After the cherries are plucked from the branch at the peak of ripeness, they find their way to the mill. Each mill is unique, operating with different techniques and equipment. Community co-ops, families, and sometimes just a few individuals run a mill. Some use relatively costly tools like parabolic dryers, fermentation tanks, high-volume sorting and hulling machines. Other mills utilize traditional manpower and natural resources to process their coffee. But all techniques are aimed at producing a viable final product and all are valid ways of producing outstanding coffee.
There are a few main ways coffee cherries are processed: the wet process (washed), the dry process (natural), and the pulped natural process (honey).
As a refresher, the coffee cherry is comprised of several layers. Moving from the inside out, it goes as follows: bean, silverskin, parchment, pectin layer, pulp, and the outside layer (skin) of the cherry. By the time the cherry arrives at the mill, we are at the point of getting down to the core—going from a red ripe cherry to green coffee beans ready for export.
The idea of the washed method is to remove ALL layers of the cherry from the bean. Without the flavors of that cherry, what remains is solely the inherent flavors of the bean itself. Washed coffee aims to bring the essence of the bean front and center.
After arriving at the mill, the cherries are “pulped,” removing the pulp and the outside layer of the cherry from the rest. The remaining bean then undergoes a period of controlled fermentation to encourage remaining tissues to separate from the bean. Sometimes cherries are soaked in water over a period of hours or days. Alternatively, after resting through a fermentation period, some mills choose to mechanically scrub down the beans rather than soaking.
After this rather intense and detailed process, the bean must be dried. Every mill has its own method of drying the beans. Some have large cement patios that have direct sunlight. The beans are attended to regularly and are flipped over with large rakes to even the drying process. Other mills employ parabolic dryers that loom over tracks of raised beds in a greenhouse-like setting. Many use combinations of these methods depending on the coffee, and still others have entirely innovative approaches to the process. Whatever the method, atmospheric conditions and rigorous human attention are of utmost importance. Drying typically is complete between seven and ten days, and the beans are then hulled, sometimes polished, weighed out, bagged, and sold.
Washed coffee benefits from a notable consistency. Defects are sorted out at several points throughout the process, and because the cherry is removed, there is nothing masking the flavors the bean possesses. The naturally occurring acidity and sweetness can come through with every complexity and nuance available to the palate.
Most of Metric’s coffee selections are washed, with our latest release being the Xenacoj y Pichol from Finca El Pilar in Guatemala. Producer Juan Carlos Chen specially processed and selected two lots and united them into blend that reminds us of toffee, dried fruits, and candied nuts. The careful attention to processing ensures that every cup is crisp and clean, and highlights the incredible quality of the bean.