Oddly enough, the story of Lt. Colonel Francisco de Melo Palheta, the military man responsible for planting the first coffee tree in Brazil, which itself became the progenitor of that country’s largest single crop to this day, is evocative of de Clieu’s. Palheta was a Spanish officer sent from Brazil to French Guiana to arbitrate an international controversy. While there, he engaged in an affair with the governor’s wife, who, in recognition of his erotic favors, gave him a bouquet at his departure in which was concealed a cutting of a coffee tree. Hitherto, the plant had been jealously and successfully kept from the Spanish colonies by the French and Dutch, but this smuggled lover’s gift breached their security, and so the Brazilian coffee line began.
Coffee Cultivation
Coffea arabica flourishes in areas with moderate rainfall, about forty to sixty inches evenly distributed throughout the year, and at altitudes of between four thousand and five thousand feet above sea level (although in Ecuador it is cultivated as high as ninety-four hundred feet, while in subtropical Hawaii it is grown at sea level), and grows best where the temperature remains close to 68 degrees Fahrenheit. Unlike most tropical plants, Coffea arabica can withstand low temperatures, although it is killed by frost. While the wild coffee tree grows to a height of twenty-five to thirty-five feet, the commercially cultivated variety of Coffea arabica attains only about sixteen feet and, to facilitate harvesting, is frequently trimmed to the height of a man.
Coffea arabica produces abundant small, white, highly fragrant blossoms that develop in clusters, three or four years after planting. Flowers that open on a dry, sunny day produce more fruit than those opening on a wet day because of a greater opportunity for wind and insect pollination. The stunning beauty of a coffee estate in flower is transient: After two or three days, even gentle breezes will strip the flowers away, leaving behind only the dark green foliage and the berries. About six to eight months later, what are called the berries (or, more properly, the drupes), about one-half to three-quarters of an inch long, ripen, changing from dark green to yellow, then to red, and finally to deep crimson. Because of their size, color, and gloss at maturity, the ripe berries are called “cherries” by farmers and processors. Beneath the red skin of these cherries is a moist, sweet-tasting fleshy pulp, good for eating, that surrounds the green coffee bean. Most cherries contain two locules, each locule housing a seed, or bean. The seeds are each sheathed by two coverings: a thin, hard endocarp, called the “parchment,” and a thin translucent membranous pellicle, called the “silver skin.” Some cherries contain three beans, while others, generally those at the tips of the branches, contain only one round bean, known as a “peaberry.” All parts of the fruit and the leaves contain caffeine.
The berries are picked by hand or shaken from the bush onto mats, producing a yield per acre that varies enormously, because a single tree, depending on its individual character and on climate and altitude, can produce between one and twelve pounds of dried beans a year. The best time for harvesting varies with the region in which the coffee is grown. Under ideal conditions, as in Java, planting is staggered throughout the year, blooming and fruiting are continuous, and therefore the coffee can be harvested almost continuously. Where conditions are less than perfect, as in parts of Brazil, coffee is harvested in the winter only.
Gourmet coffees are exclusively high-quality, mild varieties of Coffea arabica (“mild” in the coffee trade means lacking harsh, hard taste characteristics), principally from Latin America, excluding Brazil. Excellent varieties of Coffea arabica are also obtained from Kenya, Tanzania, Ethiopia, and Cameroon and the Yemen. Originally, all fine coffees came exclusively from the Yemen, from where they were shipped to the world through the port of Mocha. Soon after World War I, the wells of Mocha dried up, and coffee cultivation was largely abandoned. Today, the relatively small amount of coffee exported from the Yemen leaves through the port of Hodeida, but it still carries the traditional name of Mocha, which has never stopped being synonymous in the public’s mind with the best beans. Most Brazilian coffees are also varieties of Coffea arabica, but they are characterized by less refined flavor and aroma than those of the mild group.
In Costa Rica, competitively cultivating the Coffea arabica plant is essential to the nation’s livelihood. This means producing an abundant crop and processing it quickly and well. Traditionally, small coffee farmers tended their patches of plants. Today, they are being replaced by large plantation holders, who are increasingly planting an improved strain of Coffea arabica called “sun coffee.” The name for this variety, developed in the early 1970s, derives from the fact that, unlike other strains of the coffee tree that require a mixture of sun and shade, these new plants need, and can stand up to, the unremitting tropical blaze. That means that they can be planted without the benefit of a surrounding shade species. This is good news for farmers who are trying to increase coffee yields, because the entire acreage under cultivation can be dedicated exclusively to coffee plants. As against this agrarian strategy, some environmentalists argue that creating an exclusive crop, or monocrop, of coffee results in catastrophic soil erosion, causing massive damage to the land within a few years.
In 1898 the French merchant Emil Laurent took advantage of the recent discovery, made in Uganda near Lake Victoria, of canephora, a new species of Coffea. After identifying a variety of canephora, which he called “Coffea lauurentii,” he brought it for marketing to a Belgian horticultural firm. The firm decided that applying the name “robusta” to this variety would be conducive to sales of this harsher and more heavily caffeine-charged brew by suggesting both a robust flavor and a robust kick. The beans from Coffea robusta, although yielding coffee with a flatter and less aromatic flavor than Coffea arabica varieties, are nevertheless widely used, particularly in the form of soluble, or instant, coffees.
The hardiness of the plant is also suggested by its name, for Coffea robusta possesses greater strength and, because it contains nearly twice the caffeine (1.3 percent of the dry weight of arabica beans, as compared with 2.4 percent of the dry weight of robusta beans), greater resistance to disease and insects than Coffea arabica. It yields more fruit, grows at lower altitudes and in a wider variety of soil conditions, and adapts to warm humid climates to which Coffea arabica is not well suited. It also produces a full crop within four years, less than half the time needed for Coffea arabica. Coffea robusta berries take from two to three months longer to ripen than do Coffea arabica berries, though the plants typically yield larger harvests. Harvesting is easier because the Coffea robusta berries stay on the tree when they are fully ripe, instead of dropping off as do Coffea arabica berries, and so the picking can be delayed to suit the planter’s convenience. These differences mean that it costs less to grow and harvest Coffea robusta than Coffea arabica coffee, which accounts for its increasing use as a source of cheap blenders and as the basis of instant coffees, despite its inferior taste. Many familiar commercial coffee products are mixtures that combine the characteristics of different species and varieties, blended to satisfy a wide range of consumer tastes.
Like Coffea arabica, Coffea robusta flourishes between the Tropics of Capricorn and Cancer. Coffea robusta prefers rainfall of about 75 inches a year and temperatures of 60 to 80 degrees Fahrenheit. The biggest difference between the conditions favored by Coffea arabica and those favored by Coffea robusta is that Coffea robusta demonstrates a tolerance to more extreme conditions. Most notable is its ability to withstand humidity without succumbing to the bane of Coffea arabica, leaf spot disease (Hemileia vastatrix).9
Despite Laurent’s efforts on behalf of Coffea robusta, Coffea arabica remains the more widely grown, but many regions where temperature and humidity are high, especially those that have experienced the devastation of leaf spot disease, have been replanted with Coffea robusta. Coffea robusta coffees are now the major species grown in the less mountainous regions closest to the equator. African varieties of Coffea robusta today represent more than 25 percent of all coffee used i
n the United States and Europe.10
Coffee Oddities and Curiosities
Those embarked on an ongoing hunt for the best cup of coffee should find it tantalizing to discover that there is a species superior to Coffea arabica—declared by many to be the species of genus Coffea producing the most aromatic and flavorful coffee beans in the world—that is currently unavailable and likely to remain so for the indefinite future. Coffea stenophylla, by historical accounts, was considered superior to Coffea arabica in a number of important respects: It is a hardier plant, it produces a larger crop, and, most importantly for the coffee connoisseur, the brewed beans have a richer taste. In these respects Coffea stenophylla would seem to combine the advantages of both Coffea arabica and Coffea robusta and go them each one better. But bad timing doomed Coffea stenophylla to the limbo of uncultivated crops. The plant was discovered growing wild in Sierra Leone and introduced to various English colonies in 1895, at the same time that a massive epidemic of rust disease was eradicating many plantations. To recover from the blight, the farmers needed a plant that would turn out a crop as quickly as possible. This pointed them away from Coffea stenophylla, the main disadvantage of which is requiring nine years to reach maturity, two years longer than Coffea arabica and five years longer than Coffea robusta. As a result, even though it’s hardier and it produces more beans once it gets started, Coffea stenophylla has never gained a foothold in the marketplace.11
It has been reliably determined by French and German investigators that several species of Coffea, including Coffea gallienii, Coffea bonnieri, Coffea mogeneti, which grow wild in the Comoro Islands and Madagascar, are absolutely caffeine free. However they contain a bitter substance, cafamarine, that makes their beans unfit for use.12
A tea was and still is prepared from the leaves of the coffee plant, most notably in Arabia, Sumatra, and the West Indies. It is infused from the roasted leaves of the coffee tree in the same manner as regular tea, and it is preferred, where consumed, to coffee brewed from the bean.13 In Sumatra the bean crop was frequently ravaged by insects, and the growers, seeking a substitute that would contain caffeine, collected the leaves in their stead. The discovery that the leaves are high in caffeine was exploited during World War I by Dutch factories, who bought them by the ton in order to extract the stimulant for use by combat troops.
Another sort of coffee tea is a peninsular habit of Arabia and has been since at least the middle of the sixteenth century. In the land from which the coffee bean came, a beverage, commonly preferred in summer because of its “cooling” humoral properties, and exclusively consumed by the discriminating, was brewed from the husks of the bean. The decoction is said to resemble a sort of spicy, aromatic tea more than it does either modern Western or Turkish coffee.
The Kentucky Coffee Tree (Gymnocladus dioica) is a plant native to central and eastern North America and eastern China. Settlers ground the seeds to make a drink with some resemblance to coffee. Like guarana and yoco, these plants contain latherproducing saponin, but, unlike them, do not contain any caffeine.14
In sum, the primary botanical differences between the most popular and widely used coffee plants, Coffea arabica and Coffea robusta, are these: Coffea robusta will grow at relatively low altitudes, will tolerate higher temperatures and heavier rainfall, demands higher soil humus content, and is generally more resistant to disease. Coffea arabica beans are oval and green to yellowish green in color, while Coffea robusta beans are rounder and tend toward brownish shades. Of course the most important difference between the two species as far as coffee drinkers are concerned is that coffee made from Coffea arabica tastes and smells much better. Avicenna, the great Arab philosopher and physician, may have gotten it right a thousand years ago when he recommended beans “of a lemon color, light, and of a good smell.”15
The Tea Bush: E Pluribus Unum (Camellia sinensis)
There are many ways of classifying the drinks called “teas” and a bewildering variety of names for dozens of different types: black, green, oolong, China, Assam, flavored, scented, decaffeinated, tonics, barks, decoctions, infusions, and ptisanes, and an entire lexicon of trade names, such as “English Breakfast tea.” These rubrics codify differences in botanical varieties, growing conditions, admixtures, and methods of processing tea, but also include many drinks made exclusively from herbs and plants that are botanically unrelated to tea.
In simple fact, the tea leaves used in brewing tea grow on a single species, Camellia sinensis, a plant native to northern India, Tibet, and possibly China, regions where it is still chiefly cultivated. Yet because of ignorance about the differences produced by different processing methods and the fact that Camellia sinensis boasts a great number of varieties, or subspecies, for centuries there was considerable confusion as to whether there was one or more species of the plant. It was not until 1958 that botanists agreed internationally that there was one species with many varieties. Two of these varieties, Assam and China tea, have major commercial importance.
The two-hundred-year-old confusion over how to classify the tea bush began with the father of all botanical nomenclature, Carl von Linné (1707–78), or Carolus Lin-næus, Swedish botanist and inventor of the twofold naming system for classifying plants (which supplanted the clumsy Latin phrases employed previously) that is still used today. In Species Plantarium (1753), Linnæus divided tea into two species: the viridis, which produced green teas, and the bohea, which produced black.
Engraving from Dufour, Traitez Nouveaux. This French engraving shows two Chinese farm workers with their wicker baskets harvesting “Chinese tea on the bush” in the highlands, an exotic image for the seventeenth-century European audience for whom it was created. (The Library Company of Philadelphia)
However, as stated above, it is now accepted that all tea, including both the prolific Assam (assamica) and the hardy China (sinensis) teas, are varieties of a single species, Camellia sinensis.
The bewilderment over the meaning of tea types has been exacerbated by the fact that there are three distinct methods of processing tea leaves, each resulting in a recognizably different product: black tea, green tea, or oolong tea. Black tea (called “red tea” in China, after the color of the beverage rather than the darker color of the dried leaves) is created when fresh green leaves are withered after plucking, spread out to dry, and then crushed by rollers to bring out the aromatic oils; the crushed leaves then oxidize, or ferment, and assume their characteristic brown color. Green tea is produced by firing or steaming the fresh leaves immediately after picking, a step which prevents the leaves from oxidizing and precludes the natural fermentation that would otherwise occur. Oolong tea is prepared like black tea, but its leaves are allowed to ferment for only a short time before drying and turn only partially brown, acquiring a flavor that shares something of both black and green teas.16
The divisions of black, green, and oolong tea are based entirely on these differences in processing. It is possible to make all three kinds from the same tea bushes, something which is often done. However, certain regions typically specialize in producing a certain type, and because of this people often mistakenly think the tea grown in each place is botanically distinct. For example, virtually all Japanese tea is green, almost all Indian tea is black, while China produces green, black, and oolong tea.
All types of tea, as they are commonly prepared, contain less caffeine than coffee. Black tea infused for five minutes contains about 40 to 100 mg of caffeine in each cup; if infused for only three minutes it contains about half this amount. Green tea has less caffeine than black. Tea bags, because they contain broken leaves, produce a drink that contains more caffeine. In addition to caffeine, tea contains polyphenols, commonly known as “tannins,” and aromatic or essential oils. In China, medicines are made from the tannins to treat a variety of diseases including kidney and liver conditions. The essential oils are the source of tea’s distinctive aroma and reputedly act as a digestive aid. Green tea contains more essential oils than black, whic
h typically loses some of these in its longer processing, and therefore green tea has a stronger scent.17
Linnæus Brings Home the Tea: Osbek’s Trek and Other Tea Adventures
In the first half of the eighteenth century, when Linnæus undertook his lifework of classifying flora in accordance with a twofold scheme of his own devising, the world was a much bigger place than it is today. The great scientist’s acquaintance with the tea plant was limited by Chinese restrictions on foreign travelers and the unreliability of untutored observations of laymen who had somehow completed the difficult journey. Driven by scientific curiosity, Linnæus made a deal with the Swedish East India Company according to which one of his students would annually sail with the fleet for China and would so be able to return with specimens and accurate information about local conditions. Getting his hands on a tea plant, however, proved to be more difficult than he had originally thought.
Linnæus’ initial hopes rested on the shoulders of a young student, Per Osbek, who, like most of Linnæus’ mariner protégés, served as ship’s chaplain to pay for his food during the voyage. Although Osbek returned with a profuse variety of plants and pages of detailed observations, his attempt to deliver a tea plant was defeated by misadventures. One plant was knocked into the sea when Osbek’s crew fired the ship’s cannons in the traditional salute on departure. On a second voyage, he managed to bring a plant within sight of the Cape of Good Hope, only to watch it blow overboard during a sudden storm that recalls the one that menaced de Clieu and his coffee plant on his return to Martinique.
The World of Caffeine Page 36