Tea is produced by harvesting the fresh shoots of the tea plant, an evergreen shrub or small tree, with dark green glossy leaves and small white flowers. In its natural state the tea plant could grow to five metres tall but in commercial plantations, it is kept to a height of about one metre due to ongoing harvesting. Tea plantations are expected to have a productive life of 50–100 years; and some tea trees in China are reported to be 700–1000 years old.
Tea is the second most consumed beverage in the world after water, with an estimated 18–20 billion cups of tea consumed every day. There are three main types of tea produced in the world—black, green and oolong. The difference in types is based to some extent on plant variety and most significantly on processing technique.
The tea plant belongs to the genus Camellia, as do the species of camellia commonly found in gardens. Black tea is produced primarily from the plant Camellia sinensis var. assamica, which is native to the Assam region of India, and its harvested leaves are fermented and dried, resulting in a black leaf. Green tea is produced mostly from Camellia sinensis var. sinensis, native to China, and its harvested leaves are steamed or roasted to prevent fermentation and then dried, resulting, in a green leaf. Oolong tea is also produced from Camellia sinensis var. sinensis but the harvested leaves are only partially fermented before drying. While three main types of tea are recognised, globally there are many geographical variations of the main tea plant varieties, and many cultural variations on procedures to make tea.
Global production of tea, averaged over three years to 2011, was 4.5 million tonnes. While there are not figures available on production for different types, general industry estimates are 72% is black tea, 25% is green and 3% is oolong.
In Australia, black tea is produced in northern Australia from plants descended from several sources of seed, most likely Camellia sinensis var. assamica. Existing plantings are based on suitable provenance stock rather than specific varieties. Japanese green tea is grown in the southern half of Australia from specific Japanese varieties of Camellia sinensis var. sinensis. These varieties are a smaller and slower growing plant, with smaller leaves and more cold tolerance than ‘black tea’ plants. Green tea varieties require a dormant period to produce the important first flush of growth in mid to late spring, and the plants have three to four flushes of active shoot growth per year. Black tea, grown in subtropical and tropical climates, grows and is harvested all year round.
The production of black tea in Australia started with tea plants from Sri Lanka being planted in tropical northern Queensland in the late 1880s. However consecutive natural disasters, labour shortages and finally a tidal wave, meant that the enterprise did not thrive. In the 1970s and 80s commercial interest in tea production expanded on the Atherton Tableland, and as at 2013, almost 90% of Australian black tea is produced in the region, with the remainder being produced in the Northern Rivers region of New South Wales.
Facts and figures
- Tea is the second most consumed drink in the world after water, with an estimated 18–20 billion cups of tea consumed every day
- As at 2011–12, Australia had over 500 hectares planted to plants for mainly black tea production, and about 6,000 tonnes of fresh leaf was harvested annually
- The leaf harvested from plants in northern Australia is used to make black tea
- As fresh tea leaves need to be correctly stored within 1.5 hours of harvesting and processed after 12 hours of correct storage, proximity to a processing facility is a key consideration for tea production
- Black tea has a stronger flavour, more caffeine and longer shelf life than green tea and was traded as compressed bricks
- Britain imported tea from China for over 200 years but in the 1830s native tea plants were discovered in the British colony of India and the British have controlled the world marketing of black tea since