Processing Processing Methods
Once a coffee cherry is harvested, it can be processed in a number of different ways before it is bagged and on its way to a roaster. These methods primarily vary based on region (climate, access to natural resources, etc.) but they can also be tweaked and experimented with by innovative farmers, resulting in exciting and different nuances in flavors. So, while processing methods might not sound like an enthralling topic, they have a HUGE impact on a coffee’s flavor and aroma…both of which are kind of a big deal.
Essentially, “processing method” refers to the way in which a cherry, with all of its fruity exterior gooeyness, is handled from harvest until what is left is the dried seed within. Here are the current big hitters:
Washed (or wet processed)
A washed coffee just means that the fruit of a coffee cherry was removed as quickly and cleanly as possible right after harvest. This leaves a clean seed to start the drying process. Contrary to what you may think, washed doesn’t necessarily mean washed with water. When you see a “fully washed” coffee, water was used in the process; while other types of washed coffees may have had their fruit removed by mechanical means. You’ll find washed coffees primarily from Africa, Central and South America (with the exception of Brazil), and certain Asia-Pacific growing regions.
Washed coffees typically exude bright and distinct flavors, caramel or sugary sweetness, a wide spectrum of fruit acidity, and a clean finish.
Natural (or dry processed)
At the other end of the spectrum, we have natural coffees which basically just hang out after they are harvested. These cherries are picked and then laid out to dry. After a period of time, the fruit around the seed goes from gooey to dry, at which time it is then husked or hulled off. This method is commonly used in Ethiopia, Yemen, Brazil, and Costa Rica.
Natural coffees highlight fruity or pulpy flavors, winey notes, nutty and/or chocolate characteristics, and generally have a heavier or syrupy body.
Honey processed coffees are somewhere in between washed and naturals. To put it shortly, some fruit is removed from the coffee cherry prior to the drying phase. Depending on how much fruit remains on the seed determines what color “honey” it is – yellow honey: a little fruit was on the seed, red honey: a moderate amount of fruit was left, black honey: a lot of fruit was kept on the seed. Central America, notably Costa Rica, has really showcased the majority of these yummy honeys.
Honey processed coffees exhibit fruity/pulpy/jammy flavors with characteristics of stewed fruit, caramel or toffee-like sweetness, and nutty notes.
Wet-Hulled (or Giling Basah)
Mainly seen in Sumatra, the wet-hulled process is unique with several factors at play: the region’s damp and cloudy environmental conditions, market access, and deeply rooted Indonesian traditions. After harvesting, the coffee cherry’s skin is removed (depulped) and the depulped seeds are stored in plastic tanks or jute sacks awaiting delivery to a collection point. While in storage, the fruit (or mucilage) still surrounding the seeds begins to ferment as microorganisms start to metabolize the sugars, acids, and other compounds in the fruity gooey goodness. After delivery, the coffee makes its way to a mill for hulling, where the fruit is removed and the seeds are then laid out to dry. In the wet-hulled process, the coffee is between 35-50% moisture at the time of hulling which is considerably higher than the typical 10-12% mark.
Wet hulled coffee is typically earthy, savory, herbaceous, and heavy bodied with muted acidity and predominant notes of dark chocolate and nuts.
The new kid on the block and pioneered in Costa Rica, anaerobic fermentation involves depulping the coffee and placing the seeds inside hermetically-sealed, stainless steel tanks. This oxygen-free environment affects the type of microorganisms that can survive in such a state as well as the rate in which sugars and acids are metabolically broken down in the mucilage. After an 18 to 23 hour fermentation period, the coffee is then sun dried for at least 4 hours before it continues on in the coffee life cycle.
Anaerobic fermentation processed coffees demonstrate incredibly precise and distinctly uncommon, sweet, fruity bright flavor notes (think BOLD), and exhibit a creamy, luxurious mouthfeel.
Coffees can be decaffeinated in several different ways, primarily with chemicals or without. We are big advocates of the 100% chemical-free Swiss Water Process (SWP) decaffeination method, so these are the only decafs we source and roast. For more fun reading about this fascinating process, check out our Dream On: About Decaf blog here.