I Love Coffee
Coffee is cultivated in tropical areas at altitudes that range up to 6,000 feet (1,800 meters). The best temperatures for coffee cultivation are from 65° F. to 75° F. (18° C. to 24° C.). Coffee trees generally grow best in fertile, well-drained soil and in moist air. The coffee trees are susceptible to injury by insects, especially by locusts, thrips, mealybugs, and the coffee borer, also called broca ("coffee plague") in Brazil.
The trees are propagated from seeds or from the end of a living tree branch, which has been bent down and buried. The buried branch sends up a new shoot that grows into a tree. If started from seed, the young trees are often grown in shaded nurseries and then are transplanted to the fields in the shade of other trees. Within a few years after being transplanted, the coffee trees form a dense patch of growth. As they grow, they require more sun, and the shade trees that protect them are extensively pruned.
Coffee trees may bear fruit by their third year, but full bearing capacity is usually reached when they are 5 or 6 years old. They continue to produce for an average of 25 to 30 years, but most growers replace them after 12 to 15 years to maintain quality and high yields. The average tree produces 1 1/2 to 2 pounds (0.7 to 0.9 kg) of green coffee beans in a season.
In most coffee-growing countries, berries are picked by hand. In some areas they are plucked by the handful when most of them are ripe, with perhaps a second clean-up pick afterward. In other areas, picking is selective, with many return visits to each tree to take off berries as they reach full ripeness. Selective picking yields better grades of coffee beans. In any one area, picking is highly seasonal, but different areas within the same country may bring in their harvests at different times of the year.
Preparation of Coffee Beans
Coffee beans are removed from the berry by either the dry process or the wash process. The dry, or natural, process is older than the wash process. It is used in Brazil, in Angola, in the Near East, and wherever water is scarce. In this process the berries are spread outdoors on cement floors or raised platforms to dry. They are turned frequently to receive sun and air. Machine drying is also used. After being dried, the berries are run through a hulling machine, which removes the husk, the dried pulp, and the now brittle parchment. Another machine is then used to remove the silverskin.
In the wash process a pulping machine breaks open the berries and squeezes the beans from the pulpy mass. The beans, with some of the pulp adhering, are then dumped into a large tank and are left to ferment for about 12 to 30 hours. During this period the jelly-like pulp, called honey, is loosened. The honey is removed from the beans by washing them in canals filled with running water. Then the beans are dried outdoors or by warm air circulating in perforated drums and are hulled and polished by machines. Some growers employ workers to inspect the coffee and remove imperfect beans before bags are packed for shipment. Electronic devices that eliminate off-color beans are also used. In most countries, coffee is packed for shipping in 60-kilogram (130 pound) bags.
Roasting not only gives coffee its brown color but affects the natural oils that give coffee its aroma and flavor. The degree of roasting depends on popular taste and varies from place to place. Many modern roasters roast the beans uniformly for about five minutes at 500° F (260° C). About 16 percent of the weight of the green beans is lost in roasting.
Grinding and Packaging
Coffee beans are sometimes ground by consumers in stores or in home coffee mills. Commercially packaged coffee is ground immediately after being roasted. The beans are fed through steel rollers that crack and cut them to the required degree of fineness. Different kinds of brewing devices require different grinds of coffee. In the United States commercially ground coffee is usually available in three kinds of grinds: regular, drip, and fine. After being ground, coffee must be used immediately or it must be packed in sealed metal cans or other airtight containers.
Kinds of Coffee
Commercial coffees fall into three general classifications: Brazils, which are arabica coffees from Brazil; milds, which are arabicas from other countries; and robustas, which are mainly from Africa. In price and quality, Brazils fall between the milds and the robustas.
Coffees of Africa, Asia, and Central and South America are often designated by the names of areas where they are grown, such as Medellin in Colombia and Tachira in Venezuela, or by the names of the ports from which they are shipped, such as Ambriz in Angola and Victoria (now Vitoria) and Santos, both in Brazil. Other distinctions used by growers and coffee merchants refer to the hard or soft flavor of coffee beans, to the size and appearance of the bean, and to the processing of the beans.
Coffees are bought primarily on the basis of taste and aroma. The art of coffee tasting requires years of experience. Less than a tablespoonful of coffee brewed from carefully measured ingredients is used by the professional taster. The coffee is forcibly sucked in to spray the palate and is then spit out. An experienced taster can grade as many as 3,000 samples of coffee in a day.
There are three kinds of instant, or soluble, coffee: dried, or dehydrated; liquid concentrate; and frozen concentrate. Dry, or powdered, instant coffee is made by spraying liquid extract into the tops of tall cylinders, some of them 80 feet (24 meters) high. As the drops fall, they dry in a flow of hot air. Freeze-dried coffee, a kind of instant coffee developed in recent years, is prepared by dehydrating liquid coffee at low temperatures in a vacuum chamber, leaving granules of coffee. About one out of every three cups of coffee prepared in the home is made from instant coffee, chiefly dried coffee.
The taste and flavor of espresso is stronger and sharper than the blends commonly served in the United States. The coffee beans used for espresso are roasted longer and are ground more finely than beans used to prepare other coffees. Espresso is usually made in a large urn. Pressure inside the heated urn forces steam and hot water through the particles of coffee. The brew drips out of one of the machine's several faucets into a small cup. It is served black.
Caffeine is removed from some coffees by steam or by chemical soaking treatments. About 4 percent of all ground and soluble coffee consumed in the home is decaffeinated.