Pearl forming (chao gan cheng yuan)
Working rolled leaf against the wall of a heated pan through successive pans until each piece closes into a hard sphere, drying and shaping in the same operation.
The categories this step defines
In tea, processing is not a modifier applied to a category — it is what creates the category. These are the types that exist because this step exists.
- Green tea — Kill-green (fixation) applied before meaningful oxidation can develop.
What it is
The operation that makes a gunpowder a gunpowder, and the reason 珠茶 is classified in Chinese as 圆炒青 — the round member of the pan-fired green division, beside the long-shaped and the flat-shaped. After an ordinary fixation and rolling, the leaf goes into a series of pans, reported as 炒二青 and 炒三青 and then the shaping pair 对锅 and 大锅, where it is turned continuously against a heated surface. Each piece tightens on itself as it loses water, and by the last pan it has closed into a dense pellet that is already dry. The shaping and the drying are the same act, which is what separates this from every other way of making a compact leaf: a cloth-rolled oolong is shaped wet and dried afterwards, and a gunpowder pellet has no wet stage to unfurl from. Grades are then split by pellet size, and the smallest — pinhead — is the one the nineteenth-century export trade paid most for.
Also transliterated as: chao gan cheng yuan, dui guo, da guo.
What it does to the leaf
Compresses each piece of leaf into a sphere by continuous agitation against a heated pan wall while driving off moisture, so that shaping and drying happen together and the finished pellet is hard rather than pliable.
What it does to the cup
The prolonged pan contact contributes a toasted, slightly smoky edge that ordinary basket-dried greens do not have, and the tight sealed pellet slows the loss of that character in storage — which is why gunpowder survives long shipping and long shelf lives better than any other green tea.
Variants that matter
Ways this step is carried out that produce genuinely different results, rather than regional names for the same thing.
- Standard gunpowder
- Pellets of a few millimetres upward. The bulk of the North African trade, where the tea is brewed hard with mint and sugar and is chosen for durability as much as for flavour.
- Pinhead
- The finest grade, worked until the pellets are only a few millimetres across. More pan time per unit of leaf, which is what makes it expensive and also what deepens the toasted character.
Where this gets misdescribed
That gunpowder is rolled in cloth like a Taiwanese oolong because both end up round. The oolong is kneaded cold in a wrapped bundle and dried afterwards; this is worked hot in an open pan and is dry when it comes out. Nothing about the two operations is shared except the finished shape.
Other steps at the Rolling and shaping stage
- Blending to a standard — Combining lots so that a named tea tastes the same in March and in October, which is a manufacturing step performed on finished tea and not a compromise applied to it afterwards.
- Cloth-ball rolling — Wrapping leaf tightly in cloth and repeatedly kneading and unwrapping it until it forms tight spheres.
- CTC (crush, tear, curl) — Leaf passed through counter-rotating toothed rollers that cut it into small uniform granules.
- Curling and down-raising (cuo tuan xian hao) — Rubbing warm leaf between the palms into loose balls and breaking them apart repeatedly, which curls the leaf into spirals and lifts its down to the surface.
- De-stemming and de-veining — Separating stem and leaf vein from the leaf blade after drying, usually by air separation.
- Flat shaping — Pressing leaf flat against the side of a heated wok by hand during pan-firing.
- Needle shaping (li tiao) — Shaking fixed leaf along heated parallel grooves until each piece straightens into a needle, rather than twisting it into a curl.
- Orthodox processing — The older manufacturing route, in which leaf is twisted and rolled rather than cut, so it survives largely intact.
- Refining (shiage) — The second factory. Japanese green tea leaves the producer as aracha, an unfinished trade good, and is cut, sorted and separated elsewhere into the several named teas one intake contains.
- Repeat rolling and roll-breaking (fu rou) — Rolling is done in two or three passes with the compacted lumps broken up and sifted between them, because one long pass tightens the outside of a ball of leaf and never reaches the middle.
- Rolling and shaping — Working the leaf to rupture its cells and give it a form that governs how it later brews.
- Rotorvane maceration — A screw press with internal vanes that macerates withered leaf continuously, sitting between orthodox rolling and CTC rather than belonging to either.
- Sorting and grading — Separating dried tea by particle size, density and colour into the grades it is sold as — a sorting operation, not a quality judgement.
- Stalk picking (jian ti) — Hand removal of stalk and yellow leaf from finished oolong, done between roasts rather than at the end — which is why it is an ordering fact and not a tidying-up one.
- Stone milling — Grinding de-stemmed tencha into powder between slow-turning granite wheels.
- Strip rolling — Rolling leaf into long twisted strips rather than compressing it into balls.
Teas that go through this step
Sources
- TeaHQ editorial synthesis — TeaHQ
- 圆炒青绿茶 / 平水珠茶 — the round pan-fired green tea manufacture — Consolidated Chinese-language tea-manufacture writing on 炒青 green tea classes