Cultivation and Botany
Quality coffee in your cup… It’s a long journey where every stage counts: the soil, the harvesting of the ripe beans, the transformation of the berry, supervised at the plantation, and finally the roasting process, following the rules of best practice.
The cultivation of the coffee tree shapes the landscapes, societies and economies of many areas of the world. The mountains play a special role in this and contribute towards a quality product, more so than the plains.
Knowledge of an origin, the land and its characteristics (climate, landscape, soil quality...), the many possible combinations between the plant varieties, and cultivation and transformation methods... All these factors contribute to the richness and complexity of the product.
The culture of the coffee in 5 steps
Step 1 : the plant
The coffee tree is a plant with shiny, green leaves, which can reach a height of 5 to 12 metres and has a life expectancy of 25 to 50 years. Coffee cultivation requires fertile soil, rich in minerals, as well as a hot, damp climate. Coffee trees therefore abound in volcanic areas. There are 70 listed species of coffee trees, but only 2 are grown commercially : Robusta (Coffea canephora) and Arabica (Coffea arabica).
Robusta is grown on the plains, in areas with a hot, damp, tropical climate (tropical forests in southern Africa, India…). The plant grows in the wild and is very hardy. It produces beans that contain twice as much coffee as Arabica beans. It therefore produces very strong coffees with no aromatic variations.
Arabica is the most widely grown and traded coffee variety in the world. Due to its ecological requirements, the Arabica coffee tree thrives on high ground. Depending on the latitude and local weather conditions, it can grow between 600 and 2000 metres. Higher up, the frost and low temperatures will prevent the cherries from ripening. Lower down, it will suffer from excessively high temperatures, which are more suitable for Robusta.
Originating from Ethiopia, it is mainly grown in Latin America, as well as some countries in East Africa and Asia. Arabica trees are found in shady areas and bear fewer berries. Traditionally, producers maintained shady environments to protect young plants from excessive light, as well as the risk of frost.
In the sun, some varieties could produce large numbers of berries, but this cultivation method required a large amount of fertiliser and pesticides, and regular pruning.
Step 2 : the time of the cherries
The berries of the coffee tree look very similar to small cherries, which form after the tree has blossomed. 30 000 white flowers cover the tree when it is in blossom, and turn into berries in 24 to 36 hours. These cherries go from yellow to orange, then bright red when they reach maturity, 6 to 8 months after blossoming.
The cherry consists of:
- a red skin
- a pulp, the flesh of the berry
- a thin skin called parchment, surrounding the seed
- a second skin known as a silverskin,
- the bean, which is in fact the seed
Step 3 : harvesting
The berries must be picked when they are fully ripe and dark red in colour. The cherries on a tree do not all ripen at the same time. Following the traditional method, known as “picking”, producers have to go through the plantations several times. There are two harvesting methods: “picking” and “stripping”.
"Stripping": when the berries are ripe, the clusters are picked off whole, by hand or using machines. The branches are shaken, and the berries fall down and are collected. This is the quickest method but is less effective in terms of quality, as the berries risk being contaminated by bacteria and therefore being damaged when they hit the ground.
"Picking": we opt for this technique, which offers by far the best results and applies in general to Arabica plants which are wet processed. To collect only the fully ripe, red cherries, it is necessary to harvest them in 3 to 5 visits. This is a long, more demanding task for the pickers, but it is necessary in order to remove the pulp and obtain the best quality bean.
Step 4 : FROM HARVEST TO GREEN COFFEE
After the red cherries have been harvested, a long transformation process begins, which will result in the green coffee being ready to be bagged and sent to France, to be roasted on our site. This process requires the cherries to be rigorously sorted and processed, and quality checks must be carried out at all stages.
There are 2 ways of transforming the coffee:
This procedure requires an investment in special equipment and great technical expertise. The gustative quality of the coffees depends on it. It consists of 4 phases:
- Floating consists of soaking the cherries in a tank full of water to remove any berries with defects (not ripe enough, containing insects…). Because of their lower density, these berries will float on the water’s surface.
- Depulping is a method consisting of mechanically removing the pulp around the beans, using a depulper. The operation can be performed by the planter or at collective processing centres, which can handle amounts ranging from several hundred kilos to several hundred tonnes of cherries a day. The machines used for this operation can be operated manually or using small electric or thermal motors.
- Fermentation: the moist beans are then stored in tanks, under water or dry, for 12 to 36 hours, depending on the temperature. This fermentation stage enables the mucilage (an external layer of the bean) to decompose. Some machines can perform "demucilagination" mechanically, after depulping. However, the fermentation operation has the advantage of giving the beans certain aromatic attributes.
Washing: an operation consisting of soaking the fermented coffee in water in order to extract the residues of the broken down mucilage. It is generally carried out in canals built along a slight incline to enable the water to circulate, while the bean is tossed around by the producers. This method also makes it possible to select beans according to their density.
The higher quality, denser beans move more slowly along the water. Classic wet processing methods use a lot of water and the high concentration of sugar and cellulose of the waste products is particularly bad for the environment. Special care must therefore be taken over recycling the pulp (in the form of compost) and processing the washing water (known as effluent), which must never be thrown into the waterways.
These aspects are particularly tightly controlled by organic certification agencies. The most affordable wastewater treatment systems for producers consist of building several wells to decant and absorb toxic residues. An initial “filter well” can, for example, be filled with porous stones (such as pumice stones), with the water then being directed towards a second sedimentation well or ideally towards a pond surrounded by plants that tolerate this kind of residue and are able to feed on it.
- Drying: the washed, moist parchment coffee is dried on drying racks or concrete slabs. Once dry, it achieves a certain stability which enables it to be transported and traded.
This is the simplest technique, used for most Robusta and some Arabica coffee cherries. The cherries are spread out in the sun for 3 to 4 weeks, on drying racks or drying areas. The producers will then turn them over and toss them regularly so that the whole surface benefits from the heat, until the pulp dries and forms a kind of husk.
STEP 5: PACKING AFTER THE HARVEST
This step consists of removing the last skin from the coffee bean (the parchment) before it can be exported: this is the green bean. It also consists of sorting the beans by density, size and physical appearance (colour, shape...), before packing them into bags for export (from 60 to 70 kg).
The beans are packed according to the type of quality required by buyers (a greater or lesser number of defects may be tolerated) and therefore requires a thorough knowledge of the market. In addition, it requires relatively expensive equipment, which is only worth the investment if a certain minimum number of volumes can be processed.
For all these reasons, in many countries, planters sell coffee in dried parchment or husk form (depending on how they choose to process it after the harvest) and this final processing stage is carried out by traders or exporters.
This phase represents a large share of the added value of the exported product (20 to 35% depending on the country). Mastering this phase is therefore an important part of the production chain, in particular for producer organisations.