There are three main preparation systems. Each single one can be different from country to country and origin to origin. These preparations are developing different amounts of ingredient types during the process. For the roasters it is important to know what kind of preparation the coffee goes through because they can orientate on their experience and statistics to develop a new coffee.
During the washed process, the entire pulp is detached from the seed before it dries. This processing method is very costly. After the harvest, a pulper removes the peel and most of the pulp from the seeds. Then the cherries are placed in a water tank where the remaining pulp is removed by fermentation. The pulp contains a large amount of pectin and is firmly attached to the seed, but during the fermentation it extent that it can be washed away. The amount of water used depends from producer to producer and in some opinion the process is harmful to the environment because the water is polluted. Fermentation depends on several factors such as altitude and ambient temperatures. The warmer it is, the faster the fermentation takes place. However, if the mixture is left to ferment too long, the beans can take on negative flavors. However, there are a few methods you can use to check that the fermentation process has ended.
2. Natural / Sun dried
"Natural preparation" is the oldest method. After the harvest, the coffee cherries are placed in a thin layer. Some farmers use brick paving, others use drying tables, which improves the air circulation and thus possible drying. The cherries must be turned over and over again so that no mold, fermentation or rotting processes begin. When the cherries are dry, the skin and pulp are removed mechanically. The green coffee can now be stored and exported.
3. Pulped Natural / Honey Processed / Semi washed
After harvesting, the cherry is mechanically peeled off, removing all of the skin and a large part of the pulp. They are then immediately placed on drying surfaces or tables. The lack of pulp reduces the risk that you will catch defects, but there is still enough sugar to make the coffee noticeably sweeter and richer. However, careful drying after pulping is essential.
This preparation is very similar to the pulped natural variant and is used in Central American countries such as Costa Rica and El Salvador. The coffee is mechanically peeled, but the water consumption is even lower than with the pulped natural process. The pulper can usually be adjusted so that it leaves a certain percentage of the meat on the seed. The coffee produced in this way is called 100% honey or 20% honey, depending on the proportion of the remaining pulp. However, the higher the proportion of pulp, the greater the risk of fermentation and defects during drying.
Semi-dry processing is particularly common in Indonesia, where it is called giling basah. The seeds are depulped and briefly dried, but not to 11-12 percent moisture content as with other methods, but only to 30-35 percent. Now they are peeled, that is, freed from the parchment, so that the green bean is exposed. The drying process is then continued until storage is possible without the risk of rotting. During the second drying cycle, the beans turn a noticeable dark green. The semi-dry processing is the only method in which the parchment skin does not stay on the bean until shortly before shipping. Many are of the opinion that the earlier lead to a kind of defect, but the specific taste notes are now associated with Indonesian coffee, so that a departure from this method is no longer required. Semi-washed coffee has less acidity and more body than other types, and it also creates a whole range of other typical nuances such as wood, spices, tobacco, leather and musty and earthy touches. In the coffee scene there is heated debate about whether this is desirable or not.