A Basic Guide to Coffee Processing
Post-harvest coffee processing such as natural, honey, etc., can seem like an overwhelming and confusing subject. This page is here to explain and simplify what processing is all about.
It's important to note that like many other things in coffee, there is no standardized vocabulary, and the same process may have different names in different countries of origin. The choice is ultimately up to the producer - we honor their decision when describing our roasts.
First let's define what processing even is.
When coffee is harvested, it's covered in a (usually red) fruity flesh called mucilage that needs to eventually be removed from the seed inside - that seed is the bean you know of as coffee. The processing step varies and ultimately includes everything from harvest to export.
Washed/Fully Washed/Wet Process - This is a very common method, and if none are listed, most likely the coffee is washed. Simply put, the coffee is put through a de-pulping machine that mechanically removes the skin and much of the mucilage. It's next put into tanks of water and allowed to ferment for 12-36 hours - this step helps to break down the remaining flesh rendering the coffee ready for drying. The result is a very clean tasting coffee.
Double Washed - Like the name implies, double washed is the same as washed but performed twice, leading to an even cleaner cup. Both washed and double washed are criticized for being water-intensive leading to the development of more sustainable methods.
Natural/Dry Process - After harvest the coffees are laid out evenly in a single layer to dry with the mucilage still intact. After roughly two weeks drying, the coffee seed is ready to be separated from the dried fruit in a de-hulling machine. The result on the final flavor is huge and largely depends on the care put into removing coffee seeds that are not drying well. A carefully produced natural has additional flavors like red wine, spice, and citrus, as well as more sweetness and acidity.
Pulped-Natural/Honey Process - This is the "Goldilocks" process that sits between washed and natural. You may also encounter more precise designations, like white honey, yellow honey, red honey, and black honey; these represent the amount of mucilage left on the bean, from least to most. Ultimately, the coffee is dried with some mucilage still intact, leading to a range of flavor profiles ranging from "basically washed" to "basically natural." We love to use these coffees for the base of our espresso because they add a lot of body and complexity simultaneously.
Anaerobic/Lactic/Acetic Process - Freshly out of "experimental" stages, these processes can now be found a bit more easily. Essentially, the fermentation stage is manipulated by introducing specific bacteria (or conditions that favor specific bacteria) instead of whatever happens to grow naturally. Using beer as a reference, think ales vs. lagers, vs. sours. These processes hugely impact flavor, usually adding big flavors like cinnamon, apple, red wine, as well as acidity.