Mokate
Cultivation and harvest of cof
Coffee is a fruit of a bush in the Rubiaceae family, Coffea genus. Even thought it belongs to a family of ten species of this genera, coffee lovers are really interested in just two of them: Coffea arabica and Coffea canephora, i.e. Arabica and Robusta. Arabica constitutes three fourths of the world production of coffee. In comparison to Robusta, Arabica is much more resistant to hot climate, pests and diseases, especially the so-called coffee rust – Hemileia vastatrix, which once totally destroyed a whole coffee plantation in Ceylon, making room for tea. Preventing coffee rust is much easier in high altitudes, which explains the localization of Arabica plantations above 900 m above sea level. This however means higher costs of cultivation, which translates into higher market prices, but also into higher quality.
Coffee has dark green, shiny, leaves, growing in pairs, with an oval or lance shape, and delicate, white flowers, also growing in twos or threes. Fruit appear after 4 to 6 years after planting. In case of Coffea canephora, pollination is necessary, whereas Arabica flowers are capable of self-pollination. The fruit growing in the pollinated flower's ovary, about fifteen millimetres in diameter, looks like a cherry when it ripens. The cluster is enclosed in a thick outer skin, covered with pulp. The beans enclosed inside are protected by a thick layer of whitish colour. Underneath it is a thin shield, called silver skin, which covers each of the two seeds.
Coffee bushes are cultivated in the tropics, where the seasons are not distinct. Plants flower about a week after each rainfall. If it rains eight times during the year, the plant blossom eight times, if it rains twice, blossoming takes place twice. For this reason, planters are forced to harvest after each rainfall.
Robusta matures in 9 – 12 months, Arabica in 6 -8, so at the same time, one plant can have flowers and ripe fruit. At the end of blossoming, the flower is pollinated and a fruit appears. Initially green, it eventually yellows and then becomes red. If it were to remain on the bush, its outer skin dry out, become brown and eventually fall off. This was once the method of picking coffee. Nowadays, and in periods when there is not enough water to use wet technological processes, only dry fruit which falls off by themselves is collected from the ground. However, the most refined, expensive system of harvesting is picking, which means repeatedly, manually harvesting only ripe fruit. On the other hand, stripping means selecting an optimal harvest time, when most fruit are ripe. At that moment all beans are collected, including those which have fallen on the ground. A single person is able to collect 50 -100 kg of coffee fruit, from which 10 -20 kg of coffee beans are obtained.
Even though Arabica and Robust seeds are very different from each other, it would be hard for an average amateur to tell the difference between them. Unroasted Robusta bean is more round. With a lighter, green colour, and a shade of blue. On the other hand, Arabica has flat beans with a grey or brown coating. Robusta contains almost twice as much caffeine and Arabica. Of course, it is reflected in the taste – making Arabica mild and aromatic, and Robusta spicy and distinctive.
Coffee shells are removed using two methods – dry and wet. The dry method is the older one: fruit is spread on mats and left to dry in the sun for 2 -3 weeks. Beans are often turned in order to be dry out evenly and to prevent the fermentation process from starting. Next, beans are thrown into special hulling machines which remove the dry shell. This method requires rainless weather, and since it was used in East India, it has been called the East Indian method. In regions where precipitation makes it impossible to dry grains in the sun due to frequent rains, wet method is used. However, in order for wet processing to take place, fruit have to be collected using the picking method, to be uniformly ripe. During the 12 -24 hours after the harvest, skin and pulp need to be removed using a machine which separates coffee beans from the outer skin. It is very important to maintain appropriate time intervals, because separation done too late may damage the bean. Another stage is the removal of the silver skin which doesn't dissolve in water. If it were not removed, it would cause the bean to spoil during the drying process. This is achieved during fermentation, mandatory for coffee processed using the dry and the wet method. In order to do this, beans are soaked in water where self-fermentation takes place. After a day, the skin softens and it can be easily removed under a stream of water. Beans cleaned this way should be dried so in the end their moisture content does not exceed 12%.
Drying can take place using the natural method (as in the dry method, where beans dry on mats) or in special machines. Natural drying is considered the best for coffee's quality and is used whenever the climate allows it. Depending on the temperature, this process can last from one to three weeks. Beans must be turned, maintaining appropriate moisture content is of the utmost importance. Too dry – the beans will crack when pressed, too wet – they will destroy the whole harvest by spoiling. Beans are segregated according to their size, and then sorted according to weight. The premise is that the larger the bean is, the better the coffee. Coffee cleaned using the wet method is considered to be the best grade of coffee, and it is the most expensive.