màihào

A four-digit code like 7542 on a pu-erh cake wrapper is neither a production year nor a weight — it is a màihào (唛号), a factory recipe number. Understanding its logic separates a meaningful purchase from guesswork based on packaging alone.

What a 唛号 is and where it came from

The character 唛 (mài) is a phonetic borrowing that conveys the English word “mark”, i.e. “marking” or “article number”. In the context of pu-erh, màihào (唛号) is a standardised commodity code assigned to a specific recipe of the large state-owned tea factories of Yunnan. The system in its modern form was introduced in 1976, when the export and production structure of the industry required a uniform way to designate recipes — repeatable blending “formulas” according to which the same product was assembled year after year.

A key idea to grasp right away: a 唛号 describes a recipe, not a batch. It is an article number in a catalogue, not a date or an indicator of ageing. Two cakes bearing the same number, pressed decades apart, belong to the same recipe line but may differ radically in age, storage, and the character of the infusion.

How the code is read: digit by digit

A classic 唛号 for pressed tea consists of four digits; for loose máochá a five-digit version is used. The breakdown of a four-digit code is read by position:

• [1–2] — Year of the recipe. The first two digits indicate the year in which the recipe was developed and approved. This is the “birth year of the formula”, not the year the specific cake was made.
• [3] — Grade (tenderness) of the raw material. The third digit designates the leaf grade on the tenderness scale: the smaller the digit, the more tender the material. This is an averaged characteristic of the blend, not a strict single grade.
• [4] — Factory of origin. The last digit is the factory code number.

Codes of the main factories:

Digit	Factory
1	Kunming (昆明) / 中茶
2	Menghai (勐海) / 大益
3	Xiaguan (下关)
4	Pu-erh (普洱)

Putting the positions together, the code 7542 is read as follows: a recipe from 1975, raw material of tenderness grade 4, Menghai factory (factory No. 2).

Benchmark numbers worth knowing

Over the decades, several 唛号 have become industry reference points — the perception of a category is essentially calibrated against them.

• 7542 — 1975 recipe, grade-4 raw material, Menghai factory. This is the benchmark shēng bǐng (生饼), raw pressed pu-erh. It is used as a “reference sample” of a raw cake.
• 7572 — the benchmark shú bǐng (熟饼), fermented (shu) cake from the Menghai factory. Following the logic of the code: 1975 recipe, grade-7 raw material, factory No. 2. This is the most recognisable reference for ripe pu-erh.
• 7581 — shú zhuān (熟砖), a fermented brick from the 中茶 factory (factory No. 1, Kunming).

It is useful to keep these three numbers in mind as anchor points: they show how the same four-digit framework encodes a raw cake, a shu cake, and a shu brick from different factories.

唛号 and the tenderness scale of shu pu-erh

The third digit of the code is directly linked to the raw material grading system, which is especially clear for fermented (shu) pu-erh. The tenderness grades of máochá are arranged from the most tender to the coarsest as follows:

宫廷 (gōngtíng) > 特级 (tèjí) > 一级 > 三级 > 五级 > 七级 > 九级

That is, from “palace grade” (the tiniest, bud-rich shoots) to large, coarser leaf. In a màihào the third digit reflects precisely this axis: a smaller number means a more tender fraction forms the basis of the recipe. That is why in 7542 the digit “4” signals a finer blend than the “7” in 7572, which is consistent with the former being the benchmark raw cake and the latter the benchmark shu.

It is important to understand the boundary: the grades 宫廷／特级／一—九级 describe the raw material and its tenderness, not the quality of the finished beverage nor the variety of the tea bush. A high grade means that young, fine shoots predominate in the blend, but it does not automatically guarantee a “better” taste — for ripe pu-erh the balance of coarse and fine fractions is often precisely what forms the body and structure.

Taste, brewing, and what the code says about the cup

A 唛号 on its own does not describe the taste of the finished cup — it sets a framework of expectations. The benchmark raw cake of the 7542 recipe line is about a dense, structured profile of raw pu-erh that unfolds and changes with years of storage. The shu references 7572 and 7581 are about a warm, earthy-woody, smooth infusion of fermented tea, ready to drink sooner.

What is absent from the code is of decisive importance for the final taste: the actual year of pressing, the conditions and duration of storage, the warehousing humidity. That is precisely why two “identical” 7542 cakes in the cup can diverge like a young and a mature wine from the same estate. The code sets the grade of raw material and the blending logic; time and the warehouse write the rest.

When brewing, one should rely on the type of tea encoded by the number (raw or fermented cake, brick) and on the age of the specific sample, rather than on the number itself — it only hints at which recipe family the tea belongs to.

History and culture of the system

The emergence of the màihào system in 1976 reflects an era when Yunnan tea was produced and distributed within a planned, export-oriented system of large state factories. The unified code solved a practical task: it made it possible to order, ship, and reproduce specific recipes regardless of the year, without having to describe the blend composition in words each time. Over time, the most popular numbers acquired a reputation and became household names — today 7542 and 7572 are recognisable far beyond factory documentation and serve as semantic “benchmarks” for the categories of raw and shu pu-erh.

In this way, factory book-keeping became part of the cultural language of pu-erh: collectors and merchants say “seventy-five forty-two”, meaning an entire recipe tradition rather than a single batch.

How to avoid mistakes when reading a 唛号

A few practical pointers so that the code works for you rather than misleading you:

• Do not confuse the recipe year with the year of production. The first two digits are the year of the recipe, not the pressing date of a specific cake. The age and provenance of a batch must be established separately.
• A 唛号 is not a storage marker. The code says nothing about how or where the tea was aged; age and warehousing are judged by the tea itself and accompanying information.
• Read the last digit as the factory. Identify the manufacturer straight away: 1 — Kunming/中茶, 2 — Menghai/大益, 3 — Xiaguan, 4 — Pu-erh.
• The third digit is raw material tenderness, not quality. A smaller number means a finer blend, but not automatically a “better” tea.
• Remember the length of the code. Four digits — a pressed product; five digits — loose máochá.

Once you master this framework, you stop seeing a mysterious string of numbers on a wrapper and start reading it as a short reference: the recipe year, the leaf grade, and the factory — leaving room for the main question about any pu-erh that the code does not answer: how old is this tea and how was it stored.

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Related topics: 唛号 and shu pu-erh, village origins and tree age, production eras — are covered in dedicated sections.