of the design: coarse leaves yield a dense, resilient infusion with a solid foundation for protracted storage and numerous infusions, which is essential for a compressed brick.

4. Terroir and Cultivation Specifics:

The key feature of 7581 is that its identity is defined not by one specific garden, but by the location of its fermentation and blending. The Zhongcha factory in Kunming (昆明) works with máochá (毛茶) raw material sourced from the tea regions of Yunnan, but it is the Kunming location that imparts the final flavor imprint: the water, the high-altitude plateau climate, and, most critically, the factory’s microflora, which has become ingrained in the wò duī workshops over the years.

This phenomenon is described within the industry by the concept of wèi xíng (味型) — a regional “flavor type” of wet-piling. Alongside the Menghai (měnghǎi wèi) and Lincang (líncāng wèi) profiles, the Kunming profile (kūnmíng wèi) is considered one of the three foundational types. Kunming fermentation traditionally yields a drier, cleaner, less “heavy,” and less “muddy” character compared to the rich, earthy-sweet Menghai style — a direct consequence of the plateau’s cooler and drier climate, which influences the course of piling.

5. Production Technology:

The heart of 7581 is the wò duī (渥堆) technology, a controlled wet-piling fermentation, whose development in the mid-1970s is encoded in the “75” recipe. The essence of the process: moistened máochá is gathered into large piles, where accelerated fermentation takes place under the influence of heat, moisture, and microbiological activity. It is wò duī that distinguishes “ripe” (shú, 熟) Pu-erh from “raw” (shēng, 生), transforming originally green raw material into dark, mellow, ready-to-drink tea in weeks rather than decades.

After fermentation, sorting, and aging, the raw material is compressed into a brick shape (zhuān, 砖). The brick format was historically the most technologically advanced and economical: a dense, rectangular slab is convenient for transportation, stacking, and storage, which made 7581 a pragmatic product for widespread distribution. Unlike a disc (bǐng) or nest (tuó), the brick is associated specifically with a utilitarian, “workhorse” compression tradition.

6. Organoleptic Characteristics:

The profile of 7581 is a classic, “honest” ripe tea with no embellishments. The infusion yields a deep chestnut-red, dark color. The aroma and flavor are dominated by earthy, woody-resinous, and slightly nutty tones; characteristic is the dry cleanliness of the Kunming style, without excessive “swampiness.” The body of the infusion is dense and coating, with a soft, sweet aftertaste that gains roundness as the brick ages.

A young 7581 may carry a slight “warehouse” or fermentation note — this is normal for freshly pressed ripe tea and usually dissipates with a few years of dry, ventilated storage.

9. Brewing:

Practical brewing guidelines:

• Ware: gàiwǎn or a Yixing teapot made of dense clay, which smooths out the coarse notes of a young ripe tea.
• Water: Full boiling water (approx. 100 °C), as mature, dense leaves require high temperature for full extraction.
• Mandatory Rinse (xǐ chá): One or two short rinses to awaken the compressed leaf and wash away “piling” dust.
• Infusions: Short at the beginning, with a gradual increase in steeping time; a quality 7581 withstands many infusions without “collapsing” into empty water.

11. Price and Counterfeits:

Several pointers that help identify a “genuine” 7581 and differentiate it from adjacent items:

• Format. This is a brick (zhuān), not a disc (bǐng). If you are looking at a round cake, it is no longer a 7581 — most likely it is a 7572 or another recipe.
• Brand and Factory. An authentic 7581 is a product of Zhongcha/Kunming (represented by 1 in the code). The packaging and markings must point to the Zhongcha corporation.
• Flavor Profile. The dry, clean earthiness of the Kunming style distinguishes 7581 from the heavier, sweet-muddy Menghai profile (měnghǎi wèi), typical of Menghai recipes.
• Leaf Grade. The eighth grade signifies a noticeably coarser leaf than “palace-grade” gōngtíng or premium recipes like 7262. If the brick is dominated by small, tender buds, this is not the 7581 profile.
• Segment. 7581 has historically been positioned as an affordable, everyday, entry-level tea. A premium price and “collectible” presentation should raise questions — this is not in the nature of this specific article number.

It is the combination of these features — a brick, Zhongcha/Kunming, a 1975 recipe, coarse mature leaf, and a dry-clean Kunming taste — that makes 7581 recognizable and a deservedly benchmark representative of its category.

12. Interesting Facts:

• The number 7581 encodes its entire “pedigree”: the recipe’s year (1975), the leaf grade (eighth), and the factory (Kunming, digit 1) — this is a model of the factory system of article numbers mài hào (唛号), which replaced artisanal variability.
• The Kunming flavor profile (kūnmíng wèi) is one of the three foundational “flavor types” (wèi xíng, 味型) of wet-piling, alongside the Menghai (měnghǎi wèi) and Lincang (líncāng wèi) profiles.
• 7581 and 7572 form a benchmark pair for mass-produced ripe Pu-erh: 7572 is the “face” of ripe discs from Menghai, while 7581 is the benchmark for ripe bricks from Kunming.