Tea

Tea is a stimulating beverage commonly categorized with Coffee, Hot Chocolate, Energy Drinks, and Soft-Drinks,

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Tea is considered a stimulating beverage because it can contain anywhere between 15mg to 60+mg of caffeine depending on the type of tea. Tea is brewed from the tea plant, known as Camellia sinensis native to Southeast Asia. The top leaves and buds are the parts of the plant which are consumed in tea. Based on various methods of processing tea leaves, the four main teas produced are black tea, green tea, oolong tea, and white tea.


Classification

Kingdom
//Plantae// – Plants
Subkingdom
//Tracheobionta// – Vascular plants
Superdivision
//Spermatophyta// – Seed plants
Division
//Magnoliophyta// – Flowering plants
Class
//Magnoliopsida// – Dicotyledons
Subclass
//Dilleniidae//
Order
//Theales//
Family
//Theaceae// – Tea family
Genus
//Camellia// L. – camellia
Species
//Camellia// //sinensis// (L.) Kuntze – tea


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Family

Camellia sinensis, is a member of the Theaceae family, which includes 40 genera and 600 species of trees and shrubs. There are some characteristics common to plants in the Theaceae family. Their leaves are alternate, simple, and estipulate. Their large flowers are generally pink or white and have a strong scent.

The Camellia sinensis is an evergreen shrub, native to Southern Asia. Its flowers are whitish yellow, 2.5 - 4 cm in diameter, and have 7 or 8 petals. Its leaves range from 4-15 cm in length and 2-5 cm wide. When young, leaves are typically a lighter green and have short white hairs on the underside. When older the leaves develop and darker green color. Generally the leaves that are selected for harvest are the leaves at the top of the tree.



History

Various cultures have different beliefs of when tea was first discovered and cultivated. The Chinese date the discovery of tea back as early as 2737 B.C. However the dried tip of the leaves from the Camellia sinensis, or tea plant, native to areas around Tibet, India, China, and Burma, did not reach Europe until the 1400s. Tea reached Western Europe in 1610 when the Dutch introduced it to Holland. In the 1650s tea had reached England, leading to mass popularization in the West. The rate at which the British imported tea increased drastically and by 1780 they had imported 14 million pounds.

Soon after the Dutch introduced tea to England, the Dutch introduced tea to North America around 1650. Though at first only affordable by the wealthy due to high prices, by the mid-1700s tea soon became an acceptable habit for all colonists. With the growing demand for tea leaves in North America, the British East India Company, the official import company for tea in North America, fought with smugglers who were offering colonists lower prices for the same tea. Induced by the rising competition between the British East India Company and tea smugglers, Parliament passed the Tea Act of 1773. The Tea Act waved import taxation of tea, allowing the British East India Company to sell their tea at low enough prices to gain control of the tea market. Because the British East India Company was able to sell tea directly to the colonies due to the Tea Act, colonial merchants had trouble competing. The colonists, angered by the tax break that the British East India Company received from the Tea Act, responded by The Boston Tea Party, sparking the Revolutionary War between the colonists and Great Britain.

The Revolutionary War, with regards to the tea plant, resulted in many coffee drinkers in the United States, as a way of boycotting imports related to England. However in the 1900s iced tea became one of America’s favorite cold beverages. In 1904, the invention of the silk tea bag, in place of the former tins, led to increased consumption of tea as tea drinkers realized that boiling tea in the silk bags was an easier way to brew tea. Over the past 100 years, the tea bag has become the most popular and current way that tea drinkers consume their tea.


Geography


teamap.jpgThe tea plant is native to Southeast Asia, near Tibet, India, China, and Myanmar (see map for specific popular regions). It needs mild temperatures, very wet summers, and dry winters in order to grow best. Southeast Asia has tropical and subtropical climate, where there is sufficient rainfall and little chance of frost, making a proper environment for successful tea plant growth. However, with few alterations tea has been successfully grown throughout the world. For instance, for areas where frost occurs, tea growers must be sure to protect the plant from frost seasons at the beginning of winter. In the summer, tea plants must be given extra water if the natural climate of the region does not provide sufficient rainfall. Tea plants have even been successfully grown indoors when temperatures have been kept mild.
(For additional information see history section and map of Major Tea Growing Regions)



Human Use and Domestication


Camellia sinensis if uncultivated by humans, generally grows to a height of 24-34 feet high. Because the best leaves for making tea are found at the top of the tea plant, humans generally do not allow the plant to grow more than 4 feet tall. Similarly for cultivating purposes, humans trim the top of the plant to have a flat top, which results in the plant producing more shoots with new buds and leaves. Once the tea leaves have been harvested, they can be treated in four different ways: to produce black tea, green tea, white tea, or oolong tea.

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Sample of Black Tea Leaves
Black tea, or fermented tea, has the most detailed production process. After tea leaves are gathered, the leaves are dried with hot air for 12-24 hours, by a process called withering, allowing water to evaporate from the leaves. After withering, the leaves are rolled and broken up. These broken apart leaves are then fermented in a cool, humid, room which allows the leaves to turn to a copper color. To stop fermentation, the leaves are then put in hot air chambers to dry them out once again. The result is black leaves used for brewing black tea.


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Sample of Green Tea Leaves




Green tea is processed more simply than black tea. For green tea, leaves are steamed, rolled, and then dried.



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Oolong Tea Leaves



Oolong tea is produced in the same way as black tea, except the leaves are not allowed to wither and ferment as
long. Also, different types of oolong tea are made based on separating the different sized leaves after fermentation.

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White Tea Leaves





White tea is made from a variation of the tea plant that has small white hairs on its leaves. When the leaves are young, they are harvested, withered, and dried. Because the leaves are silvery-white, the resulting beverages is pale yellow.





Short Term Uses and Benefits for Tea


Tea drinkers often rave about how healthy drinking tea on a regular basis is for long term health reasons. It is true that drinking tea, especially green tea, is a way to reduce the likelihood of getting cancer, to reduce the level of LDL (bad cholesterol) in our bodies, as well as generally boost the body’s immune system. Though it has been shown that consuming tea has many long term benefits, the general public seems to overlook the short term, immediate, uses and benefits of tea.

One way in which tea can be used for short term health is by applying tea to relieve pain on skin. By soaking a tea bag and placing it on a razor burn, the tea can relieve the burning sensation. Similarly if you have a sore arm, after getting a shot from the doctors, applying a wet tea bag will soothe the hurt region as the tannic acid from the tea touches the region. Need a way to soothe your toothache before your dentist appointment? Drink some tea and swish the tea around before swallowing to reduce the pain of toothaches. Also, by dabbing brewed tea on a poison ivy rash, you can relieve the itchiness as the tea will dry out the rash. In all these ways tea can act as an instant pain reliever by applying it directly on skin.

Interestingly enough tea can be used for beauty purposes as well. Not only can you use tea as hair conditioner by rinsing hair with warm unsweetened tea, but also you can use tea to color hair. By adding 3 tea bags to 1 cup of boiling water, adding 1 tablespoon of rosemary and sage and allowing it to stand overnight, you will have concocted a mixture that can restore dark hair from gray hair when applied to wet hair. Popular to beach-goers, tea can actually be used to create a homemade tanning solution that is much healthier than using a tanning bed. By brewing 2 cups of strong black tea, allowing it to cool, and spraying it directly on skin, one can get their desired tan color according to how much tea is applied to their skin.

Tea can also be used to do household chores. Brewed tea, once cooled, can be soaked in a rag and used to clean wooden surfaces. Also by soaking white lace of garments in a tea bath consisting of 3 tea bags per 2 cups of water, the lace or garment will obtain a darker shade depending on how long it is soaked for. Brewed tea can be used to shine mirrors or glass as well, by simply soaking a cloth and applying to the surface.


References
[1]Luna I, Ochoterena H (2004) ‘Phylogenetic relationships of the genera of Theaceae based on morphology.’ Cladistics Vol. 20 223-270
[2]http://www.botany.hawaii.edu/faculty/carr/the.htm
[3]http://www.learn-about-tea.com/camellia-sinensis.html
[4]http://www.plantcultures.org/plants/tea_grow_it.html
[5]
http://www.rd.com/advice-and-know-how/extraordinary-uses-for-tea/article24030.html
[6]Leventin, Estelle and Karen McMahon. Plants and Society Fifth Edition. McGraw-Hill, NY 2008