Coffee

Coffea cruda syn. C. arabica

Coffee Parts used Uses Habitat and cultivation Constituents Coffee processing

Coffee - imagine a sunny day in the distant past - perhaps a thousand years ago, perhaps much longer. A band of African warriors enters a damp highland forest, dense with the glossy undergrowth of 12- to 15 - foot-high broadleaved evergreens. Clustered at the leaf axils of these shrub like trees are rounded, deep red berries, no larger than the first joint of a man's little finger. The men know that something in the berries helps them to perform great feats of strength and bravery, and so they pluck a large supply of the berries to chew in preparation for the battle that lies ahead.

That "something" is caffeine, the same substance that a modern American seeks from a steaming breakfast brew. It stimulates the central nervous system: the flow of blood is increased, especially through the coronary arteries that feed the heart; the heart itself beats a bit faster; muscles respond to the urgent pulse; the kidneys work a little harder; breathing is stimulated; so is cerebral activity. One is more alert and ready to face the day.

After five or six cups of coffee, however, the mild stimulation is transformed into restlessness, irritability, feelings of nausea, even muscle tremors and mental instability. One has overdosed on the world's most popular medication.

Caffeine, derived from the two grayish seeds that dwell within each fruit of several Coffea species, was identified in 1821, by a scientist who mistakenly thought that the seeds might contain quinine. Today it is possible to enjoy the flavor of coffee without the effects of caffeine. Decaffeinated coffee is made by removing the caffeine while leaving the oil, called caffeol, which is responsible for the beverage's distinctive aroma and flavor. The extracted caffeine is not lost, however. It is sold to the pharmaceutical industry for incorporation into pain remedies, where its stimulating effect helps to rush such substances as aspirin and phenacetin into the system. It is also a cardiac and respiratory stimulant, of particular value in fighting overdoses of such central nervous system depressants as alcohol, barbiturates, and morphine.

C. arabica, which originated in Ethiopia, was introduced into Persia, Egypt, and Arab lands at some unknown date in antiquity. For a long time, the roasting, grinding, brewing, and consumption of the beans were the province of priests and medicine men. But by the 15th century, Mecca boasted several public coffeehouses. Similar establishments were later to spring up in Constantinople, in Venice, and (despite efforts by the church to ban the "infidel drink") in Rome. By the mid-17th century, coffee drinking had become highly fashionable in London, Paris, and Berlin.

The Arabs held a monopoly on coffee, most of which moved through the port of Mocha  - hence one popular name for coffee. Arabs were forbidden to export the plants or unroasted seeds, but in 1690 the Dutch smuggled out some seedlings. They set up coffee plantations in Java - hence another popular name. In the early 18th century, coffee trees were taken to Martinique and Jamaica, where they flourished. They soon went to other islands, to Central America, and to Brazil, which eventually became the world's leading coffee producer (a distinction that is today claimed by Colombia). In recent decades several African and Asian countries have taken large shares of the market, deriving their product from such species as C. canephora and C. liberica.

PARTS USED

Seeds.

USES

Although coffee is not often recognized as a medicinal herb, coffee is highly effective when taken as a general stimulant, having a particular effect on the central nervous system, temporarily improving perception and physical performance. Coffee increases heart output, stimulates digestive juices, and is a powerful diuretic. Coffee can help in headaches and migraine. Coffee's active constituent, caffeine, is often combined with conventional analgesics in over-the-counter headache remedies. In Ayurvedic medicine, the unripe beans are used for headaches, and the ripe, roasted beans for diarrhea. Coffee enemas effectively cleanse the large bowel.
Other medical uses - Homeopathy.

HABITAT AND CULTIVATION

Coffea arabica, which accounts for about 75% of all coffee consumption, is an evergreen tree or shrub that grows best in areas with moderate rainfall and at altitudes of between 2,000 feet and 6,500 feet above sea level. In Ecuador it is cultivated as high as 9,400 feet, while in subtropical Hawaii it is grown near the sea. It is also necessary for the temperature to remain as close as possible to 68°F. The variety that is cultivated commercially grows to a height of approximately 16 feet, though to ease harvesting it is frequently trimmed to a height of about 6 feet.

Three or four years after planting, Coffea arabica produces highly scented blossoms. The coffee berries ripen six to eight months later, changing from dark green to yellow, then to red, and eventually to deep crimson when they are fully ripe. Because of their size and general appearance, the ripe berries are known as coffee cherries. Beneath the crimson skin of the cherry is a moist, soft, sweet-tasting pulp that surrounds the green coffee bean. The bean itself has a thin, delicate, translucent covering known as the silver skin.

The proper time to harvest varies according to climate and altitude. Where conditions are less than ideal, as in southern Brazil, coffee is harvested only in the winter. Under perfect conditions, as in Java, planting is staggered throughout the year, and therefore the coffee can be harvested almost continuously. The berries are picked by hand or shaken from the bush onto mats.

Coffea arabica is a delicate plant which is plagued by more than 40 diseases caused by fungi, viruses, bacteria, and soil deficiencies. The worst disease is leaf rust caused by the fungus Hemileia vastatrix. The leaves die and drop off, and after a few years the bush dies. Leaf rust damage is a problem almost everywhere except in Central and South America, where farmers destroy the plants at the first sign of the disease. This success in fighting leaf rust explains why most Arabica coffee is grown there. Other, less serious diseases do occur, but mostly where growing conditions are marginal.

Coffea robusta (also known as Coffea canephora var. robusta) is grown mostly outside the Americas, although some is grown in Brazil. It is more tolerant of extremes of soil and climate and more resistant to diseases and insects than is Coffea arabica. Coffea robusta will also grow at lower altitudes. Coffee robusta berries take from two or three months longer to ripen than do C. arabica berries, though they typically yield larger harvests. In addition, harvesting is easier because the Coffee robusta berries stay on the tree when they are overripe. These differences mean that it costs less to grow C. robusta coffee, and this cost difference accounts for the increasing use of this coffee plant, despite its reportedly inferior taste.

CONSTITUENTS

Coffee contains 0.06-0.32% caffeine, theobromine and theophylline, and tannins. Caffeine is strongly stimulant. Theophylline is stimulant and relaxes smooth muscle.

COFFEE PROCESSING

There are two methods used to separate the bean from the berry. In the wet process, a pulping machine breaks open the freshly picked berries and removes the skin and some of the flesh beneath. They are then left in water for about 24 hours, during which time more of the flesh is loosened by the action of yeasts and bacteria (fermentation). Afterwards, the beans are washed and then dried in the sun. Finally their silver skin is removed and they are machine polished. This yields what are known by coffee traders as green beans. This wet process, used for all Arabica coffee berries except for those in Brazil, generally produces a higher grade of bean.

Dry processing is a less expensive method of separating the bean from the berry and is used for almost all Robusta coffees and for Arabica coffees in Brazil. In this method the berries are stripped from the plant and either dried in special machines or left to dry in the sun for two to three weeks. After this period the dried husks and silver skins are readily removed by machinery or even by hand to yield the green coffee beans. Dry processing produces beans which create a harsher tasting coffee than those beans processed by the wet method. For this reason Arabica coffee from Brazil tends not to be of the highest quality. When C. robusta berries are wet processed, as they are in Uganda, the result is a bean that is better than most other Robustas.

Much of the coffee that is consumed undergoes further processing to produce decaffeinated coffee. Because some of the oils and other flavor components of the coffee bean are lost during the various processes, the stronger tasting Robustas and the dry-processed Arabicas from Brazil are generally used.

In an attempt to remove 97% or more of the caffeine, while leaving or returning to the bean as much of the flavor components as possible, manufacturers use two primary techniques, the direct method and the water method. In the direct method, a chemical solvent, methylene chloride, is used to remove caffeine from the green beans; the solvent is then mixed with water and the caffeine is extracted for other uses. In the water method, the green beans are soaked in water; after the caffeine is removed from this water, the beans are once again returned to the water in an attempt to restore some of their flavor-retaining solids. Decaffeinated coffee produced by the direct method is generally superior in flavor to that produced by the water method, which removes most of the body and flavor along with the caffeine.

Roasting of both regular and decaffeinated green beans is generally carried out shortly before they reach the retail market. This is done commercially by passing the green beans through 260°C gases for up to 5 minutes, the length of roasting time depending on the desired darkness of the bean which in turn affects the taste and caffeine content of the brewed coffee. The bean loses water during roasting-14% during the shortest roast, known as "light city," which produces a cinnamon-colored bean, and 20% during the longest roast, known as "Italian," which produces a dark brown to black bean. The final step before brewing is grinding, which is usually done by the processor or in the store, but increasingly it is being done at the point of preparation in homes or restaurants so that no flavor is lost.

Instant coffee is produced from the roasted beans using one of two methods. Both begin by brewing a coffee extract in huge percolators. Pressurized water at 338°F is used to force more of the bean into solution. In the manufacture of spray-dried coffee the extract is fed into the top of a tower of hot air. This dries the extract into a powder, which can be recovered from the bottom of the tower. Freeze-dried coffee, more expensive though better tasting, takes advantage of the fact that the water and the solids in the coffee extract separate upon freezing. Afterwards the solids are granulated or turned into flakes.