The processing
Our story now segues into the various ways coffee is processed.
Once harvested, the drupes (the technical name for the fruits of the coffee plant) are brought to establishments or agricultural cooperatives where the actual processing is carried out according to one of several methods.
DRY PROCESSING
Natural or “dry processing” results in a surprisingly sweet and full-bodied cup of coffee that envelops the palate.
The dry process entails separating the fruit into its different components: bean, skin, pulp and parchment. First, clean drupes are selected, separating them from the overripe ones (which are discarded) and from the green ones, which are dried by spreading them out in the sun on specifically built flat concrete areas called patios, moving them several times to prevent any fermentation. This will allow them to dry uniformly and prevent the onset of mold and bacteria. Every evening at sunset, the fruit is gathered and covered with sheets, to protect it from the humidity of the night, and is spread out again the following morning using rakes. This practice is carried on for the next three weeks until the harvest is ready. This method originated in the regions between Ethiopia and Yemen, where water is scarce but there is always plenty of sunlight!
Once both the peel and the pulp are dry, a machine (either manual or automatic) is then used to shell the coffee bean, caring not to damage the delicate parchment, which is nothing more than the drupe’s inner layer protecting the bean.
WASHED PROCESSING
Another coffee processing method is the washed process. This type of processing results in a cup with a lighter body than a natural processed coffee, and gives it intense aromatic notes.
This method is mostly employed in regions defined by heavy rainfalls or located next to water basins, as processing involves large quantities of water. In fact, fruits are placed inside large vats of water where a sort of "natural selection" occurs, and ripe drupes sink to the bottom, while the unripe ones, also known as “floaters”, remain on the surface and are then removed. The ripe drupes are then passed through a machine (called Pulper) that breaks and separates the peel and pulp from the bean, the latter being sent into a second vat. Here, beans will undergo a fermentation period varying between 12 and 36 hours.
At this stage, operators must prevent over-fermentation and must remove defective beans that could risk ruining the entire batch. In the next vat, beans are cleaned to eliminate any pulp residues, carefully leaving them wrapped in their parchment: this phase is called Parchment Coffee.
Drying is the last stage in the wet process and can be carried out through in one of two different ways:
- The first is approximately ten days long and involves drying Parchment Coffee in the sun on a raised structure over beds of fine mesh so that air can circulate and pass through the beans.
- The second, instead, involves using a machine, which employs air to keep the beans constantly moving and allows them to dry in approximately 24 hours.
To obtain a high-quality product, these methods must be carefully followed, to avoid problems that could impact the following processing stages.
The main difference between “natural” and “washed” coffee lies in the number of solids dissolved into the cup during extraction. In fact, natural coffees have a greater volume of soluble solids, which is why our espresso will seem to have a fuller body.
HONEY PROCESS
A third additional processing method that has gained ground in recent years, and which is a sort of hybrid between natural and washed, is the honey process. It has become increasingly popular, especially in Costa Rica and El Salvador.
This process involves pulping the bean as with the washed procedure, but instead of being completely washed from the pulp, it ends up being dried with part of it. The percentage of residual pulp on the bean is what gives name to this process, as it lends the cup a certain unique sweetness and aromatic complexity.
- white honey: approximately 10% pulp
- golden honey: approximately 25% pulp
- yellow honey: approximately 50% pulp
- red honey: approximately 75% pulp
- black honey: almost 100% pulp.
