De-stemming and de-veining
Separating stem and leaf vein from the leaf blade after drying, usually by air separation.
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
A sorting step with disproportionate consequences. Removing stem and vein is what turns aracha into tencha for matcha, and what makes gyokuro’s liquor clean rather than woody. The removed fraction is not waste: it becomes kukicha, a genuine tea in its own right with a sweeter, lighter character than the leaf it came from. So one sorting decision produces two distinct products from one harvest.
Also transliterated as: senbetsu.
What it does to the leaf
Separates leaf blade from stem and coarse vein, standardising the material that goes into the finished tea.
What it does to the cup
Removes woody and vegetal notes from the leaf fraction; the stem fraction is sweeter and lower in astringency.
Variants that matter
Ways this step is carried out that produce genuinely different results, rather than regional names for the same thing.
- Air separation
- Standard in modern Japanese processing; stems and blade have different densities and are parted by airflow.
- Hand sorting
- Still used for the highest grades of tencha, where a single stem fragment in the mill affects the whole batch.
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.
- 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.
- 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.
- 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
This page is TeaHQ’s own synthesis of well-attested production practice. No external technical document stands behind it, so it describes what producers do rather than asserting measured process parameters.
Written comparisons
Where TeaHQ has set this step against something it is routinely confused with, and argued the differences out in full.
- Sorting and grading vs de-stemming — Two separation steps that between them produce almost every grade name a drinker will ever read, and neither is a quality judgement. Sorting separates finished leaf by size and density; de-stemming separates stem and coarse vein from the blade.
In the chronology
- The technique matures across the Edo period and is mechanised in the twentieth century — Tencha, the stone mill, and why matcha is expensive