Assam Black Tea of the Brahmaputra Valley

Assam is a black tea named for the Indian state it comes from, in northeast India's Brahmaputra valley, made from the large-leaf variety Camellia sinensis² var. assamica. The cup it makes is malty, brisk, full-bodied, and deep amber.

Assam in one table, with each line's full account in the section that follows:

The plant: Camellia sinensis var. assamica

The tea plant comes in two principal varieties. One is Camellia sinensis var. sinensis, the small-leaved China variety. Assam is the other one. Camellia sinensis var. assamica is a broad-leaved variety native to the region, with dark green, glossy, fairly wide leaves and a tolerance for heat and heavy monsoon rain that the China plant does not have. Attempts to grow Chinese tea in Assam soil failed; the local plant did not. That breadth of leaf is what gives the tea its body, its color, and its malt.

This is the variety behind most robust black tea. The gardens that grew up around it in the nineteenth century turned a wild jungle tree into a major commercial tea, and most of the strong black teas you drink trace back to it. The plant's wild origins, its naming, and the chemistry behind its strength are documented in full in the Assamica guide.

Where it grows: the Brahmaputra valley tea-growing area

The Brahmaputra valley is Assam's tea-growing area: lowlands on either side of the river, on clay soil enriched by floodplain silt. The defining fact of the place is that it is low. The gardens sit at or near sea level, not up a mountain, and this is what separates Assam from a high-grown tea such as Darjeeling.

The valley is hot and very wet: the Tea Board of India puts the gardens at 45 to 60 metres of elevation, with 2,500 to 3,000 millimetres of rain a year and heavy rainfall from March to September. Heat and water on rich flat soil grow a great deal of tea, briskly. Assam is the single largest tea-growing region in the world¹, and the largest tea-producing state in India⁶, accounting for more than half the country's output. The estates and terroir are documented in the Estates guide.

History in brief

The wild plant was used long before it was named. The Singpho and Khamti peoples of upper Assam brewed the leaves of the native tea trees for generations before any European recorded it. The trader Robert Bruce is supposed to have seen the plant growing wild near Rangpur, in upper Assam, during a visit in 1823³. His brother, Charles Alexander Bruce, obtained plants and seeds from a Singpho chief, and the leaf was eventually identified as a tea distinct from the Chinese plant.

An invoice of eight chests of Assam tea was forwarded to London in 1838 and auctioned on 10 January 1839³. The trade grew fast: by 1888 Britain was importing more tea from India than from China⁴. Assam marked two hundred years since Bruce's encounter with the plant in 2023⁶. The full account, including the indigenous use, the colonial plantation system, and the workforce it created, is in the History guide.

How it is made: CTC and orthodox

All Assam is fully oxidised, which is what makes it a black tea. It is plucked, withered, rolled or cut, oxidised, and dried. The rolling step is what divides it, and it produces two different teas.

• Orthodox keeps the leaf as whole as possible. The withered leaf is rolled into twisted strips and oxidised, producing larger leaf particles, a more complex cup, and the golden-tipped grades a connoisseur looks for. A fine orthodox Assam is a serious single-origin tea, drunk straight.
• CTC stands for crush, tear, curl. The leaf is run through cylindrical rollers set with hundreds of sharp teeth that crush, tear, and curl it into small, hard pellets. An Assam invention of the 1930s, it brews fast, dark, and strong, which is exactly what a tea bag needs⁵, and around 95 percent of the world's black tea is now CTC.

The two methods are compared in detail in CTC vs. orthodox.

How it is graded

Orthodox Assam is sorted by leaf grade, the orange-pekoe system the British trade built up in India for sorting black tea. A grade describes the size and condition of the leaf, whole, broken, or fine, and how much young golden tip rides in it, not the flavour directly, though the two track each other. The letters climb from OP, plain whole leaf, up through TGFOP, the tippy high grade that is Assam's workhorse, to FTGFOP and above at the top of the orthodox range; CTC carries its own shorter codes by particle size instead. The full alphabet, read letter by letter, is set out in the Grading guide.

How it tastes

Malt is the word the trade uses for Assam. A good Assam tastes faintly of malt loaf or toasted grain, with a brisk, bright edge the tasters call briskness. The liquor is deep amber and full-bodied. The cup is built to carry milk: where many teas turn thin and grey under milk, Assam holds its color and its strength. How milk and Assam work together is covered in Milk and Assam.

The flushes

Assam is plucked in flushes, the seasonal rounds of new growth.

• First flush comes in late March, the spring growth. It is lighter and brisk.
• Second flush comes in early summer. It is the harvest that earns the top grade: fuller, maltier, sweeter, and dotted with golden tips.

The second flush is what the grading and tasting language is built around, and it is detailed in The second flush.

For getting it right in the cup, see the Brewing guide.