In the stages of processing coffee cherries until they finally become a cup of coffee drink, there is one important process that has a big role in the taste of the coffee produced. This process is fermentation.
What is fermentation? Fermentation is a chemical process in the form of breaking down sugar molecules into acid or alcohol which is assisted by certain microorganisms or enzymes. The fermentation process usually occurs in making food and drinks, for example in making wine or beer and food tape.
The fermentation process that takes place in coffee processing occurs at the post-harvest stage. It should be understood that the fermentation process is not a direct stage of the coffee cherry processing process. Fermentation is a natural process that occurs during the stages of coffee processing and occurs when the sugar in the coffee cherry meets water.
Fermentation is divided into two types: aerobic and anaerobic. In aerobic fermentation, the sugar decomposition process occurs when oxygen is available. This fermentation occurs in natural, honey, dry hull and wet hull coffee processing methods. Fermentation in this process occurs in open conditions and is exposed to outside air. Meanwhile, anaerobic fermentation is fermentation that occurs in conditions without oxygen. This fermentation is carried out by placing the coffee cherries in a tank filled with water which is then tightly closed so that it is not exposed to oxygen.
In the natural method, the coffee cherries that have been harvested are immediately taken to drying site. The coffee cherries are then spread out in the drying platform and dried as they are for several weeks until the fruit shrivels and turns black. At this stage, the flesh of the coffee cherry will be fermented by microorganisms (such as bacteria or yeast) on the surface of the cherry. These microorganisms will change the sugar content in the cherry flesh which will give it a wine-like and fruity taste. This taste can vary depending on the type of microorganism.
In the washed wet hull and dry hull methods, the coffee cherries will be put into a pulping machine which will separate the skin and mucus from the coffee beans. The coffee beans are then placed in a tank filled with water and left for some time. The fermentation process will take place in this phase which will break down the sugar remaining in the coffee beans. With this method, the coffee usually tastes lighter and more acidic.
In the honey method, the coffee cherries are only separated from the skin, leaving the mucilage attached to the coffee beans. The coffee beans are then soaked in water in a tank for some time and then dried in the sun. The fermentation process will take place when the coffee beans are in the holding tank and when they are drying. In the honey method, the mucilage remaining in the coffee beans makes the taste tend to be syrupy with floral or fruity notes.
The fermentation process is quite complex because there are quite a lot of variables involved in it, such as the type of microorganisms, temperature, time, water conditions, additional ingredients, and so on. This causes the taste of coffee beans to vary depending on the fermentation. The results of this fermentation play a role in creating the delicious Toraja coffee produced by Sulotco which you can get at our official online shop.
