Definition:
Pu-erh processing encompasses the production steps that transform fresh tea leaves from Yunnan’s large-leaf Camellia sinensis var. assamica cultivars into pu-erh — a post-fermented tea category characterised by its microbial transformation and capacity for long-term aging. There are two main types: raw (sheng) pu-erh and ripe (shou) pu-erh, produced by different processing paths.
Shared Early Steps
Both sheng and shou pu-erh begin with:
- Harvest — Large-leaf Yunnan cultivar leaves are hand-picked, often from ancient trees (gushu)
- Wilting (wēi diāo) — Brief natural wilting to reduce moisture and soften the leaf
- Kill-green (shāqīng) — Pan-firing in a large wok to halt enzymatic oxidation. Unlike Japanese green tea (steamed), the pan-firing is done at lower temperatures and is less thorough, leaving residual enzymes that enable future transformation
- Rolling (róuniǎn) — Shaping the leaf and rupturing cell walls to release juices
- Sun-drying (shài qīng) — The leaves are dried in sunlight, preserving microbial activity. This distinguishes pu-erh from other green teas, which are kiln-dried.
The result is maocha — the raw, uncompressed base material.
Raw Pu-erh (Sheng / Green Pu-erh)
Maocha is steamed and compressed into cakes, bricks, or tuos and then stored. Natural aging occurs slowly over years or decades — a combination of microbial activity, oxidation, and enzymatic change transforms the character of the tea. Young sheng is often green and astringent; well-aged sheng becomes smooth, complex, and earthy.
Ripe Pu-erh (Shou / Cooked Pu-erh)
Developed in Yunnan in 1973 to simulate the character of aged sheng in a fraction of the time. After maocha preparation, the leaves undergo wò duī (wet-pile fermentation):
- Maocha is piled into heaps, moistened with water
- The pile heats up through microbial activity (primarily Aspergillus niger and other fungi/bacteria)
- The pile is regularly turned over weeks (typically 30–60 days)
- Temperature and moisture are carefully monitored
- The result is a heavily transformed, dark leaf with earthy, composty character
After wò duī, the leaves are dried, then typically compressed.
Compression
Both types are often compressed into standard shapes:
- Bingcha (cake): flat round disc, typically 357g or 400g
- Zhuancha (brick): rectangular
- Tuocha (nest): small bowl-shaped
Compression allows for more efficient storage and transport, and affects how the tea ages.