In the early 19th century, English colonials systematically established large plantations on the slopes of the Himalayas around Darjeeling in the northern part of India . The strong mountain sun and low night-time temperatures caused the leaves of the tea bushes to grow particularly slowly, resulting in the distinctive, mild aroma of this tea. Darjeeling tea ranks among the finest and most expensive varieties in the world.

Darjeeling grows at altitudes ranging from 600 to 2000 metres. The cool moist climate, the soil, the rainfall and the sloping terrain, all combine to give Darjeeling its unique 'Muscatel' flavour and exquisite bouquet. In general, quality of Darjeeling tea is characterized by the presence of higher level of monoterpenes and differs significantly with Assam and south Indian teas on this parameter. The later teas are, however, rich in non-terpenoids. A quantitative change in the level of terpenoids and non-terpenoids bring about the changes in the quantity of flavour of these teas. Characteristic "muscatel flavour" of Darjeeling teas are reported to be associated mainly with 2, 6-dimethyl-3, 7-octadiene-2, 6-diol and 3, 7- dimethyl-1, 5, 7-octatriene-3-ol.

Darjeeling tea is a protected brand name, defined by the Tea Board of India as : ‘tea which has been cultivated, grown, produced, manufactured and processed in tea gardens in the hilly areas of Sadar Sub-Division, only hilly areas of Kalimpong Sub-Division comprising of Samabeong Tea Estate, Ambiok Tea Estate, Mission Hill Tea Estate and Kumai Tea Estate and Kurseong Sub-Division excluding the areas in jurisdiction list 20,21,23,24,29,31 and 33 comprising Subtiguri (Siliguri) Sub-Division of New Chumta Tea Estate, Simulbari and Marionbari Tea Estate of Kurseong Police Station in Kurseong Sub-Division of the District of Darjeeling in the State of West Bengal, India '

Tea plantation in Darjeeling (Source)