Coffee is the seed of a cherry-like fruit. Before it is roasted, it must be grown, picked, pulped, processed and dried so we can do our best to turn it into something delicious and consumable. Below, we’ll discuss the methods used to process the seeds of the coffee fruit and how they affect the flavor of the end product.

 

Washed Process

“Washed” is a general term for coffee that has been pulped then cleansed of the sticky fruit, or mucilage, before being dried to an appropriate and stable moisture level. This can be done by mechanical means but more often is achieved by some amount of fermentation, letting naturally occurring bacteria and yeast eat the sugars followed by a rinsing in channels of clean water. There are many different variables that affect the fermentation process, including temperature, humidity, sugar content of the coffee itself, pH and of course time. Achieving a balanced and effective fermentation of coffee requires both the ability to balance these factors and the courage and artistry to manipulate them to produce a desirable result.

In general, great washed coffees are clean, complex, nuanced with crisp acidity.

 

Natural Process

Also called “sun-dried natural” or “dry process,” these coffees are the foil to traditional washed coffees. Coffee cherries are picked, and left to dry in the sun with the fruit in tact… skin and all. Great care must be taken to turn the coffee as it dries to make sure moisture leaves evenly and mold or unwanted fermentation doesn’t occur. Once the cherries are sufficiently dry, the skin and fruit is hulled away. Once only practiced in certain parts of Ethiopia (and viewed as inferior to washed coffee due to more frequent defects and sorting difficulty), the art of drying coffee in the cherry is making great strides in precision of process, the care taken with each lot and is finding great promise in many coffee-growing regions of the world.

Great natural process coffees tend to be less subtle than their washed counterparts… they are often fruity, jammy, unapologetically sweet and can serve as a “gateway” coffee for someone who has always assumed they didn’t like coffee because they’ve only tasted low-grade commercial product.

 

Honey Process (pulped natural)

In Central and South America, the Spanish word for “honey” is used to describe the sticky mucilage that surrounds the coffee seed after it is pulped. The Honey Process refers to the practice of pulping the seed out of the coffee cherry, and letting it dry with some amount of sugary mucilage still surrounding it. This can be done to varying degrees, and is a delicate balance between working with the variables and conditions present and achieving a particular end result from the coffee. Often, honey processed coffees will be given some second classification either how much fruit has been left on the seed or how frequently the coffee is turned while drying, many times described in terms of color… from “yellow honey” all the way to “black honey.” There is not, however, a standard usage for these variations or their terminology. In short, “red honey” could mean something different to any number of coffee producers so it is best to seek clarification when dealing with honey process coffees.

Honey process coffees, like naturals, are usually sweet but slightly more complex in their character, with rounded acidity and silky or creamy mouthfeel.

 

Lactic Fermentation (washed variation)

A kind of subcategory of washed coffees, Lactic Fermentation coffees are processed in the traditional washed method but placed in conditions that will specifically allow Lactobacillus to be prominently present. A method engineered by our friends at La Palma y El Tucan in Colombia, high concentrations of the bacteria are achieved through keeping high temperature, low pH and limiting the availability of oxygen. The result is the production of lactic acid as a byproduct of fermentation, which has unique effects on the flavor of the coffee.

Lactic Fermentation coffees tend to be bright with complex fruit tones, layered sweetness, milky mouthfeel and wine-like aftertaste.

 

Acetic Fermentation (washed variation)

Another tweak to the traditional washed process by La Palma y El Tucan, variables are monitored and controlled to allow proliferation of Acetobacter (acetic acid producing bacteria) during fermentation. In an oxygen-rich environment, these organisms can flourish, and the production of acetic acid during the process has a direct effect on the coffee’s flavor.

Acetic Fermentation coffees are full of soft fruit flavors, have structured acidity, juicy or tea-like mouthfeel and a clean finish.

 

Wet-Hulled Process

Wet-Hulling is a processing method unique to Indonesia. Called “Giling Basah” in the native Bahasa language, wet-hulling is the process of milling the outer parchment layer off the coffee seed while it is still at a high moisture content. Usually, farmers will pulp the coffee seeds out of the cherry and let it ferment overnight to break down the mucilage surrounding the parchment. They then deliver the coffee to a mill and it is hulled with the seed still swollen with water in the parchment. Because the coffee is still soft at these high moisture levels, the milling process deforms the shape of the seed and can often lead to many defects in the coffee. But done with care, this unique method can produce one-of-a-kind coffees that are quintessential of great Indonesian coffee.

Wet-Hulled coffees (when well-cared for) are often earthy, with mild acidity, herbal flavors, dark fruit tones and sweetness like ripe bell peppers.

 

Kenyan Process (washed variation)

Also known as “double fermentation” or “double soak”, the Kenyan style of washing coffee is unique and characteristic of coffees from the East African country. Coffee is pulped then fermented for 12+ hours depending on climate conditions and other variables, and then rinsed in water channels to clean the mucilage from the seeds. The coffee is then fermented again for 12 – 24 hours, and rinsed again before drying on raised beds.

Kenyan process coffees are usually crisp, with bright citrus and berry acidity, full mouthfeel and sugary sweetness.

 

This is by no means an exhaustive list, as there are countless variations to these processes and new techniques being explored and implemented even as you read this. But many of the coffees you encounter (especially from us) will fall into one of these categories. We challenge you to taste coffees processed in as many ways as you can, and see what the effects are on the cup for yourself!