A Quick Glance at Coffee Processing
Planting: Coffee shrubs come from actual coffee cherry seeds which, in turn, are dried, hulled, roasted, and last but not least grinded so that we may brew a cup of coffee. It takes about four to five years for a seed to grow into a shrub and bear fruit. After the shrub fully matures, the cherries can be picked and processed, thus becoming the coffee beans that make a great cup of coffee. These cherries are the seeds that are planted in large beds in nurseries. Different species (e.g. red bourbon, gesha, sidra, catuai, caturra et al) are selected according to each farmer´s specific needs. Those needs include things like soil type, production rate, and disease resistance. The seed selection is of utter importance since each variety has unique features.
At these nurseries, each individual plant is carefully provided with the right amount of water, sunlight, and nutrients while being protected against plagues, diseases, and harsh environmental conditions. Once the plant is strong enough, it is ready to be planted in the field.
Tree growth: Once planted, it will take between 3 to 4 years depending on soil conditions for coffee shrubs to begin bearing fruit. These shrubs need lots of work and maintenance including pruning, fumigating, and fertilizing in order to produce high quality beans. In addition, every 5 years shrubs are cut to allow new shoots to sprout. This process keeps coffee cherry production vigorous and prevents the shrub from growing too tall for its fruits to be hand-picked.
Harvest: Coffee cherries that turn red or close to red are ready to be harvested. The most common harvest method is to hand-pick, although a few plantation use mechanized systems. Coffee is harvested in one of two ways; Strip picked, were the entire crop is harvested at once and Selectively picked, where only the ripe cherries are harvested. To be able to selectively pick the cherries, pickers have to rotate among the trees every 8 to 10 days, picking the reddest cherries available.
Processing the Cherries: The processing of the coffee cherries should be done as soon as they have been harvested to keep them from fermenting and thus spoiling the coffee. There are two basic methods of processing coffee, each of which influences the final outcome of the coffee.
The Dry Method: It’s the oldest and most traditional processing methodology, especially in places where water resources are limited. After being harvested, the cherries are spread out on large surfaces to dry under the sun. They are raked and turned through the day to prevent them from fermenting. This is done over the course of several weeks.
- The Wet Method: Under this methodology, the pulp is removed from the coffee cherry and the bean is then dried. To do so, the cherries are passed through a pulping machine where the skin and pulp is separated from the bean. The pulp is then washed away with water. Through the use of water channels, the beans are separated allowing the lighter beans to float to the top and the heavier ripe beans to sink to the bottom.
The cherries then pass to water-filled fermentation tanks where they will remain for the next 12 to 48 hours (depending on processing method) in order to be able to remove the slick layer of mucilage that is still attached to the parchment. Natural enzymes will cause this layer to dissolve. The beans are then rinsed through additional water channels. The cherries will later be dried in a similar manner to the dry methodology.