The Cultivation Of Coffee
For almost a thousand years, mankind has been enjoying coffee. Today, coffee is more popular than it has ever been before. Even though, cultivating and drinking coffee come with important traditions in many cultures, the growing and harvesting of coffee has changed drastically since the age of colonialism. There is a complex and well-adjusted process behind every single espresso bean.
Coffee Plants Like Summer
Almost all varieties of coffee thrive best in tropical and subtropical climate zones with sufficient downfall and evenly balanced average temperatures of 18 to 26 °C. Particularly the arabica plants prefer elevated areas, explaining arabica often being called „mountain coffee“. The elevated areas enable the less resistant and robust arabica plants to grown freely without the influence of most of the vermin. Planting, pruning and harvesting often becomes considerably more difficult the higher up in the mountain ranges the plants are cultivated though, often resulting in a higher price for arabica coffees compared to robusta plants in the lowlands.
The so called „coffee belt“ is found in the tropical areas around the equator, roughly between 23 degrees of northern and 25 degrees of southern latitude and contains about 80 coffee producing countries. Different areas providing diverse environmental circumstances produce large varieties of different coffees, weather it is blue mountain coffee from Jamaica, the famous Kopi Luwak from Indonesia or Himalaya-coffee, all of them resemble product of their very unique surrounding and hundreds of years of local coffee traditions.
The journey begins with raising saplings. Carefully selected green coffee beans are loosely covered with fertile soil and irrigated with lots of water. After a couple of days, the young saplings, called „Soldatjes“ sprout from the soil and move from their nursery to the actual plantation after about one year. Sometimes, parts of a fully grown coffee plant are cut off and put back into the ground to regrow as seedlings. This ensures a particularly pure reproduction of the plant without any genetic changes. Often, other plants like banana or pepper trees are planted across coffee plantations to shade the light and heat sensitive coffee plants and to create a healthy and more natural diversification. These trees are called „coffee mamas“ and are used in the same way for tea plantations.
After about three to four years it starts paying off to harvest the shrubs, the maximum efficiency is reached at the age of about ten years. The plants will be kept at about two to three meters of hight for their whole life to ensure easy pruning and harvesting. After about twenty years the first plants will start to lose their fertility and produce and will have to replaced by new plants.
Because coffee plants are usually cultivated in tropical areas with very balanced climate, the seasons normally only differ very slightly. Therefor, the flowering period and the fruits resulting from it, don not depend on the season but on heavy rainfalls. This behavior of the coffee plants sometimes causes server damages to the coffee industry at times of drought, then resulting in rocketing world market prices of coffee. The coffee plant will start blooming about two to three weeks after a proper rainfall, even if it is raining 10 or more times in one year. Because, depending on the type of plant, it will take six to nine months until the flowers and ovary ripe into coffee cherries, at all times cherries and flowers in all kinds of development stages can be found on a single plant. Therefor a selective readout for high quality and ripe coffee cherries is only possible by the old school picking-method.
Picking and Stripping
Just as its name suggests, the picking method consists of picking the ripe coffee cherries by hand. Experienced workers will pick ripe, red cherries only and read out all faulty, moldy or damaged fruits as well as leaves and flowers, resulting in an extremely economical harvest and the highest possible quality. Because of the expenditure of human labor required for this, this coffee is more expensive than mechanically harvested varieties. At the same time, these plantations create a lot of jobs in poor countries, helping their own economy. Usually only arabica plants are hand -harvested, with a single 60kg bag of coffee cherries sometimes requiring up to one hundred mature plants to be harvested.
The stripping technique is a little bit different. About two times a year, all the coffee cherries are striped off the branches by hand. Although, during the process a lot of unripe cherries are harvested, the total coast of the harvest decreases considerably.
Since recently, harvesting machines are being used for the lowland cultivation of robusta plants. Just like during stripping by hand, all the fruit of each plant is harvested at once and sorted afterwards. For these harvesters to work, the plants have to be planted in tidy rows and be roughly the same height. While the harvester is moving over the coffee plant, a large vertical brush rotates on each side of the plant and brushes off all cherries, either catching them in a net or picking them off the floor with another brush. Especially older harvesting machines require a particularly clean floor in order to properly pick up all the fruit. Because weeds would hinder this process a lot, plantations that are harvested with older harvesters require large amounts of herbicides. The later machines simply catch the falling cherries with nets and therefor eliminates the need for unhealthy chemicals. Because both new and old machines often cause a fair bit of damage to the plant and because most of the worlds coffee is being farmed in elevated areas way too inaccessible to harvesters, the machine harvest is distributed only sporadically.
From The Cherry To The Coffee Bean
To prevent premature fermentation of the fruits, they are transported from the fields to the farm house immediately. At the farm, the unripe or moldy cherries are read out by hand or with special plants. The pulp is removed from the ripe cherries and the remaining coffee beans are dried. A distinction is made between the two most common preparation methods, the wet preparation and the dry preparation. After this, the dried coffee beans are packed into gunny sacks or bulk containers and shipped to the roasting plants. In most cases, the coffee has to leave its country of origin and take a long trip overseas to reach facilities in Europe, North America or Asia. Every cup of espresso contains a fascinating journey!
Dry „natural“ Processing
During the so called „natural“, dry processing of coffee, the freshly harvested coffee cherries are spread out on flat and ideally clean ground like concrete and dried by the sun. Therefor, countries with exceptionally moist climate conditions cannot sun dry their coffee, the cherries would simply start to rot. To prevent fermentation and mold, the coffee is stirred, turned and observed on a regular basis. During bad weather periods, some farms use the aid of drying furnaces. After 3-6 days, the dried pulp is mechanically removed and the coffee beans, still surrounded by their inner skin, are ready for the roasting plant.
Through osmose, a considerable amount of the sugar contained by the pulp makes its way inside the coffee bean. This causes „naturally“ processed coffee to often show pronounced sweetness, making it perfect for espresso blends.
The wet processing of coffee cherries is called „washed“. Right after harvesting the cherries and before the first stages of fermentation, the unsorted coffee beans are separated from the pulp inside a peeling drum. Now, the beans, still covered in a protective layer of slippery skin, are flushed into large fermentation basins. Faulty or moldy coffee beans will float up and caught by a separator before the fermentation process starts. At this stage, the water and the bacteria inside of it will soften the so called silver skin of the beans to an extend that it can be washed off easily now. The cleaned beans are ready to be either dries naturally or inside of a drying furnace. Depending on the thoroughness of the washing process, the resulting beans are categorized in „pupled natural“, „washed“ and „fully washed“.