Assam is a black tea grown in the Brahmaputra valley of northeast India, made from the large-leaf variety Camellia sinensis var. assamica. The cup it makes is malty, brisk, full-bodied, and deep coppery red, strong enough to take milk without thinning out. It is one of the two principal varieties of the tea plant, the broad-leaved one behind most robust black tea, the base of most English and Irish breakfast blends, and the strength in a great many tea bags. This is the Authority's record of what Assam is, certified by weight and measure: the plant, the place, how it is made, how it is graded, how it tastes, and where it ends up. The deeper accounts sit in the linked references below.

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.

Where it grows: the Brahmaputra valley

Assam tea grows in the lowlands of the Brahmaputra valley, 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. Where a high garden trades yield for delicacy, the hot, wet valley trades delicacy for strength and volume.

The valley is hot and very wet: the Tea Board of India puts the gardens at 45 to 60 metres of elevation (about 150 to 200 feet), with 2,500 to 3,000 millimetres of rain a year (roughly 100 to 120 inches) 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 world by production, and the largest tea-producing state in India, 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 1823; 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 1839. The trade grew fast: by 1888 Britain was importing more tea from India than from China. Assam marked two hundred years since Bruce's encounter with the plant in 2023. 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 fork in the road is the rolling step, 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 needs, and CTC now makes up the great majority of tea produced.

Same plant, same valley, two products. The orthodox tea is the one you drink for itself; the CTC tea is the engine of the everyday brew. 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, and it is the right one. A good Assam tastes faintly of malt loaf or toasted grain, with a brisk, bright edge the tasters call briskness. The liquor is deep coppery red 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. That is the property this office certifies before any other, and it is why Assam is the standard breakfast tea. 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 prized harvest: fuller, maltier, sweeter, and dotted with golden tips. When a tin says "second flush Assam," it is naming the better tea.

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

Where it ends up

Most Assam never reaches you under its own name. It is the backbone of English Breakfast and Irish Breakfast blends, the strength in a builder's brew, and the brisk base in a great many tea bags. Irish Breakfast in particular leans on small-leaf Assam for its punch. Drunk straight, a fine orthodox Assam is a single-origin tea worth real attention. Blended, it is the reliable engine of the morning. Either way the job is the same: strength, on time, every day. For getting it right in the cup, see the Brewing guide.