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Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of Camellia sinensis, an evergreen shrub native to East Asia which probably originated in the borderlands of south-western China and northern Myanmar.^[3][4][5] Tea is also made, but rarely, from the leaves of Camellia taliensis.^[6][7][8] After plain water, tea is the most widely consumed drink in the world.^[9] There are many different types of tea; some have a cooling, slightly bitter, and astringent flavour,^[10] while others have profiles that include sweet, nutty, floral, or grassy notes. Tea has a stimulating effect in humans, primarily due to its caffeine content.^[11]

An early credible record of tea drinking dates to the third century AD, in a medical text written by Chinese physician Hua Tuo.^[12] It was popularised as a recreational drink during the Chinese Tang dynasty, and tea drinking subsequently spread to other East Asian countries. Portuguese priests and merchants introduced it to Europe during the 16th century.^[13] During the 17th century, drinking tea became fashionable among the English, who started to plant tea on a large scale in British India.

The term herbal tea refers to drinks not made from Camellia sinensis. They are the infusions of fruit, leaves, or other plant parts, such as steeps of rosehip, chamomile, or rooibos. These may be called tisanes or herbal infusions to prevent confusion with tea made from the tea plant.

Etymology

Main article: Etymology of tea

The etymology of the various words for tea reflects the history of transmission of tea drinking culture and trade from China to countries around the world.^[14] Nearly all of the words for tea worldwide fall into three broad groups: te, cha and chai, present in English as tea, cha or char, and chai. The earliest of the three to enter English is cha, which came in the 1590s via the Portuguese, who traded in Macao and picked up the Cantonese pronunciation of the word.^[15][16] The more common tea form arrived in the 17th century via the Dutch, who acquired it either indirectly from the Malay teh, or directly from the tê pronunciation in Min Chinese.^[15] The third form chai (meaning “spiced tea”) originated from a northern Chinese pronunciation of cha, which travelled overland to Central Asia and Persia where it picked up a Persian ending yi. The Chinese word for tea itself was likely ultimately derived from the non-Sinitic languages of the botanical homeland of the tea plant in southwest China (or Burma), possibly from an archaic Austro-Asiatic root word *la, meaning “leaf”.^[17]

Origin and history

Further information: History of tea and History of tea in China

Botanical origin

Tea plants are native to East Asia and the probable center of origin of tea is near the source of the Irrawaddy River from where it spread out fan-wise into southeast China, Indo-China and Assam. Thus, the natural home of the tea plant is considered to be within the comparatively small fan-shaped area between Nagaland, Manipur and Mizoram along the Burma frontier in the west, through China as far as the Zhejiang Province in the east, and from this line generally south through the hills to Burma and Thailand to Vietnam. The west–east axis indicated above is about 2,400 km long extending from longitude 95°-120°E. The north–south axis covers about 1,920 km, starting from the northern part of Burma, latitude 29°N passing through Yunnan, Tongkin, Thailand, Laos and on to Annan, reaching latitude 11°N.^[18]

Chinese (small-leaf) type tea (C. sinensis var. sinensis) may have originated in southern China possibly with hybridization of unknown wild tea relatives. However, since there are no known wild populations of this tea, its origin is speculative.^[19][20]

Given their genetic differences forming distinct clades, Chinese Assam-type tea (C. sinensis var. assamica) may have two different parentages – one being found in southern Yunnan (Xishuangbanna, Pu’er City) and the other in western Yunnan (Lincang, Baoshan). Many types of Southern Yunnan Assam tea have been hybridized with the closely related species Camellia taliensis. Unlike Southern Yunnan Assam tea, Western Yunnan Assam tea shares many genetic similarities with Indian Assam-type tea (also C. sinensis var. assamica). Thus, Western Yunnan Assam tea and Indian Assam tea both may have originated from the same parent plant in the area where southwestern China, Indo-Burma, and Tibet meet. However, as the Indian Assam tea shares no haplotypes with Western Yunnan Assam tea, Indian Assam tea is likely to have originated from an independent domestication. Some Indian Assam tea appears to have hybridized with the species Camellia pubicosta.^[19][20]

Assuming a generation of 12 years, Chinese small-leaf tea is estimated to have diverged from Assam tea around 22,000 years ago, while Chinese Assam tea and Indian Assam tea diverged 2,800 years ago. The divergence of Chinese small-leaf tea and Assam tea would correspond to the last glacial maximum.^[19][20]

Early tea drinking

People in ancient East Asia ate tea for centuries, perhaps even millennia, before ever consuming it as a beverage. They would nibble on the leaves raw, add them to soups or greens, or ferment them and chew them as areca nut is chewed.^[22]

Tea drinking may have begun in the region of Yunnan, where it was used for medicinal purposes. It is believed that in Sichuan, “people began to boil tea leaves for consumption into a concentrated liquid without the addition of other leaves or herbs, thereby using tea as a bitter yet stimulating drink, rather than as a medicinal concoction.”^[5]

Chinese legends attribute the invention of tea to the mythical Shennong (in central and northern China) in 2737 BC, although evidence suggests that tea drinking may have been introduced from the southwest of China (Sichuan/Yunnan area).^[21] The earliest written records of tea come from China. The word tú 荼 appears in the Shijing and other ancient texts to signify a kind of “bitter vegetable” (苦菜), and it is possible that it referred to many different plants such as sow thistle, chicory, or smartweed,^[23] as well as tea.^[24] In the Chronicles of Huayang, it was recorded that the Ba people in Sichuan presented tu to the Zhou king. The Qin later conquered the state of Ba and its neighbour Shu, and according to the 17th century scholar Gu Yanwu who wrote in Ri Zhi Lu (日知錄): “It was after the Qin had taken Shu that they learned how to drink tea.”^[2] Another possible early reference to tea is found in a letter written by the Qin dynasty general Liu Kun who requested that some “real tea” to be sent to him.^[25]

The earliest known physical evidence^[26] of tea was discovered in 2016 in the mausoleum of Emperor Jing of Han in Xi’an, indicating that tea from the genus Camellia was drunk by Han dynasty emperors as early as the second century BC.^[27] The Han dynasty work “The Contract for a Youth”, written by Wang Bao in 59 BC,^[28] contains the first known reference to boiling tea. Among the tasks listed to be undertaken by the youth, the contract states that “he shall boil tea and fill the utensils” and “he shall buy tea at Wuyang”.^[2] The first record of tea cultivation is dated to this period, during which tea was cultivated on Meng Mountain (蒙山) near Chengdu.^[29] Another early credible record of tea drinking dates to the 3rd century AD, in a medical text by the Chinese physician Hua Tuo, who stated, “to drink bitter t’u constantly makes one think better.”^[30] However, before the Tang dynasty, tea-drinking was primarily a southern Chinese practice centered in Jiankang.^[31] Tea was disdained by the Northern dynasties aristocrats, who describe it as inferior to yogurt.^[32][33] It became widely popular during the Tang dynasty, when it spread to Korea, Japan, and Vietnam. The Classic of Tea, a treatise on tea and its preparations, was written by the 8th century Chinese writer, Lu Yu. He was known to have influenced tea drinking on a large part in China.^[34]

Developments

Through the centuries, a variety of techniques for processing tea, and a number of different forms of tea, were developed. During the Tang dynasty, tea was steamed, then pounded and shaped into cake form,^[35] while in the Song dynasty, loose-leaf tea was developed and became popular. During the Yuan and Ming dynasties, unoxidized tea leaves were first stirred in a hot dry pan, then rolled and air-dried, a process that stops the oxidation process that would have turned the leaves dark, thereby allowing tea to remain green. In the 15th century, oolong tea, in which the leaves are allowed to partially oxidize before being heated in the pan, was developed.^[31] Western tastes, however, favoured the fully oxidized black tea, and the leaves were allowed to oxidize further. Yellow tea was an accidental discovery in the production of green tea during the Ming dynasty, when apparently careless practices allowed the leaves to turn yellow, which yielded a different flavour.^[36]

Worldwide spread

See also: Arabic tea, Korean tea, Tea in Australia, and Tea in France

Tea was first introduced to Western priests and merchants in China during the 16th century, at which time it was termed chá.^[13] The earliest European reference to tea, written as chiai, came from Delle navigationi e viaggi written by Venetian Giambattista Ramusio in 1545.^[37] The first recorded shipment of tea by a European nation was in 1607 when the Dutch East India Company moved a cargo of tea from Macao to Java, then two years later, the Dutch bought the first assignment of tea which was from Hirado in Japan to be shipped to Europe.^[38] Tea became a fashionable drink in The Hague in the Netherlands, and the Dutch introduced the drink to Germany, France, and across the Atlantic to New Amsterdam (New York).^[39]

In 1567, Russian people came in contact with tea when the Cossack Atamans Petrov and Yalyshev visited China.^[40] The Mongolian Khan donated to Tsar Michael I four poods (65–70 kg) of tea in 1638.^[41] According to Jeremiah Curtin,^[42] it was possibly in 1636^[43] that Vassili Starkov was sent as envoy to the Altyn Khan. He was given 250 pounds of tea as a gift to the tsar. Starkov at first refused, seeing no use for a load of dead leaves, but the Khan insisted. Thus was tea introduced to Russia. In 1679, Russia concluded a treaty on regular tea supplies from China via camel caravan in exchange for furs. It is today considered the de facto national beverage.

The first record of tea in English came from a letter written by Richard Wickham, who ran an East India Company office in Japan, writing to a merchant in Macao requesting “the best sort of chaw” in 1615. Peter Mundy, a traveller and merchant who came across tea in Fujian in 1637, wrote, “chaa – only water with a kind of herb boyled in it”.^[44][45] Tea was sold in a coffee house in London in 1657, Samuel Pepys tasted tea in 1660, and Catherine of Braganza took the tea-drinking habit to the English court when she married Charles II in 1662. Tea, however, was not widely consumed in the British Isles until the 18th century and remained expensive until the latter part of that period. English drinkers preferred to add sugar and milk to black tea, and black tea overtook green tea in popularity in the 1720s.^[46] Tea smuggling during the 18th century led to the general public being able to afford and consume tea. The British government removed the tax on tea, thereby eliminating the smuggling trade, by 1785.^[47] In Britain and Ireland, tea was initially consumed as a luxury item on special occasions, such as religious festivals, wakes, and domestic work gatherings. The price of tea in Europe fell steadily during the 19th century, especially after Indian tea began to arrive in large quantities; by the late 19th century tea had become an everyday beverage for all levels of society.^[48] The popularity of tea played a role in historical events – the Tea Act of 1773 provoked the Boston Tea Party that escalated into the American Revolution. The need to address the issue of British trade deficit because of the trade in tea resulted in the Opium Wars. The Qing Kangxi Emperor had banned foreign products from being sold in China, decreeing in 1685 that all goods bought from China must be paid for in silver coin or bullion.^[49] Traders from other nations then sought to find another product, in this case opium, to sell to China to earn back the silver they were required to pay for tea and other commodities. The subsequent attempts by the Chinese Government to curtail the trade in opium led to war.^[50]

Chinese small-leaf-type tea was introduced into India in 1836 by the British in an attempt to break the Chinese monopoly on tea.^[51] In 1841, Archibald Campbell brought seeds of Chinese tea from the Kumaun region and experimented with planting tea in Darjeeling. The Alubari tea garden was opened in 1856, and Darjeeling tea began to be produced.^[52] In 1848, Robert Fortune was sent by the East India Company on a mission to China to bring the tea plant back to Great Britain. He began his journey in high secrecy as his mission occurred in the lull between the First Opium War and the Second Opium War.^[53] The Chinese tea plants he brought back were introduced to the Himalayas, though most did not survive. The British had discovered that a different variety of tea was endemic to Assam and the northeast region of India, which was then hybridized with Chinese small-leaf-type tea. Using Chinese planting and cultivation techniques, the British colonial government established a tea industry by offering land in Assam to any European who agreed to cultivate it for export.^[51] Tea was originally consumed only by Anglo-Indians; however, it became widely popular in India in the 1950s because of a successful advertising campaign by the India Tea Board.^[51] The British introduced tea industry to Sri Lanka (then Ceylon) in 1867.^[54]

Chemical composition

See also: Phenolic content in tea

Physically speaking, tea has properties of both a solution and a suspension. It is a solution of the water-soluble compounds extracted from the tea leaves, such as the polyphenols and amino acids. Tea infusions are among most consumed beverages globally.^[55]

Caffeine makes up about 3% of tea’s dry weight, which translates to between 30 and 90 milligrams per 250-millilitre (8+¹⁄₂ US fl oz) cup depending on the type, brand,^[56] and brewing method.^[57] A study found that the caffeine content of one gram of black tea ranged from 22 to 28 mg, while the caffeine content of one gram of green tea ranged from 11 to 20 mg, reflecting a significant difference.^[58] Tea contains small amounts of theobromine and theophylline, which are xanthines and stimulants, similar to caffeine.^[59]

The astringency in tea can be attributed to the presence of polyphenols. These are the most abundant compounds in tea leaves, making up 30–40% of their composition.^[60] Polyphenols in tea include flavonoids, epigallocatechin gallate (EGCG), and other catechins.^[61][62] Although there has been preliminary clinical research on whether green or black teas may protect against various human diseases, there is no evidence that tea polyphenols have any effect on health or lowering disease risk.^[63][64]

Health effects

Main article: Health effects of tea

Although health benefits have been assumed throughout the history of Camellia sinensis‘s consumption, there is no high-quality evidence showing that tea consumption gives significant benefits other than possibly increasing alertness, an effect caused by caffeine in the tea leaves.^[65][66] In clinical research conducted in the early 21st century, it was found there is no scientific evidence to indicate that consuming tea affects any disease or improves health.^[65]

Black and green teas contain no essential nutrients in significant amounts, with the exception of the dietary mineral manganese, at 0.5 mg per cup or 26% of the Reference Daily Intake (RDI).^[67] Fluoride is sometimes present in tea; certain types of “brick tea”, made from old leaves and stems, have the highest levels, enough to pose a health risk if much tea is drunk, which has been attributed to high levels of fluoride in soils, acidic soils, and long brewing.^[68]

Cultivation and harvesting

Camellia sinensis is an evergreen plant that grows mainly in tropical and subtropical climates.^[69] Some varieties can tolerate oceanic climates and are cultivated as far north as Cornwall in England,^[70] Perthshire in Scotland,^[71] Washington in the United States,^[72] and Vancouver Island in Canada.^[73] In the Southern Hemisphere, tea is grown as far south as Hobart in Tasmania^[74][75] and Waikato in New Zealand.^[76]

Tea plants are propagated from seed and cuttings; about 4 to 12 years are needed for a plant to bear seed and about three years before a new plant is ready for harvesting.^[69] In addition to a zone 8 climate or warmer, tea plants require at least 127 cm (50 in) of rainfall per year and prefer acidic soils.^[77] Many high-quality tea plants are cultivated at elevations of up to 1,500 m (4,900 ft) above sea level. Though at these heights the plants grow more slowly, they acquire a better flavour.^[78]

Two principal varieties are used: Camellia sinensis var. sinensis, which is used for most Chinese, Formosan and Japanese teas, and C. sinensis var. assamica, used in Pu-erh and most Indian teas (but not Darjeeling). Within these botanical varieties, many strains and modern clonal varieties are known. Leaf size is the chief criterion for the classification of tea plants, with three primary classifications being:^[79] Assam type, characterised by the largest leaves; China type, characterised by the smallest leaves; and Cambodian type, characterised by leaves of intermediate size. The Cambodian-type tea (C. assamica subsp. lasiocaly) was originally considered a type of Assam tea. However, later genetic work showed that it is a hybrid between Chinese small-leaf tea and Assam-type tea.^[80] Darjeeling tea appears to be a hybrid between Chinese small-leaf tea and Assam-type large-leaf tea.^[20]

A tea plant will grow into a tree of up to 16 m (52 ft) if left undisturbed,^[69] but cultivated plants are generally pruned to waist height for ease of plucking. The short plants bear more new shoots which provide new and tender leaves and increase the quality of the tea.^[81] Only the top 2.5–5 centimetres (1–2 in) of the mature plant are picked. These buds and leaves are called ‘flushes’.^[82] A plant will grow a new flush every 7 to 15 days during the growing season. Leaves that are slow in development tend to produce better-flavoured teas.^[69] Several teas are available from specified flushes; for example, Darjeeling tea is available as first flush (at a premium price), second flush, monsoon and autumn. Assam second flush or “tippy” tea is considered superior to first flush, because of the gold tips that appear on the leaves.

Pests that can afflict tea plants include mosquito bugs, genus Helopeltis, which are true bugs and not to be confused with dipterous insects of family Culicidae (‘mosquitos’). Mosquito bugs can damage leaves both by sucking plant materials, and by the laying of eggs (oviposition) within the plant. Spraying with synthetic insecticides may be deemed appropriate.^[83] Other pests are Lepidopteran leaf feeders and various tea diseases.

Production

Country	Million tonnes
China	14.53
India	5.97
Kenya	2.33
Sri Lanka	1.40
Turkey	1.30
Vietnam	1.12
Indonesia	0.60
Bangladesh	0.44
Argentina	0.36
Uganda	0.33
World	29.76
Source: (FAO)[84]

Tea is mainly grown in Asia and Africa, with smaller areas in South America and around the Black and Caspian Seas. The four biggest tea-producing countries are China, India, Kenya and Sri Lanka, together representing 81% of world tea production. Smaller hubs of production include such places as São Miguel Island, Azores, in Portugal, and Guria, in Georgia. In 2022, global production of tea was 29.8 million tonnes, led by China with 49% and India with 20% of the world total. Kenya, Sri Lanka, and Turkey were secondary producers.^[85]

Storage

Storage conditions determine the shelf life of tea; that of black teas is greater than that of green teas. Some, such as flower teas, may last only a month or so. Others, such as pu-erh, improve with age. To remain fresh and prevent mold, tea needs to be stored away from heat, light, air, and moisture. Tea must be kept at room temperature in an air-tight container. Black tea in a bag within a sealed opaque canister may keep for two years. Green tea deteriorates more rapidly, usually in less than a year. Tightly rolled gunpowder tea leaves keep longer than the more open-leafed Chun Mee tea.

Storage life for all teas can be extended by using desiccant or oxygen-absorbing packets, vacuum sealing, or refrigeration in air-tight containers (except green tea, where discrete use of refrigeration or freezing is recommended and temperature variation kept to a minimum).^[86]

Processing and classification

Main article: Tea processing

Tea is divided into categories based on how it is processed.^[87] At least six different types are produced:

• White: wilted and unoxidized;
• Yellow: unwilted and unoxidized but allowed to yellow;
• Green: unwilted and unoxidized;
• Oolong: wilted, bruised, and partially oxidized;
• Black: wilted, sometimes crushed, and fully oxidized (called 紅茶 [hóngchá], “red tea” in Chinese and other East Asian tea culture);
• Post-fermented (Dark): green tea that has been allowed to ferment/compost (called Pu’er if from the Yunnan district of South-Western China or 黑茶 [hēichá] “black tea” in Chinese tea culture).

After picking, the leaves of C. sinensis soon begin to wilt and oxidize unless immediately dried. An enzymatic oxidation process triggered by the plant’s intracellular enzymes causes the leaves to turn progressively darker as their chlorophyll breaks down and tannins are released. This darkening is stopped at a predetermined stage by heating, which deactivates the enzymes responsible. In the production of black teas, halting by heating is carried out simultaneously with drying. Without careful moisture and temperature control during manufacture and packaging, growth of undesired molds and bacteria may make tea unfit for consumption.

Blending and additives

Further information: Tea blending and additives

After basic processing, teas may be altered through additional processing steps before being sold^[88] and is often consumed with additions to the basic tea leaf and water added during preparation or drinking. Examples of additional processing steps that occur before tea is sold are blending, flavouring, scenting, and decaffeination of teas. Examples of additions added at the point of consumption include milk, sugar and lemon.

Tea blending is the combination of different teas together to achieve the final product. Such teas may combine others from the same cultivation area or several different ones. The aim is to obtain consistency, better taste, higher price, or some combination of the three.

Flavoured and scented teas are enhancements of the base tea. This can be accomplished through directly adding flavouring agents, such as ginger, cloves, mint leaves, cardamom, bergamot (found in Earl Grey), vanilla, and spearmint. Alternatively, because tea easily retains odours, it can be placed in proximity to an aromatic ingredient to absorb its aroma, as in traditional jasmine tea.^[89]

The addition of milk to tea in Europe was first mentioned in 1680 by the epistolist Madame de Sévigné.^[90] Many teas are traditionally drunk with milk in cultures where dairy products are consumed. These include Indian masala chai and British tea blends. These teas tend to be very hearty varieties of black tea which can be tasted through the milk, such as Assams, or the East Friesian blend. Milk is thought to neutralise remaining tannins and reduce acidity.^[91][92] The Han Chinese do not usually drink milk with tea but the Manchus do, and the elite of the Qing Dynasty of the Chinese Empire continued to do so. Hong Kong-style milk tea is based on British habits. Tibetans and other Himalayan peoples traditionally drink tea with milk or yak butter and salt. In Eastern European countries, and in Russia and Italy, tea is commonly served with lemon juice. In Poland, tea is traditionally served with a slice of lemon and is sweetened with either sugar or honey; tea with milk is called a bawarka (“Bavarian style”) in Polish and is widely popular.^[93] In Australia, tea with milk is known as “white tea”.

The order of steps in preparing a cup of tea is a much-debated topic and can vary widely between cultures and individuals. Some say it is preferable to add the milk to the cup before the tea, as the high temperature of freshly brewed tea can denature the proteins found in fresh milk, similar to the change in taste of UHT milk, resulting in an inferior-tasting beverage.^[94] Others insist it is better to add the milk to the cup after the tea, as black tea is often brewed as close to boiling as possible. The addition of milk chills the beverage during the crucial brewing phase, if brewing in a cup rather than using a pot, meaning the delicate flavour of a good tea cannot be fully appreciated. By adding the milk afterwards, it is easier to dissolve sugar in the tea and to ensure the desired amount of milk is added, as the colour of the tea can be observed.^[95] Historically, the order of steps was taken as an indication of class: only those wealthy enough to afford good-quality porcelain would be confident of its being able to cope with being exposed to boiling water unadulterated with milk.^[96] Higher temperature difference means faster heat transfer, so the earlier milk is added, the slower the drink cools. A 2007 study published in the European Heart Journal found certain beneficial effects of tea may be lost through the addition of milk.^[97]

Packaging

Tea bags

Main article: Tea bag

In 1907, American tea merchant Thomas Sullivan began distributing samples of his tea in small bags of silk with a drawstring. Consumers noticed they could simply leave the tea in the bag and reuse it with fresh tea. However, the potential of this distribution and packaging method would not be fully realised until later. During World War II, tea was rationed in the United Kingdom. In 1953, after rationing in the UK ended, Yorkshire-based tea manufacturer Tetley launched the tea bag in the UK, and it was an immediate success.

The “pyramid tea bag” (or sachet), introduced by Lipton^[98] and PG Tips/Scottish Blend in 1996,^[99] attempts to address one of the connoisseurs’ arguments against paper tea bags by way of its three-dimensional tetrahedron shape, which allows more room for tea leaves to expand while steeping.^[100] However, some types of pyramid tea bags have been criticised as being environmentally unfriendly, since their synthetic material is not as biodegradable as loose tea leaves and paper tea bags.^[101]

Loose tea

The tea leaves are packaged loosely in a canister, paper bag, or other container such as a tea chest. Some whole teas, such as rolled gunpowder tea leaves, which resist crumbling, are vacuum-packed for freshness in aluminised packaging for storage and retail. The loose tea is individually measured for use, allowing for flexibility and flavour control at the expense of convenience. Strainers, tea balls, tea presses, filtered teapots, and infusion bags prevent loose leaves from floating in the tea and over-brewing. A traditional method uses a three-piece lidded teacup called a gaiwan, the lid of which is tilted to decant the tea into a different cup for consumption.

Compressed tea

Tea bricks or compressed tea are produced for convenience in transport, storage, and ageing. It can usually be stored longer without spoilage than loose leaf tea. Compressed tea is prepared by loosening leaves from the cake using a small knife, and steeping the extracted pieces in water. During the Tang dynasty, as described by Lu Yu, compressed tea was ground into a powder, combined with hot water, and ladled into bowls, resulting in a “frothy” mixture.^[102] In the Song dynasty, the tea powder would instead be whisked with hot water in the bowl. Although no longer practiced in China today, the whisking method of preparing powdered tea was transmitted to Japan by Zen Buddhist monks, and is still used to prepare matcha in the Japanese tea ceremony.^[103] Chinese pu-erh is often distributed in the form, as other teas may sometimes be.

Compressed tea was the most popular form of tea in China during the Tang dynasty.^[104] By the beginning of the Ming dynasty, it had been displaced by loose-leaf tea.^[105] It remains popular, however, in the Himalayan countries and Mongolian steppes. In Mongolia, tea bricks were ubiquitous enough to be used as a form of currency. Among Himalayan peoples, compressed tea is consumed by combining it with yak butter and salt to produce butter tea.^[106]

Instant tea

Main article: Instant tea

“Instant tea”, similar to freeze-dried instant coffee and an alternative to brewed tea, can be consumed either hot or cold. Instant tea was developed in the 1930s, with Nestlé introducing the first commercial product in 1946, while Redi-Tea debuted instant iced tea in 1953. Additives such as chai, vanilla, honey or fruit, are popular, as is powdered milk.

During the Second World War British and Canadian soldiers were issued an instant tea in their composite ration (“compo”) packs. These blocks of instant tea, powdered milk, and sugar were not always well received. As Royal Canadian Artillery Gunner, George C Blackburn observed:

But, unquestionably, the feature of Compo rations destined to be remembered beyond all others is Compo tea…Directions say to “sprinkle powder on heated water and bring to the boil, stirring well, three heaped teaspoons to one pint of water.” Every possible variation in the preparation of this tea was tried, but…it always ended up the same way. While still too hot to drink, it is a good-looking cup of strong tea. Even when it becomes just cool enough to be sipped gingerly, it is still a good-tasting cup of tea, if you like your tea strong and sweet. But let it cool enough to be quaffed and enjoyed, and your lips will be coated with a sticky scum that forms across the surface, which if left undisturbed will become a leathery membrane that can be wound around your finger and flipped away…^[107]

Bottled and canned tea

Main article: Canned tea

Canned tea is sold prepared and ready to drink. It was introduced in 1981 in Japan. The first bottled tea was introduced by an Indonesian tea company, PT. Sinar Sosro in 1969 with the brand name Teh Botol Sosro (or Sosro bottled tea).^[108] In 1983, Swiss-based Bischofszell Food Ltd. was the first company to bottle iced tea on an industrial scale.^[109]

Tea culture

Main article: Tea culture

See also: American tea culture, Argentine tea culture, Azerbaijani tea culture, Brazilian tea culture, Dominican tea culture, Tea culture in Japan, Mexican tea culture, Russian tea culture, and Senegalese tea culture

In many cultures, tea is consumed at elevated social events, such as the tea party. Tea ceremonies have arisen in different cultures, such as the Chinese and Japanese traditions, each of which employs certain techniques and ritualised protocol of brewing and serving tea for enjoyment in a refined setting. One form of Chinese tea ceremony is the Gongfu tea ceremony, which typically uses small Yixing clay teapots and oolong tea.

In the United Kingdom, 63% of people drink tea daily.^[110] It is customary for a host to offer tea to guests soon after their arrival. Tea is consumed both at home and outside the home, often in cafés or tea rooms. Afternoon tea with cakes on fine porcelain is a cultural stereotype. In southwest England, many cafés serve a cream tea, consisting of scones, clotted cream, and jam alongside a pot of tea.

Ireland, as of 2016, was the second-biggest per capita consumer of tea in the world, after Turkey.^[111] Local blends are the most popular in Ireland, including Irish breakfast tea, using Rwandan, Kenyan and Assam teas. The annual national average of tea consumption in Ireland is 2.7 kg to 4 kg per person. Tea in Ireland is usually taken with milk or sugar and brewed longer for a stronger taste.^[112]

Turkish tea is an important part of that country’s cuisine and is the most commonly consumed hot drink, despite the country’s long history with coffee. In 2004, Turkey produced 205,500 tonnes of tea (6.4% of the global total), which made it one of the largest tea markets in the world,^[113] with 120,000 tons being consumed in Turkey and the rest being exported.^[114] In 2010, Turkey had the highest per capita consumption in the world at 2.7 kg.^[115] As of 2013, the per-capita consumption of Turkish tea exceeds 10 cups per day and 13.8 kg per year.^[116] Tea is grown mostly in Rize Province on the Black Sea coast.^[117]

Russia has a long, rich tea history dating to 1638 when tea was introduced to Tsar Michael. Social gatherings were considered incomplete without tea, which was traditionally brewed in a samovar.^[118]

In Pakistan, both black and green teas are popular and are known locally as sabz chai and kahwah, respectively. The popular green tea is often served after every meal in the Pashtun belt of Balochistan and in Khyber Pakhtunkhwa. In central and southern Punjab and the metropolitan Sindh region of Pakistan, tea with milk and sugar (sometimes with pistachios, cardamom, etc.), commonly referred to as chai, is widely consumed. It is the most common beverage of households in the region. In the northern Pakistani regions of Chitral and Gilgit-Baltistan, a salty, buttered Tibetan-style tea is consumed.

Indian tea culture is strong; the drink is the most popular hot beverage in the country. It is consumed daily^[119] in almost all houses, offered to guests, consumed in high amounts in domestic and official surroundings, and is made with the addition of milk with or without spices, and usually sweetened. It is sometimes served with biscuits to be dipped in the tea and eaten before consuming the tea. More often than not, it is drunk in “doses” of small cups (referred to as “cutting” chai if sold at street tea vendors) rather than one large cup.

Iranians have one of the highest per capita rates of tea consumption in the world. Châikhânes (teahouses) are common in Iran.^[120] Iranian tea is typically served in traditional Iranian glasses with a traditional saucer and teaspoon. Tea is cultivated in northern Iran along the shores of the Caspian Sea.^[121]

In Burma (Myanmar), tea is consumed not only as hot drinks, but also as sweet tea and green tea known locally as laphet-yay and laphet-yay-gyan, respectively. Pickled tea leaves, known locally as lahpet, are a national delicacy. Pickled tea is usually eaten with roasted sesame seeds, crispy fried beans, roasted peanuts and fried garlic chips.^[122]

In Mali, gunpowder tea is served in series of three, starting with the highest oxidisation or strongest, unsweetened tea, locally referred to as “strong like death”, followed by a second serving, where the same tea leaves are boiled again with some sugar added (“pleasant as life”), and a third one, where the same tea leaves are boiled for the third time with yet more sugar added (“sweet as love”). Green tea is the central ingredient of a distinctly Malian custom, the “Grin”, an informal social gathering that cuts across social and economic lines, starting in front of family compound gates in the afternoons and extending late into the night, and is widely popular in Bamako and other large urban areas.^[123]

In the United States, 80% of tea is consumed as iced tea.^[124] Sweet tea is native to the southeastern U.S. and is iconic in its cuisine due to its refreshing temperature and large amount of sweetener.^[125]

• Turkish tea served in a typical small glass and corresponding plate
• English teaware
• Iced tea with a slice of lemon
• Indian masala tea
• Bubble tea
• Hibiscus tea
• Thai tea

Economics

Producers and consumers

Further information: List of countries by tea consumption per capita

Tea is the most popular manufactured drink consumed in the world, equaling all others – including coffee, soft drinks, and alcohol – combined.^[9] Most tea consumed outside East Asia is produced on large plantations in the hilly regions of India and Sri Lanka and is destined to be sold to large businesses. Opposite this large-scale industrial production are many small “gardens,” sometimes minuscule plantations, that produce highly sought-after teas prized by gourmets. These teas are both rare and expensive and can be compared to some of the most expensive wines in this respect.^{[citation needed]}

India is the world’s largest tea-drinking nation,^[126] although the per capita consumption of tea remains a modest 750 grams (26 oz) per person every year. Turkey, with 2.5 kilograms (5 lb 8 oz) of tea consumed per person per year, is the world’s greatest per capita consumer.^[127]

Certification

Several bodies independently certify the production of tea, such as Rainforest Alliance, Fairtrade, UTZ Certified, and Organic. From 2008 to 2016, sustainability standards-certified tea production experienced a compound annual growth rate of about 35%, accounting for at least 19% of overall tea production. In 2016, at least 1.15 million tonnes of sustainably certified tea was produced, valued at US$2 billion.^[128]

Rainforest Alliance certified tea is sold by Unilever brands Lipton and PG Tips in Western Europe, Australia and the U.S. Fairtrade certified tea is sold by a large number of suppliers around the world. UTZ Certified tea is sold by Pickwick tea.^{[citation needed]}

Issues

Safety

Tests of commercially popular teas have detected residues of banned toxic pesticides.^[129][130]

Fraud

Tea is a common target of food fraud. Lower cost ingredients may be substituted for tea, or a tea may be adulterated with undeclared and possibly toxic colors and flavors. The origin of the tea, picking season, and the processing techniques may be intentionally misidentified. Tea powders which undergo additional processing are more susceptible to food fraud.^[131]

Labour

Tea production in Kenya, Malawi, Rwanda, Tanzania, and Uganda uses child labour, according to the U.S. Department of Labor‘s List of Goods Produced by Child Labor or Forced Labor.^[132] Workers who pick and pack tea on plantations in developing countries can face harsh working conditions and may earn below the living wage.^[133]

Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two molecules of glucose). White sugar is a refined form of sucrose. In the body, compound sugars are hydrolysed into simple sugars.

Sugars (clockwise from top-left): white refined, unrefined, brown, unprocessed cane

Longer chains of monosaccharides (>2) are not regarded as sugars and are called oligosaccharides or polysaccharides. Starch is a glucose polymer found in plants, the most abundant source of energy in human food. Some other chemical substances, such as ethylene glycol, glycerol and sugar alcohols, may have a sweet taste but are not classified as sugar.

Sugars are found in the tissues of most plants. Honey and fruits are abundant natural sources of simple sugars. Sucrose is especially concentrated in sugarcane and sugar beet, making them ideal for efficient commercial extraction to make refined sugar. In 2016, the combined world production of those two crops was about two billion tonnes. Maltose may be produced by malting grain. Lactose is the only sugar that cannot be extracted from plants. It can only be found in milk, including human breast milk, and in some dairy products. A cheap source of sugar is corn syrup, industrially produced by converting corn starch into sugars, such as maltose, fructose and glucose.

Sucrose is used in prepared foods (e.g., cookies and cakes), is sometimes added to commercially available ultra-processed food and beverages, and is sometimes used as a sweetener for foods (e.g., toast and cereal) and beverages (e.g., coffee and tea). The average person consumes about 24 kilograms (53 pounds) of sugar each year. North and South Americans consume up to 50 kg (110 lb), and Africans consume under 20 kg (44 lb).^[1]

As free sugar consumption grew in the latter part of the 20th century, researchers began to examine whether a diet high in free sugar, especially refined sugar, was damaging to human health. In 2015, the World Health Organization strongly recommended that adults and children reduce their intake of free sugars to less than 10% of their total energy intake and encouraged a reduction to below 5%.^[2] In general, high sugar consumption damages human health more than it provides nutritional benefit and is associated with a risk of cardiometabolic and other health detriments.^[3]

Etymology

[edit]

The etymology of sugar reflects the commodity’s spread. From Sanskrit śarkarā, meaning “ground or candied sugar”, came Persian shakar and Arabic sukkar. The Arabic word was borrowed in Medieval Latin as succarum, whence came the 12th century French sucre and the English sugar. Sugar was introduced into Europe by the Arabs in Sicily and Spain.^[4]

The English word jaggery, a coarse brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin: Portuguese jágara from the Malayalam cakkarā, which is from the Sanskrit śarkarā.^[5]

History

[edit]

Main article: History of sugar

Ancient world to Renaissance

[edit]

Asia

[edit]

Sugar has been produced in the Indian subcontinent^[6] for thousands of years. Sugarcane cultivation spread from there into China via the Khyber Pass and caravan routes.^[7] It was not plentiful or cheap in early times, and in most parts of the world, honey was more often used for sweetening.^[8] Originally, people chewed raw sugarcane to extract its sweetness. Even after refined sugarcane became more widely available during the European colonial era,^[9] palm sugar was preferred in Java and other sugar producing parts of southeast Asia, and along with coconut sugar, is still used locally to make desserts today.^[10][11]

Sugarcane is native of tropical areas such as the Indian subcontinent (South Asia) and Southeast Asia.^[6][12] Different species seem to have originated from different locations; Saccharum barberi originated in India, and S. edule and S. officinarum came from New Guinea.^[12][13] One of the earliest historical references to sugarcane is in Chinese manuscripts dating to the 8th century BCE, which state that the use of sugarcane originated in India.^[14]

In the tradition of Indian medicine (āyurveda), sugarcane is known by the name Ikṣu, and sugarcane juice is known as Phāṇita. Its varieties, synonyms and characteristics are defined in nighaṇṭus such as the Bhāvaprakāśa (1.6.23, group of sugarcanes).^[15]

Sugar remained relatively unimportant until the Indians discovered methods of turning sugarcane juice into granulated crystals that were easier to store and transport. At around 350 AD, Indian figure out a way to create crystalized sugar from the sugarcane juice. It was then considered as ‘sweet spice’ and Indian trader started trading suagr outside India.^[16] The Greek physician Pedanius Dioscorides attested to the method in his 1st century CE medical treatise De Materia Medica:

There is a kind of coalesced honey called sakcharon [i.e. sugar] found in reeds in India and Eudaimon Arabia similar in consistency to salt and brittle enough to be broken between the teeth like salt,

— Pedanius Dioscorides, Materia Medica, Book II^[17][18]

In the local Indian language, these crystals were called khanda (Devanagari: खण्ड, Khaṇḍa), which is the source of the word candy.^[19] Indian sailors, who carried clarified butter and sugar as supplies, introduced knowledge of sugar along the various trade routes they travelled.^[20] Traveling Buddhist monks took sugar crystallization methods to China.^[21] During the reign of Harsha (r. 606–647) in North India, Indian envoys in Tang China taught methods of cultivating sugarcane after Emperor Taizong of Tang (r. 626–649) made known his interest in sugar. China established its first sugarcane plantations in the seventh century.^[22] Chinese documents confirm at least two missions to India, initiated in 647 CE, to obtain technology for sugar refining.^[23]

Europe

[edit]

Nearchus, admiral of Alexander the Great, knew of sugar during the year 325 BC because of his participation in the campaign of India led by Alexander (Arrian, Anabasis).^[24][25] In addition to the Greek physician Pedanius Dioscorides, the Roman Pliny the Elder also described sugar in his 1st century CE Natural History: “Sugar is made in Arabia as well, but Indian sugar is better. It is a kind of honey found in cane, white as gum, and it crunches between the teeth. It comes in lumps the size of a hazelnut. Sugar is used only for medical purposes.“^[26] Crusaders brought sugar back to Europe after their campaigns in the Holy Land, where they encountered caravans carrying “sweet salt”. Early in the 12th century, the Republic of Venice acquired some villages near Tyre and set up estates to produce sugar for export to Europe. It supplemented the use of honey, which had previously been the only available sweetener.^[27] Crusade chronicler William of Tyre, writing in the late 12th century, described sugar as “very necessary for the use and health of mankind”.^[28] In the 15th century, Venice was the chief sugar refining and distribution center in Europe.^[14]

There was a drastic change in the mid-15th century, when Madeira and the Canary Islands were settled from Europe and sugar introduced there.^[29][30] After this an “all-consuming passion for sugar … swept through society” as it became far more easily available, though initially still very expensive.^[31] By 1492, Madeira was producing over 1,400,000 kilograms (3,000,000 lb) of sugar annually.^[32] Genoa, one of the centers of distribution, became known for candied fruit, while Venice specialized in pastries, sweets (candies), and sugar sculptures. Sugar was considered to have “valuable medicinal properties” as a “warm” food under prevailing categories, being “helpful to the stomach, to cure cold diseases, and sooth lung complaints”.^[33]

A feast given in Tours in 1457 by Gaston de Foix, which is “probably the best and most complete account we have of a late medieval banquet” includes the first mention of sugar sculptures, as the final food brought in was “a heraldic menagerie sculpted in sugar: lions, stags, monkeys … each holding in paw or beak the arms of the Hungarian king“.^[34] Other recorded grand feasts in the decades following included similar pieces.^[35] Originally the sculptures seem to have been eaten in the meal, but later they become merely table decorations, the most elaborate called trionfi. Several significant sculptors are known to have produced them; in some cases their preliminary drawings survive. Early ones were in brown sugar, partly cast in molds, with the final touches carved. They continued to be used until at least the Coronation Banquet for Edward VII of the United Kingdom in 1903; among other sculptures every guest was given a sugar crown to take away.^[36]

Modern history

[edit]

See also: Triangular trade

Sugar cane; demand for sugar contributed to creating colonial systems in areas where cultivation of sugar cane was profitable.

Hacienda La Fortuna. A sugar mill complex in Puerto Rico, painted by Francisco Oller in 1885, Brooklyn Museum

In August 1492, Christopher Columbus collected sugar cane samples in La Gomera in the Canary Islands, and introduced it to the New World.^[37] The cuttings were planted and the first sugar-cane harvest in Hispaniola took place in 1501. Many sugar mills had been constructed in Cuba and Jamaica by the 1520s.^[38] The Portuguese took sugar cane to Brazil. By 1540, there were 800 cane-sugar mills in Santa Catarina Island and another 2,000 on the north coast of Brazil, Demarara, and Surinam. It took until 1600 for Brazilian sugar production to exceed that of São Tomé, which was the main center of sugar production in sixteenth century.^[30]

German chemists Andreas Sigismund Marggraf (left) and Franz Karl Achard (right) both laid the foundation of the modern sugar industry.

Sugar was a luxury in Europe until the early 19th century, when it became more widely available, due to the rise of beet sugar in Prussia, and later in France under Napoleon.^[39] Beet sugar was a German invention, since, in 1747, Andreas Sigismund Marggraf announced the discovery of sugar in beets and devised a method using alcohol to extract it.^[40] Marggraf’s student, Franz Karl Achard, devised an economical industrial method to extract the sugar in its pure form in the late 18th century.^[41][42] Achard first produced beet sugar in 1783 in Kaulsdorf, and in 1801, the world’s first beet sugar production facility was established in Cunern, Silesia (then part of Prussia, now Poland).^[43] The works of Marggraf and Achard were the starting point for the sugar industry in Europe,^[44] and for the modern sugar industry in general, since sugar was no longer a luxury product and a product almost only produced in warmer climates.^[45]

Sugar became highly popular and by the 19th century, was found in every household. This evolution of taste and demand for sugar as an essential food ingredient resulted in major economic and social changes.^[46] Demand drove, in part, the colonization of tropical islands and areas where labor-intensive sugarcane plantations and sugar manufacturing facilities could be successful.^[46] World consumption increased more than 100 times from 1850 to 2000, led by Britain, where it increased from about 2 pounds per head per year in 1650 to 90 pounds by the early 20th century. In the late 18th century Britain consumed about half the sugar which reached Europe.^[47]

After slavery was abolished, the demand for workers in European colonies in the Caribbean was filled by indentured laborers from the Indian subcontinent.^[48][49][50] Millions of enslaved or indentured laborers were brought to various European colonies in the Americas, Africa and Asia (as a result of demand in Europe for among other commodities, sugar), influencing the ethnic mixture of numerous nations around the globe.^[51][52][53]

Sugar also led to some industrialization of areas where sugar cane was grown. For example, in the 1790s Lieutenant J. Paterson, of the Bengal Presidency promoted to the British parliament the idea that sugar cane could grow in British India, where it had started, with many advantages and at less expense than in the West Indies. As a result, sugar factories were established in Bihar in eastern India.^[54][55] During the Napoleonic Wars, sugar-beet production increased in continental Europe because of the difficulty of importing sugar when shipping was subject to blockade. By 1880 the sugar beet was the main source of sugar in Europe. It was also cultivated in Lincolnshire and other parts of England, although the United Kingdom continued to import the main part of its sugar from its colonies.^[56]

Until the late nineteenth century, sugar was purchased in loaves, which had to be cut using implements called sugar nips.^[57] In later years, granulated sugar was more usually sold in bags. Sugar cubes were produced in the nineteenth century. The first inventor of a process to produce sugar in cube form was Jakob Christof Rad, director of a sugar refinery in Dačice. In 1841, he produced the first sugar cube in the world.^[58] He began sugar-cube production after being granted a five-year patent for the process on 23 January 1843. Henry Tate of Tate & Lyle was another early manufacturer of sugar cubes at his refineries in Liverpool and London. Tate purchased a patent for sugar-cube manufacture from German Eugen Langen, who in 1872 had invented a different method of processing of sugar cubes.^[59]

Sugar was rationed during World War I, though it was said that “No previous war in history has been fought so largely on sugar and so little on alcohol”,^[60] and more sharply during World War II.^{[61][62][63][64][65]} Rationing led to the development and use of various artificial sweeteners.^[61][66]

Chemistry

[edit]

Scientifically, sugar loosely refers to a number of carbohydrates, such as monosaccharides, disaccharides, or oligosaccharides. Monosaccharides are also called “simple sugars”, the most important being glucose. Most monosaccharides have a formula that conforms to C
_nH
_2nO
_n with n between 3 and 7 (deoxyribose being an exception). Glucose has the molecular formula C
₆H
₁₂O
₆. The names of typical sugars end with –ose, as in “glucose” and “fructose“. Sometimes such words may also refer to any types of carbohydrates soluble in water. The acyclic mono- and disaccharides contain either aldehyde groups or ketone groups. These carbon-oxygen double bonds (C=O) are the reactive centers. All saccharides with more than one ring in their structure result from two or more monosaccharides joined by glycosidic bonds with the resultant loss of a molecule of water (H
₂O) per bond.^[67]

Monosaccharides in a closed-chain form can form glycosidic bonds with other monosaccharides, creating disaccharides (such as sucrose) and polysaccharides (such as starch or cellulose). Enzymes must hydrolyze or otherwise break these glycosidic bonds before such compounds become metabolized. After digestion and absorption the principal monosaccharides present in the blood and internal tissues include glucose, fructose, and galactose. Many pentoses and hexoses can form ring structures. In these closed-chain forms, the aldehyde or ketone group remains non-free, so many of the reactions typical of these groups cannot occur. Glucose in solution exists mostly in the ring form at equilibrium, with less than 0.1% of the molecules in the open-chain form.^[67]

Natural polymers

[edit]

Biopolymers of sugars are common in nature. Through photosynthesis, plants produce glyceraldehyde-3-phosphate (G3P), a phosphated 3-carbon sugar that is used by the cell to make monosaccharides such as glucose (C
₆H
₁₂O
₆) or (as in cane and beet) sucrose (C
₁₂H
₂₂O
₁₁). Monosaccharides may be further converted into structural polysaccharides such as cellulose and pectin for cell wall construction or into energy reserves in the form of storage polysaccharides such as starch or inulin. Starch, consisting of two different polymers of glucose, is a readily degradable form of chemical energy stored by cells, and can be converted to other types of energy.^[67] Another polymer of glucose is cellulose, which is a linear chain composed of several hundred or thousand glucose units. It is used by plants as a structural component in their cell walls. Humans can digest cellulose only to a very limited extent, though ruminants can do so with the help of symbiotic bacteria in their gut.^[68] DNA and RNA are built up of the monosaccharides deoxyribose and ribose, respectively. Deoxyribose has the formula C
₅H
₁₀O
₄ and ribose the formula C
₅H
₁₀O
₅.^[69]

Flammability and heat response

[edit]

Because sugars burn easily when exposed to flame, the handling of sugars risks dust explosion. The risk of explosion is higher when the sugar has been milled to superfine texture, such as for use in chewing gum.^[70] The 2008 Georgia sugar refinery explosion, which killed 14 people and injured 36, and destroyed most of the refinery, was caused by the ignition of sugar dust.^[71]

In its culinary use, exposing sugar to heat causes caramelization. As the process occurs, volatile chemicals such as diacetyl are released, producing the characteristic caramel flavor.^[72]

Types

[edit]

Monosaccharides

[edit]

Fructose, galactose, and glucose are all simple sugars, monosaccharides, with the general formula C₆H₁₂O₆. They have five hydroxyl groups (−OH) and a carbonyl group (C=O) and are cyclic when dissolved in water. They each exist as several isomers with dextro- and laevo-rotatory forms that cause polarized light to diverge to the right or the left.^[73]

• Fructose, or fruit sugar, occurs naturally in fruits, some root vegetables, cane sugar and honey and is the sweetest of the sugars. It is one of the components of sucrose or table sugar. It is used as a high-fructose syrup, which is manufactured from hydrolyzed corn starch that has been processed to yield corn syrup, with enzymes then added to convert part of the glucose into fructose.^[74]
• Galactose generally does not occur in the free state but is a constituent with glucose of the disaccharide lactose or milk sugar. It is less sweet than glucose. It is a component of the antigens found on the surface of red blood cells that determine blood groups.^[75]
• Glucose occurs naturally in fruits and plant juices and is the primary product of photosynthesis. Starch is converted into glucose during digestion, and glucose is the form of sugar that is transported around the bodies of animals in the bloodstream. Although in principle there are two enantiomers of glucose (mirror images one of the other), naturally occurring glucose is D-glucose. This is also called dextrose, or grape sugar because drying grape juice produces crystals of dextrose that can be sieved from the other components.^[76] Glucose syrup is a liquid form of glucose that is widely used in the manufacture of foodstuffs. It can be manufactured from starch by enzymatic hydrolysis.^[77] For example, corn syrup, which is produced commercially by breaking down maize starch, is one common source of purified dextrose.^[78] However, dextrose is naturally present in many unprocessed, whole foods, including honey and fruits such as grapes.^[79]

Disaccharides

[edit]

Lactose, maltose, and sucrose are all compound sugars, disaccharides, with the general formula C₁₂H₂₂O₁₁. They are formed by the combination of two monosaccharide molecules with the exclusion of a molecule of water.^[73]

• Lactose is the naturally occurring sugar found in milk. A molecule of lactose is formed by the combination of a molecule of galactose with a molecule of glucose. It is broken down when consumed into its constituent parts by the enzyme lactase during digestion. Children have this enzyme but some adults no longer form it and they are unable to digest lactose.^[80]
• Maltose is formed during the germination of certain grains, the most notable being barley, which is converted into malt, the source of the sugar’s name. A molecule of maltose is formed by the combination of two molecules of glucose. It is less sweet than glucose, fructose or sucrose.^[73] It is formed in the body during the digestion of starch by the enzyme amylase and is itself broken down during digestion by the enzyme maltase.^[81]
• Sucrose is found in the stems of sugarcane and roots of sugar beet. It also occurs naturally alongside fructose and glucose in other plants, in particular fruits and some roots such as carrots. The different proportions of sugars found in these foods determines the range of sweetness experienced when eating them.^[73] A molecule of sucrose is formed by the combination of a molecule of glucose with a molecule of fructose. After being eaten, sucrose is split into its constituent parts during digestion by a number of enzymes known as sucrases.^[82]

Sources

[edit]

The sugar contents of common fruits and vegetables are presented in Table 1.

Food item	Total carbohydrateA including dietary fiber	Total sugars	Free fructose	Free glucose	Sucrose	Fructose/ (Fructose+Glucose) ratioB	Sucrose as a % of total sugars
Fruits
Apple	13.8	10.4	5.9	2.4	2.1	0.67	20
Apricot	11.1	9.2	0.9	2.4	5.9	0.42	64
Banana	22.8	12.2	4.9	5.0	2.4	0.5	20
Fig, dried	63.9	47.9	22.9	24.8	0.9	0.48	1.9
Grapes	18.1	15.5	8.1	7.2	0.2	0.53	1
Navel orange	12.5	8.5	2.25	2.0	4.3	0.51	51
Peach	9.5	8.4	1.5	2.0	4.8	0.47	57
Pear	15.5	9.8	6.2	2.8	0.8	0.67	8
Pineapple	13.1	9.9	2.1	1.7	6.0	0.52	61
Plum	11.4	9.9	3.1	5.1	1.6	0.40	16
Strawberry	7.68	4.89	2.441	1.99	0.47	0.55	10
Vegetables
Beet, red	9.6	6.8	0.1	0.1	6.5	0.50	96
Carrot	9.6	4.7	0.6	0.6	3.6	0.50	77
Corn, sweet	19.0	6.2	1.9	3.4	0.9	0.38	15
Red pepper, sweet	6.0	4.2	2.3	1.9	0.0	0.55	0
Onion, sweet	7.6	5.0	2.0	2.3	0.7	0.47	14
Sweet potato	20.1	4.2	0.7	1.0	2.5	0.47	60
Yam	27.9	0.5	tr	tr	tr	na	tr
Sugar cane		13–18	0.2–1.0	0.2–1.0	11–16	0.50	high
Sugar beet		17–18	0.1–0.5	0.1–0.5	16–17	0.50	high

^A The carbohydrate figure is calculated in the USDA database and does not always correspond to the sum of the sugars, the starch, and the dietary fiber.^[why?]^B The fructose to fructose plus glucose ratio is calculated by including the fructose and glucose coming from the sucrose.

Production

[edit]

See also: List of sugars

Due to rising demand, sugar production in general increased some 14% over the period 2009 to 2018.^[84] The largest importers were China, Indonesia, and the United States.^[84]

Sugar

[edit]

In 2022–2023 world production of sugar was 186 million tonnes, and in 2023–2024 an estimated 194 million tonnes — a surplus of 5 million tonnes, according to Ragus.^[85]

Sugarcane

[edit]

Sugarcane production – 2022
Country	Millions of tonnes
Brazil	724.4
India	439.4
China	103.4
Thailand	92.1
World	1,922.1
Source: FAO[86]

Sugar cane accounted for around 21% of the global crop production over the 2000–2021 period. The Americas was the leading region in the production of sugar cane (52% of the world total).^[87] Global production of sugarcane in 2022 was 1.9 billion tonnes, with Brazil producing 38% of the world total and India 23% (table).

Sugarcane is any of several species, or their hybrids, of giant grasses in the genus Saccharum in the family Poaceae. They have been cultivated in tropical climates in the Indian subcontinent and Southeast Asia over centuries for the sucrose found in their stems.^[6]

Sugar cane requires a frost-free climate with sufficient rainfall during the growing season to make full use of the plant’s substantial growth potential. The crop is harvested mechanically or by hand, chopped into lengths and conveyed rapidly to the processing plant (commonly known as a sugar mill) where it is either milled and the juice extracted with water or extracted by diffusion.^[89] The juice is clarified with lime and heated to destroy enzymes. The resulting thin syrup is concentrated in a series of evaporators, after which further water is removed. The resulting supersaturated solution is seeded with sugar crystals, facilitating crystal formation and drying.^[89] Molasses is a by-product of the process and the fiber from the stems, known as bagasse,^[89] is burned to provide energy for the sugar extraction process. The crystals of raw sugar have a sticky brown coating and either can be used as they are, can be bleached by sulfur dioxide, or can be treated in a carbonatation process to produce a whiter product.^[89] About 2,500 litres (660 US gal) of irrigation water is needed for every one kilogram (2.2 pounds) of sugar produced.^[90]

Sugar beet

[edit]

Sugar beet production – 2022
Country	Millions of tonnes
Russia	48.9
France	31.5
United States	29.6
Germany	28.2
World	260
Source: FAO[86]

In 2022, global production of sugar beets was 260 million tonnes, led by Russia with 18.8% of the world total (table).

Sugar beet became a major source of sugar in the 19th century when methods for extracting the sugar became available. It is a biennial plant,^[91] a cultivated variety of Beta vulgaris in the family Amaranthaceae, the tuberous root of which contains a high proportion of sucrose. It is cultivated as a root crop in temperate regions with adequate rainfall and requires a fertile soil. The crop is harvested mechanically in the autumn and the crown of leaves and excess soil removed. The roots do not deteriorate rapidly and may be left in the field for some weeks before being transported to the processing plant where the crop is washed and sliced, and the sugar extracted by diffusion.^[92] Milk of lime is added to the raw juice with calcium carbonate. After water is evaporated by boiling the syrup under a vacuum, the syrup is cooled and seeded with sugar crystals. The white sugar that crystallizes can be separated in a centrifuge and dried, requiring no further refining.^[92]

Refining

[edit]

See also: Sugar refinery, Non-centrifugal cane sugar, and White sugar

Refined sugar is made from raw sugar that has undergone a refining process to remove the molasses.^[93][94] Raw sugar is sucrose which is extracted from sugarcane or sugar beet. While raw sugar can be consumed, the refining process removes unwanted tastes and results in refined sugar or white sugar.^[95][96]

The sugar may be transported in bulk to the country where it will be used and the refining process often takes place there. The first stage is known as affination and involves immersing the sugar crystals in a concentrated syrup that softens and removes the sticky brown coating without dissolving them. The crystals are then separated from the liquor and dissolved in water. The resulting syrup is treated either by a carbonatation or by a phosphatation process. Both involve the precipitation of a fine solid in the syrup and when this is filtered out, many of the impurities are removed at the same time. Removal of color is achieved by using either a granular activated carbon or an ion-exchange resin. The sugar syrup is concentrated by boiling and then cooled and seeded with sugar crystals, causing the sugar to crystallize out. The liquor is spun off in a centrifuge and the white crystals are dried in hot air and ready to be packaged or used. The surplus liquor is made into refiners’ molasses.^[97]

The International Commission for Uniform Methods of Sugar Analysis sets standards for the measurement of the purity of refined sugar, known as ICUMSA numbers; lower numbers indicate a higher level of purity in the refined sugar.^[98]

Refined sugar is widely used for industrial needs for higher quality. Refined sugar is purer (ICUMSA below 300) than raw sugar (ICUMSA over 1,500).^[99] The level of purity associated with the colors of sugar, expressed by standard number ICUMSA, the smaller ICUMSA numbers indicate the higher purity of sugar.^[99]

Forms and uses

[edit]

Crystal size

[edit]

See also: Rock candy, Sucrose, and Powdered sugar

Misri crystals

Rock candy coloured with green dye

• Coarse-grain sugar, also known as sanding sugar, composed of reflective crystals with grain size of about 1 to 3 mm, similar to kitchen salt. Used atop baked products and candies, it will not dissolve when subjected to heat and moisture.^[100]
• Granulated sugar (about 0.6 mm crystals), also known as table sugar or regular sugar, is used at the table, to sprinkle on foods and to sweeten hot drinks (coffee and tea), and in home baking to add sweetness and texture to baked products (cookies and cakes) and desserts (pudding and ice cream). It is also used as a preservative to prevent micro-organisms from growing and perishable food from spoiling, as in candied fruits, jams, and marmalades.^[101]
• Milled sugars such as powdered sugar (icing sugar) are ground to a fine powder. They are used for dusting foods and in baking and confectionery.^[102][100]
• Screened sugars such as caster sugar are crystalline products separated according to the size of the grains. They are used for decorative table sugars, for blending in dry mixes and in baking and confectionery.^[102]

Shapes

[edit]

“Lump sugar” redirects here. For the South Korean film, see Lump Sugar.

• Cube sugar (sometimes called sugar lumps) are white or brown granulated sugars lightly steamed and pressed together in block shape. They are used to sweeten drinks.^[102]
• Sugarloaf was the usual cone-form in which refined sugar was produced and sold until the late 19th century.^[103]

Brown sugars

[edit]

Main article: Brown sugar

Brown sugars are granulated sugars, either containing residual molasses, or with the grains deliberately coated with molasses to produce a light- or dark-colored sugar such as muscovado and turbinado. They are used in baked goods, confectionery, and toffees.^[102] Their darkness is due to the amount of molasses they contain. They may be classified based on their darkness or country of origin.^[100]

Liquid sugars

[edit]

• Syrups are thick, viscous liquids consisting primarily of a solution of sugar in water. They are used in the food processing of a wide range of products including beverages, hard candy, ice cream, and jams.^[102]
  • Inverted sugar syrup, commonly known as invert syrup or invert sugar, is a mixture of two simple sugars—glucose and fructose—that is made by heating granulated sugar in water. It is used in breads, cakes, and beverages for adjusting sweetness, aiding moisture retention and avoiding crystallization of sugars.^[102]
• Molasses and treacle are obtained by removing sugar from sugarcane or sugar beet juice, as a byproduct of sugar production. They may be blended with the above-mentioned syrups to enhance sweetness and used in a range of baked goods and confectionery including toffees and licorice.^[102]
• In winemaking, fruit sugars are converted into alcohol by a fermentation process. If the must formed by pressing the fruit has a low sugar content, additional sugar may be added to raise the alcohol content of the wine in a process called chaptalization. In the production of sweet wines, fermentation may be halted before it has run its full course, leaving behind some residual sugar that gives the wine its sweet taste.^[104]

Other sweeteners

[edit]

See also: Saccharin

• Low-calorie sweeteners are often made of maltodextrin with added sweeteners. Maltodextrin is an easily digestible synthetic polysaccharide consisting of short chains of three or more glucose molecules and is made by the partial hydrolysis of starch.^[105] Strictly, maltodextrin is not classified as sugar as it contains more than two glucose molecules, although its structure is similar to maltose, a molecule composed of two joined glucose molecules.
• Polyols are sugar alcohols and are used in chewing gums where a sweet flavor is required that lasts for a prolonged time in the mouth.^[106]

Consumption

[edit]

Worldwide sugar provides 10% of the daily calories (based on a 2000 kcal diet).^[107] In 1750, the average Briton got 72 calories a day from sugar. In 1913, this had risen to 395. In 2015, sugar still provided around 14% of the calories in British diets.^[108] According to one source, per capita consumption of sugar in 2016 was highest in the United States, followed by Germany and the Netherlands.^[109]

Nutrition and flavor

[edit]

Nutritional value per 100 g (3.5 oz)
Energy	1,576 kJ (377 kcal)
Carbohydrates	97.33 g
Sugars	96.21 g
Dietary fiber	0 g
Fat	0 g
Protein	0 g
showVitamins and minerals
Other constituents	Quantity
Water	1.77 g
Full link to USDA database entry
†Percentages estimated using US recommendations for adults,[110] except for potassium, which is estimated based on expert recommendation from the National Academies.[111]

Nutritional value per 100 g (3.5 oz)
Energy	1,619 kJ (387 kcal)
Carbohydrates	99.98 g
Sugars	99.91 g
Dietary fiber	0 g
Fat	0 g
Protein	0 g
showVitamins and minerals
Other constituents	Quantity
Water	0.03 g
Full link to USDA database entry
†Percentages estimated using US recommendations for adults,[110] except for potassium, which is estimated based on expert recommendation from the National Academies.[111]

Brown and white granulated sugar are 97% to nearly 100% carbohydrates, respectively, with less than 2% water, and no dietary fiber, protein or fat (table). Brown sugar contains a moderate amount of iron (15% of the Reference Daily Intake in a 100 gram amount, see table), but a typical serving of 4 grams (one teaspoon), would provide 15 calories and a negligible amount of iron or any other nutrient.^[112] Because brown sugar contains 5–10% molasses reintroduced during processing, its value to some consumers is a richer flavor than white sugar.^[113]

Health effects

[edit]

Genera

[edit]

High sugar consumption damages human health more than it provides nutritional benefit, and in particular is associated with a risk of cardiometabolic health detriments.^[3]

Sugar industry funding and health information

[edit]

Main article: Sugar marketing § Influence on health information and guidelines

Sugar refiners and manufacturers of sugary foods and drinks have sought to influence medical research and public health recommendations,^[114][115] with substantial and largely clandestine spending documented from the 1960s to 2016.^{[116][117][118][119]} The results of research on the health effects of sugary food and drink differ significantly, depending on whether the researcher has financial ties to the food and drink industry.^{[120][121][122]} A 2013 medical review concluded that “unhealthy commodity industries should have no role in the formation of national or international NCD [non-communicable disease] policy”.^[123] Similar efforts to steer coverage of sugar-related health information have been made in popular media, including news media and social media.^{[124][125][126]}

Obesity and metabolic syndrome

[edit]

Main article: Diet and obesity § Sugar consumption

A 2003 technical report by the World Health Organization (WHO) provides evidence that high intake of sugary drinks (including fruit juice) increases the risk of obesity by adding to overall energy intake.^[127] By itself, sugar is doubtfully a factor causing obesity and metabolic syndrome.^[128] Meta-analysis showed that excessive consumption of sugar-sweetened beverages increased the risk of developing type 2 diabetes and metabolic syndrome – including weight gain^[129] and obesity – in adults and children.^[130][131]

Cancer

[edit]

Sugar consumption does not directly cause cancer.^{[132][133][134]} Cancer Council Australia have stated that “there is no evidence that consuming sugar makes cancer cells grow faster or cause cancer”.^[132] There is an indirect relationship between sugar consumption and obesity-related cancers through increased risk of excess body weight.^{[134][132][135]}

The American Institute for Cancer Research and World Cancer Research Fund recommend that people limit sugar consumption.^[136][137]

There is a popular misconception that cancer can be treated by reducing sugar and carbohydrate intake to supposedly “starve” tumours. In reality, the health of people with cancer is best served by maintaining a healthy diet.^[138]

Cognition

[edit]

Despite some studies suggesting that sugar consumption causes hyperactivity, the quality of evidence is low^[139] and it is generally accepted within the scientific community that the notion of children’s ‘sugar rush’ is a myth.^[140][141] A 2019 meta-analysis found that sugar consumption does not improve mood, but can lower alertness and increase fatigue within an hour of consumption.^[142] One review of low-quality studies of children consuming high amounts of energy drinks showed association with higher rates of unhealthy behaviors, including smoking and excessive alcohol use, and with hyperactivity and insomnia, although such effects could not be specifically attributed to sugar over other components of those drinks such as caffeine.^[143]

Tooth decay

[edit]

The WHO, Action on Sugar and the Scientific Advisory Committee on Nutrition (SACN) consider free sugars an essential dietary factor in the development of dental caries.^{[144][145][146]} WHO have stated that “dental caries can be prevented by avoiding dietary free sugars”.^[144]

A review of human studies showed that the incidence of caries is lower when sugar intake is less than 10% of total energy consumed.^[147] Sugar-sweetened beverage consumption is associated with an increased risk of tooth decay.^[148]

Nutritional displacement

[edit]

The “empty calories” argument states that a diet high in added (or ‘free’) sugars will reduce consumption of foods that contain essential nutrients.^[149] This nutrient displacement occurs if sugar makes up more than 25% of daily energy intake,^[150] a proportion associated with poor diet quality and risk of obesity.^[151] Displacement may occur at lower levels of consumption.^[150]

Recommended dietary intake

[edit]

The WHO recommends that both adults and children reduce the intake of free sugars to less than 10% of total energy intake, and suggests a reduction to below 5%. “Free sugars” include monosaccharides and disaccharides added to foods, and sugars found in fruit juice and concentrates, as well as in honey and syrups. According to the WHO, “[t]hese recommendations were based on the totality of available evidence reviewed regarding the relationship between free sugars intake and body weight (low and moderate quality evidence) and dental caries (very low and moderate quality evidence).”^[2]

On 20 May 2016, the U.S. Food and Drug Administration announced changes to the Nutrition Facts panel displayed on all foods, to be effective by July 2018. New to the panel is a requirement to list “added sugars” by weight and as a percent of Daily Value (DV). For vitamins and minerals, the intent of DVs is to indicate how much should be consumed. For added sugars, the guidance is that 100% DV should not be exceeded. 100% DV is defined as 50 grams. For a person consuming 2000 calories a day, 50 grams is equal to 200 calories and thus 10% of total calories—the same guidance as the WHO.^[152] To put this in context, most 12-US-fluid-ounce (355 ml) cans of soda contain 39 grams of sugar. In the United States, a government survey on food consumption in 2013–2014 reported that, for men and women aged 20 and older, the average total sugar intakes—naturally occurring in foods and added—were, respectively, 125 and 99 g/day.^[153]

Measurements

[edit]

Various culinary sugars have different densities due to differences in particle size and inclusion of moisture. The “Engineering Resources – Bulk Density Chart” published in Powder and Bulk gives values for bulk densities:^[154]

• Beet sugar 0.80 g/mL
• Dextrose sugar 0.62 g/mL ( = 620 kg/m^3)
• Granulated sugar 0.70 g/mL
• Powdered sugar 0.56 g/mL

Society and culture

[edit]

Manufacturers of sugary products, such as soft drinks and candy, and the Sugar Research Foundation have been accused of trying to influence consumers and medical associations in the 1960s and 1970s by creating doubt about the potential health hazards of sucrose overconsumption, while promoting saturated fat as the main dietary risk factor in cardiovascular diseases.^[116] In 2016, the criticism led to recommendations that diet policymakers emphasize the need for high-quality research that accounts for multiple biomarkers on development of cardiovascular diseases.^[116]

Originally, no sugar was white; anthropologist Sidney Mintz writes that white likely became understood as the ideal after groups who associated the color white with purity transferred their value to sugar.^[155] In India, sugar frequently appears in religious observances. For ritual purity, such sugar cannot be white.^[155]

Gallery

[edit]

• Brown sugar crystals
• Whole date sugar
• Whole cane sugar (grey), vacuum-dried
• Whole cane sugar (brown), vacuum-dried
• Raw crystals of unrefined, unbleached sugar