Coffee is a member of the family coffea of the genus Rubiacea, first grown in Africa, and now in Southeast Asia, South America, and Central America. The coffee plant grows as evergreen bushes with shiny, dark green, and spear-shaped leaves. When fully grown, a coffee plant can reach to a height of fourteen to twenty feet. However, the commercial coffee plants are rarely allowed to grow to their full height, as they are pruned and trimmed routinely. Tropical climate is one of the most important elements for quality coffee. The soil must be rich in potassium and other nutrients, and the plantation must have a good drainage. Shade is important for coffee; hence shade-plants are coexistent in a coffee plantation. Therefore, a plantation is also a good source for timber such as teak, rose, sandal, silver oak, etc. Spices such as cinnamon, pepper, cardamom and innumerable fruit trees such as orange, mango, vanilla, lemon, jackfruit, avacado, papaya, grapefruit, banana, guava, pomegranate, and sapote are conducive to be grown in the nutrient rich environment of a coffee plantation.

Coffee blossoms

Photograph by Revathy U. Chottekalapanda

The coffee plant produces a red or purple fruit, the “drupe” that has two seeds, also called the “berry” or the “bean” (though coffee is not a bean). A few berries are sowed in small plastic bags, and the stronger ones that grow into plants are then re-planted. Although there are different species of coffee plants, they can be broadly classified as the Arabica (from Ethiopia, known since the pre-historic times) and the Robusta plants (from Congo, known since 1898). Robusta is more resistant to disease and needs less maintenance than Arabica and hence popular among the farmers. The Arabica plants normally grow at altitudes of 1600 to 6000 feet and produce coffee beans after five years of re-planting whereas Robusta can grow at altitudes of about 1500 feet or less and can be harvested in two to three years. The beans in higher altitudes mature in about six months, at least two to three months faster per cycle than those grown in lower areas. The mature trees produce coffee for about fifteen to twenty years. Coffee obtained from higher altitudes are preferred since they are well-flavored. The flavor of Arabica is more popular in the Americas, but the strong coffee lovers in Europe prefer Robusta. Arabica is more expensive and used for blending.

The intensity of the rains decides the fate of the coffee crop. Initial showers called the pre-monsoon showers are required for the coffee flowers to bloom. For supplementing blossom showers, irrigation/sprinkler systems are employed. The blossoms are white clusters of flowers formed at the base of the paired leaves as white tufts where the berries form. Tufts have eight to fifteen elements and each element comprises five to six petals forming a bunch that illuminates the whole plantation, and imparts distinct contrast and beauty against the dark green background of the coffee shrub/tree. The shape and scent of the coffee flowers resemble that of jasmine and hence the coffee tree was called “Arabian jasmine” in the sixteenth century. The blossoms bloom for a few days and they wither when fertilized, and soon after more flowers appear. It is not uncommon to see leaves, flowers, and berries at the same time. As the blossoms dry and darken, the tiny green coffee beans/berries appear. The beans are small, hard, and dark green to begin with and then they grow in size, and the ripe berries turn red and crimson like a cherry. They are then picked, sun-dried, de-skinned to get out the beans, roasted, and then powdered, giving the form which we all are familiar with. The coffee picking begins in November with Arabica harvest and goes on till March since the Robusta beans ripen later. Coffee harvesting is labor dependent. There are two methods of harvesting: i) hand-picking, where berries can be sorted in parallel, and ii) shaking, where berries are stripped off by shaking the tree.

A good cup of coffee depends on good roasting. Today we enjoy coffee in many forms. Espresso, the darkest roast of the Arabica bean, formed by forcing hot water through finely ground coffee under high pressure. The others are Cappuccino, Ristretto, Latte, Machiatto, Mocha, Aulait, and Coretto with a shot of brandy or liquor. Ancient among these are the Arabica-derived Mocha and Java that are roasted for a short time before brewing. For most part of its history, coffee roasting was part of a cottage-industry. In 1864, Jabez Burns invented industrial coffee roasting to meet the increasing cost and demand of coffee. In 1900, when gas replaced coal and when heat became more controllable, he modernized his invention with the “thermalo process” by blowing hot air at high speed through the roasting cylinder. Heat is applied evenly to the bean at the lowest temperature possible for shortest periods of time, and the beans are cooled quickly after roasting. Temperatures range from 380°C for lighter, 400°C for medium, to 420°C for darker roast, where high temperature burns the bean and too low temperature bakes the bean. The caffeine component of coffee does not vary significantly with roasting, although coffee acidity is highest with lighter roasts. Coffee roasting shrinks the bean to about 12-15% in weights for darkest roasts, but doubles the volume as the beans crack and expand. The darker the roast, the greater the volume of coffee is. Some coffee beans taste better after aging (three to eight years) as acidity reduces.

Fresh air is a true enemy of coffee, so storing your beans in the controlling chamber of a freezer is ideal to restrict contamination from unwanted flavors. Watch out! Freshly brewed coffee stays flavorful and aromatic for only an hour. ◉

References:

http://www.nationalgeographic.com/coffee

http://www.coffeeresearch.org

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