Tea belongs to the camellia family of plants. India is the world’s second largest producer after China and second largest consumer of tea, accounting for nearly 25-27 per cent of world tea production. India accounts for around 10-12 per cent of world tea exports. Further, certain varieties of tea are grown only in India and are in great demand across the world. Popular varieties of tea in India after Masala Chai are Black Tea, Green Tea, Irani Chai, Tandoori Chai, Amrut Tulya etc.
Tea production volume across India 2019 by state
Tea production in Assam was approximately 702 million kilograms in fiscal year 2019, the highest to any other region in the country. Over 1500 different varieties of teas that are categorized into three groups: black, green and oolong. Teas are grouped based on how much processing they go through and the amount of time they are in contact with oxygen.
Tea is harvested by hand and only some leaves are picked which are juicy and healthy. A few leaves, part of the stem and a tip are called ‘flush’. Flush is the basis of tea production. Flush with two or three leaves is called a ‘golden flush'. Flushes are collected with three, four and even five leaves.
Tea bush is a tropical and subtropical plant and thrives well in hot and humid climates. There is a very close relation between climate, the yield and the quality of tea. The ideal temperature for its growth is 20°-30°C and temperatures above 35°C and below 10°C are harmful for the bush.
Method of Cultivation:
Tea gardens are set up on the cleared hill slopes where shade trees are planted in advance. Seeds are sown in the germination beds and the saplings transplanted to the garden. The garden is regularly hoed and weeded so that tea bush grows without any hindrance. Use of manures and fertilisers is a common practice in the gardens. Oil cakes and green manures are widely used.
Pruning of the plant is an essential part of tea cultivation. It helps in maintaining the proper shape of tea bush to a height of about one metre with about the same diameter. The aim of pruning is to have new shoots bearing soft leaves in plenty and to facilitate the plucking of leaves by women labourers from the ground.
Tea cultivation does not have a long tradition in India as it started in the middle of the nineteenth century only, when the first tea plantations were established in Assam. However, tea cultivation has shown steady progress right from the beginning.
Process of Tea Manufacturing
- Plucking Tea leaves and flushes, which includes a terminal bud and two young leaves, are picked from Camellia sinensis bushes Collected twice a year during early spring and early summer or late spring.
- Picking is done by hand when a higher quality tea is needed, or where labour costs are not prohibitive.
- Withering/ Wilting The tea leaves begin to wilt soon after picking. Withering is used to remove excess water from the leaves and allows a very slight amount of oxidation.
- Disruption/ Rolling the tea leaves are bruised or torn in order to promote and quicken oxidation. The leaves may be slightly bruised on their edges by shaking and tossing in a bamboo tray or tumbling in baskets. More extensive leaf disruption can be done by machinery.
- Rotor vane Tea leaves are passed on to the Withering trough, Where it gets crushed and goes to the Rotor Vane .
- Leg-cut Triturator and other instruments used for crushing tea leaves.
- Rolling / Shaping The damp tea leaves are then rolled to be formed into wrinkled strips, by hand or using a rolling machine which causes the tea to wrap around itself. This rolling action also causes some of the sap, essential oils, and juices inside the leaves to ooze out, which further enhances the taste of the tea
- Oxidation/Fermentation For teas that require oxidation, the leaves are left on their own in a climate-controlled room where they turn progressively darker. This is accompanied by agitation in some cases. oxidation occurs during the manufacture of white, oolong, and black teas. Green and yellow teas are prevented from oxidizing by steaming, drying and/or frying techniques
- During the manufacture of tea, both spontaneous and controlled oxidation occurs Oxidation in tea manufacture officially begins during the withering stage as spontaneous oxidation then accelerates gradually during the subsequent steps necessary to transform fresh leaf into finished black tea
- Oxidation process is often incorrectly termed as ‘fermentation’ In traditional oxidation, sieved leaf is spread out in a thin layer (2-3 inches or 5-8 cm) on the floor of factory, on tables or perforated trays
- Several flavor compounds produced by reaction with sugars and amino acids Green Tea - no oxidation Yellow Tea -no oxidation White Tea slight, spontaneous oxidation occurs (8-15 per cent) Oolong Tea- partial oxidation Black Tea fully oxidised Puerh always fermented, not always oxidised
- Fermentation is important in manufacture Black tea The leaves must be exposed to bacteria (or have bacteria present inherently) in order for fermentation to occur exposure to oxygen during tea manufacture is often reduced or eliminated after the withering stage for fermentation
- Bacteria required to both initiate and maintain fermentation are potentially present during several aspects of its production: 1. On the surfaces of the leaf of the old- growth plants themselves 2. In the controlled environment of the tea production rooms in which the ‘Raw’ is temporarily stored
- Fixation / Kill-green is done to stop the tea leaf oxidation at a desired level. This process is accomplished by moderately heating tea leaves, thus deactivating their oxidative enzyme
- Drying Drying is done to ‘finish’ the tea for sale. This can be done by panning, sunning, air drying, or baking. The drying of the produced tea is responsible for many new flavour compounds particularly important in green teas
- Aging or Curing some teas required additional aging, secondary fermentation, or baking to reach their drinking potential
- Packaging . Packing is the process of preserving the product using the cheapest but most appropriate material taking into account the product properties. Before packing tea is passed under powerful magnets to prevent possible pieces of iron mixing with the tea and finally Packing.
Tea is the most affordable, simple and pleasant way to refresh, enhance natural immune mechanisms, preserve health and beauty. Each cup of tea is a perfectly balanced combination of vitamins, minerals, enzymes, biologically active substances that increase vitality and improve health.
With over 144 tea gardens, Dibrugarh has rightly earned the sobriquet as the 'Tea City of India'.