Looking back to Part 1 of Things To Consider, we briefly cover variables in relation to the growing environment of coffee. Past this point is actually processing the coffee. For those unfamiliar with the term “processing,” this term refers to the method used to remove the green coffee seed from the coffee cherry.
Natural Processed Brazil, raw green coffee on the left, and roasted coffee on right.
Dry/Natural Process - The dry/natural process is most common in areas where rainfall is scarce. The process starts with picking the fruit from the tree. Though this seems simple, this is a vital step in the process even though it is the most basic, more on this later. Once all of the ripened cherries have been picked they are then laid out on drying patios for the sun and the heat to dry out the entire cherry. Occasionally they will be raked throughout this phase as to maintain consistency. Once the cherries have dried out to a slightly reddish shade of black, they are sent to hull off the dried outer layer, exposing the green bean. Although this type of processing requires minimal resources, it is very much a hands on job and produces inconsistencies amongst coffee seeds. Typically, one could expect dry processed coffee to be sweeter with a heavier body, and sometimes will be layered with fruit notes.
Washed Processed Ethiopia, raw green coffee on the right, and roasted coffee on left.
Wet/Washed Process – The most common method for processing coffee is known as the washed, or wet process. This type of processing produces a cleaner mouth feel and typically results in higher acidity. Although the process itself varies in many ways from country to country, or even from station to station the result is more consistency amongst coffee seeds. The process starts itself starts by picking cherries at the tree, again trying to pick consistently ripened cherries. The cherries are then sent through a pulper to remove the skin and mucilage of the fruit. What is then left over is the seed still protected by the husk, wrapped by a thin but resilient layer of mucilage. Removing the final stubborn layer of mucilage, the seeds are first fermented in tanks, and then sent through washing channels where the seeds will be agitated to remove any mucilage that remains. From this point the seeds are dried (still in parchment) on patios, turning over occasionally so that the seeds lose the correct amount of moisture uniformly. Finally the seeds are passed through a hull to remove the husk. At this point is where we recognize the green coffee bean/seed. Washed processed coffees typically have a cleaner mouth feel with higher acidity.
Pulped Natural – Pulped natural coffee is somewhere between Dry and Wet processing of coffees. As with the other processes, we start at the tree by picking uniformly ripened cherries. We will start to follow the same procedures as the wet processed coffee by sending the coffee through a pulper to remove the skin. From here is where we deviate from following the washed process to following the dry process. The mucilage is left on during the drying stage, where the coffee is left out on drying patios or raised drying beds in the sun, very similar to the dry process only without the skin. It is then sent to the hull to remove the remaining mucilage and parchment. Pulped natural coffees are usually sweeter than washed coffee, but maintain a higher acidity than dried coffee.
Other types of processing do exist, albeit they are slight deviations of the aforementioned.
Ripeness from the source - This is crucial to the consumer’s review of the cup. If the cherries are picked in all sorts of stages during ripening, then the processing will be inconsistent, as will be the green coffee seeds, as will the roast. Finally the extraction will be inconsistent amongst the coffee seeds that are used to brew your coffee at home will not taste the way it was intended to.
There are many systems put in place during processing to minimize the amount of black beans, incorrect ripeness and any other inconsistencies that may exist from the lot. This is not a perfect system; some seeds will still get through. Brewing a large pot of coffee with one unripe bean that was roasted and is now an uneven roast may not be noticed. But scale that down to a single cup pour over and maybe two unevenly roasted beans are present and it will be noticed.
At this point we have just about reached the final stages at origin. Regardless of processing, the “beans” will be packed into jute sacks following the processing and sent to ports. Then sent across seas to Europe, Japan, Australia, United States and many more countries.
Part 3 of this series we will follow the journey of coffee as it is supplied to the roaster, and what our jobs are here in the roast house.