CTC (crush, tear, curl)

What it is

Developed in Assam in the 1930s and now the dominant manufacturing route worldwide by volume. Withered leaf is fed through pairs of toothed cylinders turning at different speeds, which crush, tear and curl it into hard granules of consistent size. Because the leaf is comprehensively ruptured, oxidation proceeds fast and evenly, and the finished granule gives up almost everything it has within two or three minutes. Nearly every teabag in the world contains CTC tea, and it is what makes a strong, coloury cup through milk achievable at commodity prices.

What it does to the leaf

Comprehensively ruptures and cuts the leaf into uniform granules, maximising surface area and speeding both oxidation and later extraction.

What it does to the cup

Fast, strong, deeply coloured and brisk, at the cost of aromatic complexity and multiple infusions.

Variants that matter

Ways this step is carried out that produce genuinely different results, rather than regional names for the same thing.

Legg cut

A rotary cutting stage used ahead of CTC rollers in some factories to pre-size the leaf.

Granule grading

Output is sorted by particle size into BP1, PF1, PD and Dust, which describe extraction speed rather than quality.

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.
• 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.
• 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

• Argentine black tea
• Atherton Tablelands tea
• Burundian black tea
• Cameron Highlands black tea
• Cameroonian black tea
• Chai blend base
• CTC black tea
• Jhapa CTC
• Mambilla tea
• Mozambican black tea
• Rwandan black tea
• Sylhet tea
• Ugandan black tea
• Wahgi valley tea
• Wush Wush tea
• Zimbabwean black tea

Guides covering this step

• Why black tea tastes malty — Full oxidation rebuilds the leaf’s flavour compounds into larger coloured ones, trading fresh and vegetal character for malt, dried fruit and cocoa — and the leaf variety decides how far that goes.
• How one machine changed the world tea trade — Crush, tear and curl was a manufacturing change that turned into an economic one. It made tea cheap, strong, fast-brewing and suitable for a bag, and in doing so it decided what most of the world means by the word tea.
• Whole leaf, broken, fannings and dust — a size fact with brewing consequences — These four words describe how big the pieces are. Size changes how fast a tea extracts and therefore how it must be brewed, which is a real and important difference — and it is not a quality ladder, however consistently it is sold as one.
• Orthodox and CTC are two industries, not two qualities — One process was designed to preserve the leaf and the differences between lots; the other was designed to produce a uniform, strong, fast-brewing product at scale. Comparing them on a single quality axis misses that they were built to different specifications.
• How the tea bag was invented, and what it changed — The charming origin story — a New York merchant’s silk sample pouches, accidentally brewed by customers — is unverified and postdates a filed patent by other people. What is certain is that the bag reorganised the entire tea industry around a leaf grade nobody would otherwise have made.
• From field to shelf: who handles tea on the way — Between the person who plucked a leaf and the person who drinks it there are usually six or seven other businesses, and each of them exists for a reason. Knowing what each one actually does explains most of what is otherwise puzzling about tea pricing and labelling.
• Commodity tea and speciality tea are two different industries — They share a plant and almost nothing else. Different unit sizes, different definitions of quality, different buyers, different risks and different reasons for existing — which is why advice drawn from one is so often wrong about the other.
• The bought-leaf factory, and what it does to a grower’s leverage — A factory that buys green leaf from surrounding farms is the hinge of smallholder tea. It is also, in most places, the only buyer a grower can physically reach before the leaf spoils — and that fact shapes the whole relationship.
• Yield, mechanisation and the labour economics behind them — Plucking is the largest recurring labour cost in tea and the hardest to mechanise without changing the product. Everything about how tea fields are laid out, pruned and harvested follows from that tension.
• The economics of teabags and loose leaf — The teabag is a packaging decision that reaches all the way back into the field. It changes which grades are worth making, how much material moves per cup, how long the product lasts and who can sell it.
• Reading a wet leaf backwards to the process — The spent leaf in the bottom of the pot is the most honest document a tea comes with. Almost every processing decision leaves a mark on it, and reading those marks is a skill that takes an afternoon to start and rewards a lifetime.
• CTC grade codes: BP, PF, PD, Dust and what the letters mean here — CTC tea has its own grading vocabulary that looks like the orthodox letter system and works on different principles. It describes granule size and density in a manufacture where every particle is small by design, and it is the code most of the world’s tea is actually sold under.