Have you ever noticed how much effort it takes for a skilled barista to produce your expertly crafted latte or espresso? Even your drip coffee requires careful laboring, albeit somewhat minimal. Well, it may be surprising to know that your brew requires much more labor and human effort before it even reaches the roaster, let alone the grinder or coffee brewer!

Coffee is, after all, one of the most traded agricultural commodities in the world, and it requires a great deal of human effort to make it from tree to cup. In this post, I’ll be covering a BASIC rundown (for a serious debate read this) on how coffee is processed prior to shipping to your local or regional roaster…I mean, it’s worth noting that HOW your coffee is processed affects it’s pre-roast flavor as much as where it’s grown!

Basically, coffee processing is broken down into two main categories: wet and dry, with subtle differences within these two main processes depending on the method employed at the coffee farm or plantation. Methods vary from region to region and are based on what variety of coffee is grown and the typical weather patterns during the brunt of the harvesting season. Furthermore, several ‘hybrid’ methods are developing and in use on farms today; these combine the benefits and nuances inherent in both methods all while increasing efficiency in production, increasing quality, and reducing some of the environmental impacts associated with a singular method.

Wet (or washed) Process Coffee:

In the wet process, the cherry pulp of the freshly-harvested beans is removed by using specific equipment, and oftentimes, large amounts of water. Beans are immersed and the good ones are separated from the bad before they are then mashed with screens–this separates some of the sticky pulp from the bean before further processing.

Then, depending on the method, the beans are either left to ferment in their mucilage (known as ferment-and-wash processing) under close monitoring; this ensures that undesirable off-flavors result from the fermentation. The other route is machine-assisted processing; this uses machines to ’scrub’ and remove the mucilage from the bean thereby cutting down on the amounts of wastewater and likelihood of off-flavoring that can happen from traditional wet processing.

During fermentation, enzymatic action breaks down the sugars in the mucilage and affect the development and complexity of the flavors in the final bean.

Afterwards, machines and even more water is used to remove the remaining mucilage before the beans are dried (either in the sun or in machines), further processed, cleaned, sorted, graded and shipped overseas.

Dry Process Coffee:

Also referred to as ‘natural process’ coffee, this method removes the entire cherry is dried prior to removing the cherry from the bean. It’s also the oldest method of processing coffee in use today.

The cherries are first cleaned, sorted and spread in thin layers on either patios or racks to dry in the sun.  In larger plantations, drying is done first under the sun and then in machines to speed up the process.

Once a specific degree of dryness is reached, the beans are then moved to silos for storage before blending and forced into hoppers where the entire cherry is removed from the bean. Drying, much like wet-processing, has to be closely monitored because over or under-drying will affect the quality of the bean and how easily it separates from the mucilage in the hopper.

After coffee’s processing, the finished beans are again cleaned and sorted, then graded before being bagged for final shipping.  All that work, and you still have green beans. However, flavors and nuances are developed in these stages before the skilled hands of a coffee roaster begins his or her job. Bad beans from processing will therefore result in a poor cup of coffee…no matter how talented your coffee roaster may be.

Other resources: Sweet Maria’s has a lot of photos of coffee processing in their flickr collection and there are more good basics plus photos in the Wikipedia article.