Tea is the second most popular beverage in the world (the most popular is water). It is made by steeping processed leaves, buds or twigs of the tea bush Camellia sinensis in hot water for a few minutes. The processing can include oxidation (fermentation), heating, drying and the addition of other herbs, flowers, spices and fruits. There are four types of true tea: black tea, oolong tea, green tea, and white tea. Tea is a natural source of caffeine, theophylline, and antioxidants, although it has almost no fat, carbohydrates, or protein. It has a cooling, slightly bitter and astringent taste. Iced Tea has been popular in North America since the 1904 St. Louis World's Fair.

Tea is one of the most popular beverages in the world. About 3.2 million tonnes of tea were produced worldwide in 2004. India, China, Sri Lanka and Kenya (in descending order) are the most prolific producers of tea leaves.

The term herbal tea usually refers to infusions of fruit or herbs such as rosehip tea, chamomile tea and Jiaogulan that contain no tea leaves. Alternative terms for herbal tea that avoid the misleading word "tea" are tisane and herbal infusion. This article is concerned exclusively with preparations and uses of the tea plant Camellia sinensis.

Cultivation

 

Tea gardens in Munnar, Kerala, India

 

A Malaysian tea plantation

In the wild, the tea plant Camellia sinensis may grow from 5 to 15 m, and sometimes even to 30 m. The natural distribution consists of the foothills of the Himalayas, from northeast India to southwest China, areas with subtropical monsoon climates with wet and hot summers and relatively cold and dry winters. Today, it is cultivated in many tropical and subtropical regions. In tropical regions, the best conditions are at higher altitudes. Important tea producing regions are mainland China, Taiwan, India, Kenya, Sri Lanka, Japan, Indonesia, Nepal and Bangladesh. (In the tea trade, Sri Lanka and Taiwan are still referred to by their former names of Ceylon and Formosa, respectively.) Recently the Tregothnan Estate in Cornwall, England has started growing tea. Tea has also been cultivated in the United States since 1744. 

Cultivated tea shrubs are usually trimmed to below 2 m (six feet) to stimulate the growth of leaves and to ease plucking. Many insects, including green leafhoppers, mites, caterpillars, and termites, are natural enemies of tea plants.

Several varieties of Camellia sinensis are used for tea making, among them the Assam, China, Hong Kong and Cambodian varieties that differ in flavour, preferred climate and soil, and growing habit (some are shrubs, some trees).

 

World tea production by country in 2004, according to Food and Agriculture Organization estimates.

Processing and classification

The four types of tea are distinguished by their processing. Leaves of Camellia sinensis, if not dried quickly after picking, soon begin to wilt and oxidize. This process resembles the malting of barley, in that starch is converted into sugars; the leaves turn progressively darker, as chlorophyll breaks down and tannins are released. The next step in processing is to stop the oxidation process at a predetermined stage by removing the water from the leaves via heating.

The term fermentation was used (probably by wine fanciers) to describe this process, and has stuck, even though no true fermentation happens (i.e. the process is not driven by microbes and produces no ethanol). Without careful moisture and temperature control, however, fungi will grow on tea. The fungi cause real fermentation which will contaminate the tea with toxic and carcinogenic substances, so that the tea must be discarded.

Tea is traditionally classified based on the degree or period of fermentation (oxidation) the leaves have undergone:

White tea 

Young leaves (new growth buds) that have undergone no oxidation; the buds may be shielded from sunlight to prevent formation of chlorophyll. White tea is produced in lesser quantities than most of the other styles, and can be correspondingly more expensive than tea from the same plant processed by other methods. It is also less well-known in countries outside of China, though this is changing with the introduction of white tea in bagged form.

Green tea

The oxidation process is stopped after a minimal amount of oxidation by application of heat; either with steam, a traditional Japanese method; or by dry cooking in hot pans, the traditional Chinese method. Tea leaves may be left to dry as separate leaves or rolled into small pellets to make gun-powder tea. The latter process is time-consuming and is typically done only with pekoes of higher quality. The tea is processed within one to two days of harvesting.

Oolong

Oxidation is stopped somewhere between the standards for green tea and black tea. The oxidation process will take two to three days.

Black tea/Red tea

The tea leaves are allowed to completely oxidize. Black tea is the most common form of tea in southern Asia (India, Sri Lanka, Bangladesh, Pakistan etc) and in the last century many African countries including Kenya, Burundi, Rwanda, Malawi and Zimbabwe. The literal translation of the Chinese word is red tea, which may be used by some tea-lovers. The Chinese call it red tea because the actual tea liquid is red. Westerners call it black tea because the tea leaves used to brew it are usually black. However, red tea may also refer to rooibos, an increasingly popular South African tisane. The oxidation process will take around two weeks and up to one month. Black tea is further classified as either orthodox or CTC (Crush, Tear, Curl, a production method developed about 1932). Unblended black teas are also identified by the estate they come from, their year and the flush (first, second or autumn). Orthodox and CTC teas are further graded according to the post-production leaf quality by the Orange Pekoe system.

Pu-erh

(also known as Póu léi (Polee) in Cantonese), Two forms of pu-erh teas are available, "raw"  and "cooked" . "Raw" or "green" pu-erh may be consumed young or aged to further mature. During the aging process, the tea undergoes a second, microbial fermentation. "Cooked" pu-erh is made from green pu-erh leaf that has been artificially oxidized to approximate the flavour of the natural aging process. This is done through a controlled process similar to composting, where both the moisture and temperature of the tea are carefully monitored. Both types of pu-erh tea are usually compressed into various shapes including bricks, discs, bowls, or mushrooms. Compression occurs to start the second oxidation/fermentation process, as only compressed forms of pu-erh will age. While most teas are consumed within a year of production, pu-erh can be aged for many years to improve its flavour, up to 30 to 50 years for raw pu-erh and 10 to 15 years for cooked pu-erh, although experts and aficionados disagree about what the optimal age is to stop the aging process. Most often, pu-erh is steeped for up to five minutes in boiling water. Additionally, Some Tibetans use pu-erh as a caloric food, boiled with yak butter, sugar and salt to make yak butter tea. Teas that undergo a second oxidation, such as pu-erh and liu bao, are collectively referred to as Black tea  in Chinese. This is not to be confused with the English term Black tea, which is known in Chinese as Red Tea .

Yellow tea

Either used as a name of high-quality tea served at the Imperial court, or of special tea processed similarly to green tea, but with a slower drying phase.

Kukicha

Also called winter tea, kukicha is made from twigs and old leaves pruned from the tea plant during its dormant season and dry-roasted over a fire. It is popular as a health food in Japan and in macrobiotic diets.

Genmaicha

literally "brown rice tea" in Japanese, a green tea blended with dry-roasted brown rice (sometimes including popped rice), very popular in Japan but also drunk in China.

Flower Tea 

Teas processed or brewed with flowers; typically, each flower goes with a specific category of tea, such as green or red tea. The most famous flower tea is jasmine tea  H­eung Pín in Cantonese, Hua Chá, simply flower tea, in Mandarin), a green or oolong tea scented (or brewed) with jasmine flowers. Rose, lotus, lychee, and chrysanthemum are also popular flowers.

Da Hong Pao tea an Oolong tea

Fuding Bai Hao Yinzhen tea, a white tea

Green Pu-erh tuo cha, a type of compressed raw pu-erh

Huoshan Huangya tea a Yellow tea

Blending and additives

 

Tea weighing station north of Batumi, before 1915

Almost all teas in tea-bags and most other teas sold in England are blends. Blending may occur at the level of tea-planting area (e.g., Assam), or teas from many areas may be blended. The aim of blending is a stable taste over different years, and a better price. More expensive, better tasting tea may cover the inferior taste of cheaper tea.

There are various teas which have additives and/or different processing than "pure" varieties. Tea is able to easily receive any aroma, which may cause problems in processing, transportation or storage of tea, but can be also advantageously used to prepare scented teas.

Content

• Catechins, which are antioxidants. In fresh tea leaf, catechins can be up to 30% of the dry weight. Catechins are highest in concentration in white and green teas; black tea has substantially less due to its oxidative preparation.
• Caffeine, a stimulant. Tea averages 3% of dry weight.  A cup of prepared tea typically has about 40 mg of caffeine.
• Theophylline, a stimulant related to caffeine. Present in very small amounts.
• Theobromine, a stimulant related to caffeine. Present in very small amounts.

Origin and early history in Asia

The cradle of the tea plant is a region that encompasses eastern and southern China, northern Myanmar, and the Assam state of India. Spontaneous (wild) growth of the assamica variant is observed in area ranging from Chinese province Yunnan to the northern part of Myanmar and Assam region of India. The variant sinensis grows naturally in eastern and southeastern regions of China. Recent studies and occurrence of hybrids of the two types in wider area extending over mentioned regions suggest the place of origin of tea is in an area consisting of the northern part of Myanmar and the Yunnan and Sichuan provinces of China.

Origins of human use of tea are described in several myths, but it is unknown as to where tea was first created as a drink.

Creation myths

In one popular Chinese legend, Shennong, the legendary Emperor of China, inventor of agriculture and Chinese medicine, was on a journey about five thousand years ago. The Emperor, known for his wisdom in the ways of science, believed that the safest way to drink water was by first boiling it. One day he noticed some leaves had fallen into his boiling water. The ever inquisitive and curious monarch took a sip of the brew and was pleasantly surprised by its flavour and its restorative properties. Variant of the legend tells that the emperor tried medical properties of various herbs on himself, some of them poisonous, and found tea works as an antidote. Shennong is also mentioned in Lu Yu's Cha Jing, famous early work on the subject.

A Chinese legend, which spread along with Buddhism, Bodhidharma is credited with discovery of tea. Bodhidharma, a semi-legendary Buddhist monk, founder of the Chan school of Buddhism, journeyed to China. He became angered because he was falling asleep during meditation, so he cut off his eyelids. Tea bushes sprung from the spot where his eyelids hit the ground.  Sometimes, the second story is retold with Gautama Buddha in place of Bodhidharma In another variant of the first mentioned myth, Gautama Buddha discovered tea when some leaves had fallen into boiling water.

China

Whether or not these legends have any basis in fact, tea has played a significant role in Asian culture for centuries as a staple beverage, a curative, and a symbol of status. It is not surprising its discovery is ascribed to religious or royal origins. The fact is that the Chinese have enjoyed tea for centuries. Scholars hailed the brew as a cure for a variety of ailments, the nobility considered the consumption of good tea as a mark of their status and the common people simply enjoyed its flavour.

While historically the origin of tea as a medicinal herb useful for staying awake is unclear, China is considered the birthplace of tea drinking with recorded tea use in its history to at least 1000 BC. The Han Dynasty used tea as medicine. The use of tea as a beverage drunk for pleasure on social occasions dates from the Tang Dynasty or earlier.

 

Lu Yu's statue in Xi'an.

The Tang Dynasty writer Lu Yu's (729-804) Cha Jing  is an early work on the subject. (See also Tea Classics) According to Cha Jing written around 760, tea drinking was widespread. The book describes how tea plants were grown, the leaves processed, and tea prepared as a beverage. It also describes how tea was evaluated. The book even discusses where the best tea leaves were produced.

At this time in tea's history, the nature of the beverage and style of tea preparation were quite different from the way we experience tea today. Tea leaves were processed into cakes. The dried teacake, generally called brick tea was ground in a stone mortar. Hot water was added to the powdered teacake, or the powdered teacake was boiled in earthenware kettles then consumed as a hot beverage.

A form of compressed tea referred to as white tea was being produced as far back as the Tang Dynasty (618-907 A.D.). This special white tea of Tang was picked in early spring when the new growths of tea bushes that resemble silver needles were abundant. These "first flushes" were used as the raw material to make the compressed tea.

Advent of steaming and powder tea

During the Song Dynasty (960-1279), production and preparation of all tea changed. The tea of Song included many loose-leaf styles (to preserve the delicate character favoured by the court society), but a new powdered form of tea emerged. Tea leaves were picked and quickly steamed to preserve their colour and fresh character. After steaming, the leaves were dried. The finished tea was then ground into fine powders that were whisked in wide bowls. The resulting beverage was highly regarded for its deep emerald or iridescent white appearance and its rejuvenating and healthy energy. Drinking tea was considered stylish among government officers and intellectuals during the Southern Song period in China (12th to 13th centuries). They would read poetry, write calligraphy, paint, and discuss philosophy, while enjoying tea. Sometimes they would hold tea competitions where teas and tea instruments were judged. When Song Dynasty emperor Hui Zhong proclaimed white tea to be the culmination of all that is elegant, he set in motion the evolution of an enchanting variety.

This Song style of tea preparation incorporated powdered tea and ceramic ware in a ceremonial aesthetic known as the Song tea ceremony. Japanese monks traveling to China at this time had learned the Song preparation and brought it home with them. Although it later became extinct in China, this Song style of tea evolved into the Japanese tea ceremony, which endures today.

Many forms of white tea were made in the Song Dynasty due to the discerning tastes of the court society. Hui Zhong, who ruled China from 1101-1125, referred to white tea as the best type of tea, and he has been credited with the development of many white teas in the Song Dynasty, including "Palace Jade Sprout" and "Silver Silk Water Sprout".

Producing white teas was extremely labour-intensive. First, tea was picked from selected varietals of cultivated bushes or wild tea trees in early spring. The tea was immediately steamed, and the buds were then selected and stripped of their outer, unopened leaf. Only the delicate interior of the bud was reserved to be rinsed with spring water and dried. This process produced white teas that were paper thin and small.

Once processed, the finished tea was distributed and often given as a tribute to the Song court in loose form. It was then ground to a fine, silvery-white powder that was whisked in the wide ceramic bowls used in the Song tea ceremony. These white powder teas were also used in the famous whisked tea competitions of that era.

Roasting and brewing

 

Tea roasting

Steaming tea leaves was the primary process used for centuries in the preparation of tea. After the transition from compressed tea to the powdered form, the production of tea for trade and distribution changed once again. The Chinese learned to process tea in a different way in the mid-13th century. Tea leaves were roasted and then crumbled rather than steamed. This is the origin of today's loose teas and the practice of brewed tea.

In 1391, the Ming court issued a decree that only loose tea would be accepted as a "tribute". As a result, loose tea production increased and processing techniques advanced. Soon, most tea was distributed in full-leaf, loose form and steeped in earthenware vessels.

Oxidization (often mistakenly called fermentation)

Tea "fermentation" is not related to yeast fermentation. It is actually the oxidization of the tea leaves. In 17th century China numerous advances were made in tea production. In the southern part of China, tea leaves were sun dried then half fermented, producing Black Dragon teas or Oolongs. However, this method was not common in the rest of China.

Korea

The first historical record documenting the offering of tea to an ancestral god describes a rite in the year 661 in which a tea offering was made to the spirit of King Suro, the founder of the Geumgwan Gaya Kingdom (42-562).

Records from the Goryeo Dynasty (918-1392) show that tea offerings were made in Buddhist temples to the spirits of revered monks.

During the Joseon Dynasty (1392-1910), the royal Yi family and the aristocracy used tea for simple rites, the "Day Tea Rite" was a common daytime ceremony, whereas the "Special Tea Rite" was reserved for specific occasions. These terms are not found in other countries. Toward the end of the Joseon Dynasty, commoners joined the trend and used tea for ancestral rites, following the Chinese example based on Zhu Xi's text formalities of Family.

Stoneware was common, ceramic more frequent, mostly made in provincial kilns, with porcelain rare, imperial porcelain with dragons the rarest.

Historically the appearance of the bowls and cups is naturalistic, with a division according to religious influence. Celadon or jade green, "punchong", or bronze-like weathered patinas for Buddhist tea rituals; the purest of white with faint designs in porcelain for Confucian tea rituals; and coarser porcelains and ash-stone glazes for animist tea rituals, or for export to Japan where they were known as "gohan chawan". An aesthetic of rough surface texture from a clay and sand mix with a thin glazing were particularly prized and copied. The randomness of this creation was said to provide a "now moment of reality" treasured by tea masters.

Unlike the Chinese tradition, no Korean tea vessels used in the ceremony are tested for a fine musical note. Judgment instead is based on naturalness in form, emotion, and colouring.

The earliest kinds of tea used in tea ceremonies were heavily pressed cakes of black tea, the equivalent of aged pu-erh tea still popular in China. Vintages of tea were respected, and tea of great age imported from China had a certain popularity at court. However, importation of tea plants by Buddhist monks brought a more delicate series of teas into Korea, and the tea ceremony.

While green tea, "chaksol" or "chugno", is most often served, other teas such as "Byeoksoryung" Chunhachoon, Woojeon, Jakseol, Jookro, Okcheon, as well as native chrysanthemum tea, persimmon leaf tea, or mugwort tea may be served at different times of the year.

Buddhist monks incorporated tea ceremonies into votive offerings. However the Goryeo nobility and later the Confucian yangban scholars formalized the rituals. Tea ceremonies have always been used for important occasions such as birthdays, anniversaries, remembrance of old friends, and increasingly a way to rediscovering Seon meditation.

Japanese Involvement

Importing tea and tea culture

The earliest known references to green tea in Japan are in a text written by a Buddhist monk in the 9th century. Tea became a drink of the religious classes in Japan when Japanese priests and envoys sent to China to learn about its culture brought tea to Japan. The first form of tea brought from China was probably in a teacake. Ancient recordings indicate the first batch of tea seeds were brought by a priest named Saicho (767-822) in 805 and then by another named Kukai (774-835) in 806. It became a drink of the royal classes when Emperor Saga , the Japanese emperor, encouraged the growth of tea plants. Seeds were imported from China, and cultivation in Japan began.

Kissa Yojoki - the Book of Tea

In 1191, the famous Zen priest Eisai (1141-1215) brought back tea seeds to Kyoto. Some of the tea seeds were given to the priest Myoe Shonin, and became the basis for Uji tea. The oldest tea specialty book in Japan, Kissa Yojoki (how to stay healthy by drinking tea) was written by Eisai. The two-volume book was written in 1211 after his second and last visit to China. The first sentence states, "Tea is the ultimate mental and medical remedy and has the ability to make one's life more full and complete". The preface describes how drinking tea can have a positive effect on the five vital organs, especially the heart. It discusses tea's medicinal qualities which include easing the effects of alcohol, acting as a stimulant, curing blotchiness, quenching thirst, eliminating indigestion, curing beriberi, preventing fatigue, and improving urinary and brain function. Part One also explains the shapes of tea plants, tea flowers and tea leaves and covers how to grow tea plants and process tea leaves. In Part Two, the book discusses the specific dosage and method required for individual physical ailments.

Eisai was also instrumental in introducing tea consumption to the warrior class, which rose to political prominence after the Heian Period. Eisai learned that the shogun Minamoto no Sanetomo had a habit of drinking too much every night. In 1214, Eisai presented a book he had written to the general, lauding the health benefits of tea drinking. After that, the custom of tea drinking became popular among the Samurai.

Very soon, green tea became a staple among cultured people in Japan -- a brew for the gentry and the Buddhist priesthood alike. Production grew and tea became increasingly accessible, though still a privilege enjoyed mostly by the upper classes.

Roasting process introduced to Japan

In the 13th century Ming dynasty, southern China and Japan enjoyed much cultural exchange. Significant merchandise was traded and the roasting method of processing tea became common in Kyushu, Japan. Since the steaming (9th century) and the roasting (13th century) method were brought to Japan during two different periods, these teas are completely distinct from each another.

Japan tea culture emerges

 

Japanese tea ceremony

The pastime made popular in China in the twelfth and thirteenth centuries -- reading poetry, writing calligraphy, painting, and discussing philosophy while enjoying tea – eventually became popular in Japan and with Samurai society. The modern tea ceremony developed over several centuries by Zen Buddhist monks under the original guidance of the monk Sen-no Rikyu (1522-1591). In fact, both the beverage and the ceremony surrounding it played a prominent role in feudal diplomacy. Many of the most important negotiations among feudal clan leaders were carried out in the austere and serene setting of the tea ceremony. By the end of the sixteenth century, the current "Way of Tea" was established. Eventually, green tea became available to the masses, making it the nation's most popular beverage.

Modern Japanese green tea

In 1740, Soen Nagatani developed Japanese sencha which is an unfermented form of green tea. To prepare sencha, tea leaves are first steam-pressed, then rolled and dried into a loose tea. The dried leaves are then ground and mixed with hot water to yield the final drink. Sencha is now one of Japan's mainstay teas. This is a formal hemp species tea which develops its deep green color. It has long been used as a mild sedative, to calm and soothe.

Rolling machines

At the end of the Meiji period (1868-1912), machine manufacturing of green tea was introduced and began replacing handmade tea. Machines took over the processes of primary drying, tea rolling, secondary drying, final rolling, and steaming.

Automation

Automation contributed to improved quality control and reduced labour. Sensor and computer controls were introduced to machine automation so that unskilled workers can produce superior tea without compromising in quality. Certain regions in Japan are known for special types of green tea, as well as for teas of exceptional quality, making the leaves themselves a highly valued commodity. This combination of Nature's bounty and manmade technical breakthroughs combine to produce the most exceptional green tea products sold on the market today. Today, roasted green tea is not as common in Japan and powdered tea is used in ceremonial fashion.

Tea spreads to the world

As the Venetian explorer Marco Polo failed to mention tea in his travel records, it is conjectured that the first Europeans to encounter tea were either Jesuits living in Beijing who attended the court of the last Ming Emperors; or Portuguese explorers visiting Japan in 1560. Russia discovered tea in 1618 after a Ming Emperor of China offered it as a gift to Czar Michael I.