There are as many ways to produce good coffee as there are to produce bad ones. This is why from the farm to your cup, the processes involved are more than just a matter of measuring and machinery. It is in fact both a science and an art. Beyond roasting, there are many factors and techniques at work that enhance the quality of the coffee that you enjoy.
These precious beans take a long journey from the farm where they are planted until they end up expertly brewed in your cup. Each of the carefully calculated and artistically orchestrated step is crucial in bringing out the nuances in flavors and aromas that make coffee such a well-loved drink all over the globe.
So whether you’re an avid coffee drinker or a ritual-oriented brew master, it helps to know the different processing methods and how they bring out the best in your coffee.
Coffee Processing Methods
There are different techniques in processing coffee that are employed by farmers or producers throughout the world. These coffee processing techniques are done to showcase the coffee bean’s inherent qualities, maintain a long-held tradition, or to coax new flavors to uncover a new profile. Among these techniques, two are most dominant: natural and washed coffee processing.
Which of these methods are the best to use? Let’s find out.
Also, known as the Dry Process or the Sun-dried Method, this coffee processing technique is the oldest and most basic. Upon harvesting, the coffee cherries are sorted. Ripe ones must be picked out among the green, unripe cherries as well as any leaves and twigs that may have been mixed in. These ripe cherries are then simply put out to the sun to dry. The cherries are spread thinly on a flat surface and are raked regularly to maintain even drying and temperatures throughout the many layers of the cherry down to the bean inside.
Drying like this takes between ten days and a month. For larger coffee farms, drying is accelerated with the help of mechanical driers.
This drying process is crucial in coffee production to ensure brittle beans, which are then roasted to bring out its bold flavors. It also ensures that there is no excess moisture, which may cause the development of fungi and molds that may ruin an entire batch of beans.
Once dried, the cherry turns into a shriveled fruit. This is then stripped off using a special hulling machine. In this process, the pulp and skin are hulled so that only the seeds inside will remain. These seeds, though still green, are what will soon become coffee beans.
While the natural process produces a robust, full-bodied brew that may have subtle citrus notes, it can easily go wrong. The coffee cherry’s fruit can impart flavor to the bean in this process. Therefore, if the coffee’s moisture content has not been completely drawn out, the fruit can ferment, turn rancid, and taint the coffee’s flavor. This can translate to an “off” tasting cup.
Dry processing can be risky, especially if you are sourcing from multiple farms or origins, or if you have big precious batches of harvested coffee. Therefore, many producers and exporters choose the wet process.
Wet coffee processing takes out the cherry pulp early in the process so that it doesn’t decompose with the bean, which can cause the off flavor coffee producers avoid.
After harvesting the freshly picked cherries, they go through a pulping machine. This machine separates the fruit pulp and the thin parchment that surrounds the green coffee seeds. From here, the beans are sorted as they pass through a water channel. The lighter beans will float, while the heavier ripe ones will sink to the bottom. Then, the ripe ones are collected and passed through several rotating drums to separate them by size.
After sorting, the beans then go into big fermentation tanks filled with water. Here, they will sit for 12 to 48 hours in order to remove the mucilage layer that is still attached to the bean. Fermenting in these tanks, the beans will start to produce enzymes that will dissolve this slick layer. This mucilage may also be removed by mechanically scrubbing the beans together. Once this layer is removed, the beans are rinsed multiple times before they go to the next step, which is drying.
This next step requires the beans to be dried to 11% moisture level, on drying floors or in machine-powered tumblers, so that they can be properly stored. Once dried, these beans are called parchment coffee because of a paper-thin layer surrounding the beans.
At this point, the coffee beans undergo more steps, such as hulling, which removes the parchment. An optional process, called polishing, can also be done to create more superior beans. Finally, they are graded and sorted according to size and weight, where the flawed and defectives ones are removed either by hand or special machinery.
With wet processed coffee, since the fruit is removed at the beginning, it does not impart any flavor to the final coffee bean product. This means that the coffee gets its flavor distinctly from its origins and from the environmental conditions from which it grew. Many specialty coffee producers use this coffee processing method exclusively for this reason.
There are many other kinds of coffee processing techniques that are used by various coffee producers in different countries. Between the robust, sweet natural or a crisp, tart washed, there are different processing methods that explore a middle ground.
However, there is no right or wrong way of processing coffee. One is not better than the other. What determines the kind of process to be used on particular coffee beans rely on the beans’ inherent qualities and what method can best showcase these for the ultimate enjoyment of the coffee drinker.