How Black Tea Is Made: CTC and Orthodox
The canonical reference on the two ways black tea is manufactured, crush-tear-curl and orthodox, and why that one factory decision has sorted the world's tea economies into different positions in the market.
Black tea is manufactured in one of two ways, and almost every black tea sold anywhere is the product of one of them. The two methods are CTC, short for crush, tear, curl, and orthodox. Both begin with withered leaf from the same plant, Camellia sinensis, and both finish as a fully oxidized black tea. What separates them is how the leaf is broken on the way there, and that single mechanical choice decides the size of the particle, the speed and strength of the brew, the amount of human labour spent per kilo, and, at national scale, whether a country sells tea under its own name or ships it anonymously into someone else's blend.
This is specifically a black-tea distinction. It describes how black tea is made and graded, and it does not map onto green, oolong, white, yellow, or dark (pu-erh) tea, which are made by other methods entirely. Where that boundary matters, this guide draws it plainly below.
The two methods, side by side
The cleanest way to hold the distinction is by what happens to the leaf cell. CTC ruptures it completely; orthodox mostly keeps it intact. Everything else follows from that.
| Trait | CTC (crush, tear, curl) | Orthodox |
|---|---|---|
| Core action | Leaf shredded between toothed rollers | Leaf rolled and twisted, bruised but not shredded |
| Leaf cell | Fully ruptured | Largely preserved |
| Machinery | Pairs of grooved, toothed cylindrical rollers | Gentler rollers plus staged, supervised handling |
| Human input | Minimal once leaf is fed in | Hands-on judgement at every stage |
| Throughput | A full batch in roughly two hours | Slow, stage by stage |
| Labour per kilo | Low | High |
| Output form | Small, hard, uniform granules | Whole and broken leaf of varied size |
| In the cup | Strong, brisk, fast-brewing, deep colour, astringent | Slower to brew, more layered and complex |
| Typical end use | Tea bags, blends, milk tea | Loose-leaf, single-origin, premium grades |
Crush, tear, curl
CTC industrialized black tea. Withered leaf is passed through pairs of cylindrical rollers whose surfaces carry hundreds of sharp teeth, set in circumferential and helical grooves. The design was adapted from the smooth rollers of a flour mill, re-cut so that instead of grinding grain they crush, tear, and curl tea leaf into small, hard, uniform pellets. Because the leaf cells are completely ruptured, the enzymes and compounds that drive oxidation are released fast, and a full batch moves through in about two hours with little hands-on intervention once the leaf is fed in.
CTC was invented in 1930-1931 by Sir William McKercher at the Amgoorie Tea Garden in Assam, according to Goodricke, the estate's own present-day owner, which still counts Amgoorie among its top CTC gardens, corroborated by the Halmari Tea Estate's own account of the invention, a separate working Assam garden. A follow-on preconditioning machine, the rotorvane, arrived some decades later and fed the main rollers a more consistent particle. From there CTC spread quickly through India and across Africa, mainly from the 1950s through the 1970s, carried by demand for a broken-leaf tea that packed efficiently into tea bags and brewed a strong cup quickly.
That last point is the commercial heart of it. A tea bag needs a small, fast-extracting particle, and CTC produces exactly that, at volume, cheaply, and with a consistency a blender can rely on season to season.
Orthodox manufacture
Orthodox is the older method, and it predates CTC by more than sixty years. It runs the same broad sequence, wither, roll, oxidate, dry, but at each stage the leaf is handled gently and deliberately. The rolling bruises and twists the leaf rather than shredding it, so much of the leaf's own structure survives into the finished tea. Every stage is comparatively slow and takes individualized judgement from trained processors: how long to wither, how hard to roll, how far to carry the oxidation. That judgement is the reason orthodox tea is far more labour- and time-intensive per kilo than CTC, a cost structure explored further in labour in the gardens.
Orthodox manufacture also carries the industry's founding history outside India. Sri Lanka's tea industry began in 1867, when the Scottish planter James Taylor, born in 1835 and in Ceylon since 1852, planted the island's first commercial tea, about nineteen acres, at the Loolecondera estate near Kandy, using seed brought from Assam, according to the Ceylon Tea Museum. Taylor first hand-processed the leaf on his own bungalow veranda, using clay stoves and charcoal fires for oxidation, having consulted experienced Assam planters on technique. In 1872 he built a proper factory on the estate, where, per the museum's account, "the first roller ever made in Ceylon" was put to work, an early landmark in orthodox manufacture's own mechanical history. His first shipment to the London auction, in the early 1870s, was a modest twenty-three pounds of tea in two small packs; by 1873 his tea was already fetching strong London prices. He stayed in Ceylon until his death in 1892.
What each method does to the cup
The mechanical difference resolves into a difference you can taste. CTC's complete cell rupture yields a strong, brisk, fast-brewing liquor with a deep colour and a distinctly astringent edge. That astringency is a feature, not a fault: it holds up to milk and sugar, which is why CTC dominates the tea-bag trade and much of the milk-tea market. Orthodox's preserved leaf structure brews more slowly but delivers a more complex liquor, the reason loose-leaf and specialty buyers pay more for it. The tradeoff is legible in one line. CTC trades complexity for speed and cost; orthodox trades speed and cost for complexity.
The finished tea is then sorted by particle size into named grades. That grade code is its own subject, documented in full in a tea's grade is a size code, not a quality score; the short version is that the letters (OP, BOP, BP1, PF1, Dust1 and the rest) describe leaf size and style, not merit.
Why the country map looks the way it does
The CTC-versus-orthodox split is not just a factory-floor choice. Made at national scale, over decades, it has sorted the major producers into durable, structurally different positions in the world tea economy. Country-level production shares are laid out in who grows it; the manufacturing logic behind them is this.
India is predominantly a CTC country. In June 2025, for instance, Tea Board of India data put CTC at 117.84 million kilograms of that month's output against 13.82 million kilograms of orthodox and 1.84 million kilograms of green, as reported by Business Standard, or roughly 88 percent CTC by this publication's own arithmetic on those figures, a ratio that holds broadly from month to month. Production is concentrated in the high-volume Assam and Dooars-Terai plains. Its notable orthodox exceptions are the hill teas of Darjeeling and the Nilgiris. India's CTC bias is not explained by cost alone. India is itself an overwhelmingly milk-tea-drinking market, where chai is boiled with milk and sugar, and CTC's fast, strong, high-astringency liquor stands up to milk far better than a delicate orthodox brew does. CTC won India partly because it suits how the tea-growing world's largest population actually drinks tea. More region detail sits in the India guide.
Kenya is the sharper case. It is overwhelmingly a CTC producer and the world's largest exporter of black tea by volume, yet almost all of that output is sold as an anonymous bulk commodity that feeds other countries' blends and tea bags, rarely marketed under Kenya's own name. CTC and black tea have accounted for roughly 99 percent of Kenyan production and shipments, with orthodox and specialty tea only about 1 percent in the mid-2020s, per Ecofin Agency's reporting on Kenya's own targets. Kenya has decided this is a problem worth legislating. Its Tea Act, 2020, requires that at least 40 percent of the country's tea be value-added, meaning processed beyond raw bulk CTC, by 2028, climbing by roughly five percentage points a year; in 2024, value-added exports were still only about 5 percent of the total, some 28.9 million kilograms (roughly 64 million pounds), according to The Star's report on the KTDA target. The Kenya Tea Development Agency, through its Ketepa subsidiary and ChaiGold brand, is the main vehicle for that target; KTDA's group chief executive, Wilson Muthaura, has framed the strategy as working "to deepen footprints in the international market by increasing tea value addition," as reported by History of Ceylon Tea. Separately, under Kenya's Bottom-Up Economic Transformation Agenda, the country has targeted a roughly tenfold expansion of specialty and orthodox capacity, from about 15,000 to 200,000 tonnes (about 16,500 to 220,000 US tons), by 2030. Why a country would legislate against making more of what it is already best at is a value-capture question, taken up in what a certification label actually pays.
Sri Lanka is Kenya's mirror image. Close to 93 percent of Ceylon tea is made by artisanal, orthodox methods, per Sri Lanka's own Export Development Board, the inverse of the Kenyan and Indian ratios. Sri Lanka built the internationally recognized "Ceylon Tea" identity around that orthodox, high-grown, loose-leaf tea, capturing value and name at origin rather than exporting a blend-ready commodity that vanishes into someone else's brand. That is a structural reason Sri Lankan tea has historically fetched stronger export prices than Kenyan tea, even though Kenya exports far more tea by volume. The Sri Lanka guide carries the regional detail; the broader pricing mechanics are in the price of tea.
Process is not a permanent quality verdict
It is tempting to compress all of this into "CTC is cheap, orthodox is premium," and that shorthand overstates a real pattern into an absolute rule. The method a garden chooses is not a fixed quality ruling on its leaf; within either family, the specific grade and lot still set the price a buyer will pay, which is why the size-code grade families documented in a tea's grade is a size code, not a quality score matter as much as the CTC-versus-orthodox choice itself. The process sets what is possible; the grade and the lot decide what a given kilo actually earns.
A boundary: this is a black-tea distinction
The CTC-versus-orthodox split describes how black tea, specifically, is manufactured, and it does not generalize to countries whose tea economy is not built on black tea. China, the world's largest producer by volume, makes mostly green, oolong, white, yellow, and dark (pu-erh) tea by entirely different methods, and grades that tea by a separate sensory system rather than the size-based grade alphabet that CTC and orthodox black teas share. That sensory system is documented in this site's grading reference; the point to carry away is that a discussion of CTC and orthodox is, by definition, a discussion about black tea and the countries that live on it.
Related on this site
This guide deepens one branch of how the trade works. For the size-code grades that sort the finished tea, see a tea's grade is a size code, not a quality score. For who makes what, see who grows it, the India guide, and the Sri Lanka guide. For the economics of price and value capture, see the price of tea, labour in the gardens, and what a certification label actually pays.