What does Processing mean?
In coffee cultivation, processing refers to the steps taken to transform freshly harvested coffee cherries into green coffee beans that are ready for export. There are two main types of processing: wet and dry. Wet processing involves removing the cherry skin, fermenting the beans, washing them, and then drying and sorting them. This process results in cleaner, brighter-tasting coffees.
Dry processing involves drying the whole coffee cherries in the sun, then removing the dried skin, pulp, and parchment in one step. Dry processed coffees have a wilder flavor profile, with more body and character, and are often used for blends. The type of processing used depends on the desired cup profile, as well as logistical and economic factors. The end result is green coffee beans that are graded, sorted, and ready for export.
In addition to the wet and dry processing methods, there are also different variations and combinations of the two methods, such as semi-washed processing (also known as pulped natural or honey processing) and wet-hulled processing (also known as semi-dry processing).
Semi-washed processing involves removing the outer skin and some of the fruit flesh of the coffee cherry, but leaving some of the mucilage intact before drying. This can lead to a unique cup profile that combines some of the characteristics of both washed and natural coffees.
Wet-hulled processing, which is commonly used in Indonesia, involves removing the skin and some of the fruit flesh from the coffee cherry, allowing the beans to ferment briefly, and then removing the parchment while the beans are still wet. This process can result in a distinctive flavor profile that is often described as earthy or musty.
Another important aspect of processing is the level of fermentation. During fermentation, naturally occurring enzymes break down the sugars in the mucilage or fruit flesh, which can affect the final flavor of the coffee. Under-fermented coffee can have a grassy or vegetal taste, while over-fermented coffee can taste sour or fermented. The timing and duration of fermentation can be adjusted to achieve the desired flavor profile.
Finally, it's worth noting that processing is just one part of the overall coffee production process, and that the quality of the green coffee beans is also affected by factors such as the variety of the coffee plant, the climate and soil conditions in which it was grown, and the harvesting and drying methods used. All of these factors, along with the processing method, can contribute to the final flavor and quality of the coffee.