You’ll hardly see coffee processing make the headlines or in everyday coffee discussions, but it’s an integral part of coffee making. It profoundly determines the flavor and character of the coffee in your cup. But there’s more to it.
Having understood how coffee is processed, you’ll be in a better place to know what you’re ordering yourself into and which type of processing best suits your tastebuds. You may even be surprised; processing coffee is something you can try from your home.
Let’s get into the details.
What is Coffee Processing?
Coffee processing is one of the most crucial stages of coffee farming. It involves the separation of coffee skin and the fleshy fruit from the coffee bean. Processing occurs as soon as the cherries are picked to avoid spoilage.
If this is all new to you, the bright deep red ripe fruit farmers pick from the coffee plant is a coffee cherry. In the cherry, there are layers of fleshy fruit surrounding the two coffee beans locked inside. The fruit has the outer skin, pulp, pectin layer, parchment, and silver skin. Processing is required to obtain the coffee beans.
But the coffee beans aren’t the only essential parts of the coffee cherry. Many desirable, flavor-changing benefits come from pulp, fruit, or juice. Processing determines the extent to which the beneficial elements of the layers get into the bean.
Why Does it Matter How Coffee is Processed?
The coffee processing method has a significant impact on the final flavor, body, and aroma of coffee. It determines the final state of the brew in your cup by affecting the chemistry of the green beans.
The process of getting rid of the cherry layers varies across the different processing methods. Some coffee processing takes more time, others make the best use of natural resources, while others require resource investment. You want to choose the one that preserves the coffee’s natural elements the most without decreasing its value. Remember, even the highest grade of coffee can degrade under poor coffee processing.
The Main Types of Coffee Processing
There are 4 most common coffee processing methods that you’re likely to find on coffee packaging.
1. Washed/Wet Coffee Processing
The washed method is the most extensively used coffee processing method. The freshly harvested cherries are passed through a depulping machine which removes the pulp from the cherry remaining only with the beans. The beans then go through water channels while being separated by weight. After separation, they are stored in large, water-filled tanks for fermentation.
Here, the beans will sit for 12 to 48 hours to remove the slick layer of mucilage (parenchyma) that remained attached to the beans after depulping. The time it takes for the mucilage to naturally dissolve highly depends on several factors, such as the climate and altitude the coffee is grown and the condition of the beans. Once the grower determines that coffee beans are fully fermented (the beans will feel rough), they’re passed through water channels for rinsing. After this, the beans are ready for drying on raised drying beds.
While the washed method is quick and efficient, it is highly wasteful. The process requires massive amounts of water while the stations generate lots of waste. The infrastructure for this kind of processing also takes large space and uses non-renewable energy, which is wasteful.
Since the fresh is completely removed from the coffee beans in the washed method, washed coffees depend almost entirely on the natural sugars and nutrients obtained when growing. The type of soil, weather, and attitude where the coffee grows determines the flavors.
Washed coffee beans have clarity of flavor with citric-like acidity or slightly bright with a lemon-like flavor. The clean taste enabled you to taste all nuances of the variety and origin. You can taste extreme flavors in Guatemala and palatable brightness in Ethiopia and Kenya’s wet coffee.
2. Natural/Dry Coffee Processing
The dry method has been used to dry coffee since the early times and is still common in many countries, especially where water resources are scarce. It’s the most common after wet processing. Here, the freshly picked coffee cherries (everything intact) are simply spread out on raised surfaces to dry in the sun.
To prevent the cherries from inconsistently drying, which would affect their quality, they’re turned and raked throughout the day. In the night or during rainy times, they’re covered to prevent water. The time it takes to completely dry depends on the weather, but generally, this may continue for several weeks before the batch dries. The coffee cherries are ready for depulping when the moisture content drops to 11%.
Natural drying has its fair share of benefits. First, it conserves resources as it uses the sun to dry, unlike wet processing that requires a lot of water. But also, dry-processed coffees tend to have a fruitier taste and flavor and can be intense and berry-like. To most, this method produces some of the best flavors of coffee.
Over time, though, the dry process has grown to be considered a low-quality processing method since it can lead to inconsistent flavors. If an unripe fruit is dried alongside the ripe fruit, it will turn brown, but its flavor will be of low quality. Besides, if not well turned and cared for, coffee beans will become moldy and make the beans go bad.
However, if consistency is achieved, many argue that dry coffees can match or surpass washed coffee in clarity and bring out incredible cupping notes.
3. Honey Coffee Processing
Honey coffee processing, also called pulped processing, is increasingly becoming popular in countries like Costa Rica and EI Salvador. But you may wonder, why the name? The honey process, if done right, produces coffee that has a taste of honey and brown sugar. The name, however, comes after how sticky the beans are after depulping. In honey processing, ripe cherries are first partially depulped (with bits of pulp in them), then immediately placed on raised beds for slow drying.
The final coffee is then categorized as yellow, red, black, golden, or white honey, depending on how much pulp is left. The more mucilage left, the sweeter and more depth coffee will have.
To most, this coffee is between washed and natural processed coffee; it’s fruity but not as exaggerated as natural processed coffee. It has a more acidic taste than washed coffee.
4. Wet Hulled/Semi Washed
The wet hulled method starts quite similar to the washed processing. Depulping machines remove the coffee bean from the freshly picked cherry, but rather than drying the beans, they are stored in plastic tanks. In the storage, the mucilage remains with the beans ensuring they retain high moisture. Before they move to the next stage, the mucilage is allowed to form a thick husk encapsulating the seed. The beans are then hulled–removing the husk, alongside the parchment, then allowed to dry.
This processing method is used in regions with high humid climates, where drying the coffee beans is arduous. Semi washed is more efficient as it takes half time to dry than other processing methods. Thanks to the dried mucilage, the size of the dry bean is heavy-bodied, as it retains more moisture.
The taste is also rich and earthy but also brings out the chocolatey and nutty flavor. While the intense flavor with wet hulled coffee is not for everyone, its single-origin (Indonesia) offers a unique experience for any adventurous coffee lover.
Other Variations of Coffee Processing
In the past years, many countries have extensively used one processing method over the others. For instance, Rwanda, Kenya, Ethiopia, and most Central American countries have traditionally favored washed process. On the other hand, Brazil has been increasingly tending towards natural and honey methods.
Lately, however, coffee growers and processing farms are open to trying other processing methods, thanks to the growing demand for specialty coffee. Specialty coffee is of the best grade with dramatic taste. It comes from coffee being grown at the right altitude, at the perfect time of the year, in the best soil environment, and picked at the right time. Of course, experimenting on other processing methods highly depends on if the climatic and environmental conditions allow.
Additionally, there’s have been a variation of coffee processing methods springing up from the 4 main types above. The wine process, for instance, varies from the natural process in that instead of harvesting cherries when ripe, they are allowed to over-ripen, increasing their sugar concentration and slightly fermented flavor.
With the growing experimental spirit and the eagerness to create better flavorful coffee, you can expect to find even more variations in the future.
How to Process Coffee Beans at Home
As you’ve seen from the coffee processing methods above, it takes massive effort to process coffee. It’s possible to process coffee beans at home, but it will take immeasurably hard work and time, especially without the right equipment. In that case, it may not be possible to process a significant amount of coffee beans as you’d like.
However, if you’re up for the adventure and a slightly tedious experience, go for it.
Here’s a simple wet process to get you started:
- Remove the beans from the fruit: You may need to get creative here. Use a steak knife, or crush and grind the fruit with a heavy thick board or concrete. You can also soak the beans overnight to loosen the pulp (fruit) from the bean. You also have to deal with the mucilage (slimy substance covering the bean).
- Soak the beans for a day or two: This will dissolve the slimy layer. Remove the beans once they feel rough, and rinse.
- Dry the coffee beans: Leave the coffee beans in the sun for a few days until they are completely dry, so they don’t get mold, specifically if you want to store them long.
- Hull the parchment layer: Your beans may still have a light covering; scrap it off. To make it easier, pour small amounts into a plastic-bladed food processor, and blend on low heat for 30 seconds. Use a hairdryer to remove the lighter parchment.
Now you have your processed beans ready for roasting, grinding, and pouring into your favorite cup of coffee.
Alternatively, try any of the above coffee processing methods, and go for the one that fits you best.
Who knows, you might come out appreciating the amount of work that goes into producing your favorite cup of brew.
Does The Processing Method Impact Roasting Technique?
You want to carefully consider the coffee processing method as it determines the right roasting technique. You now know that processing affects the chemical composition of coffee beans; roasting is what breaks down the chemicals into aroma-filled compounds.
During processing, dry-processed coffee beans retain more sugars, which makes them less susceptible to heat when roasting. You want to use low heat on them as the sugar molecules can degrade to produce unpleasant flavors. The right roaster for natural coffee needs to roast in care, in low temperature, especially in the early stages.
The same special attention should also be given to honey processed coffees. Take your time; don’t rush when handling the natural and honey coffee. You don’t want to burn the very qualities you were trying to preserve. Keep experimenting and comparing results at different temperatures.
Wet processed coffees are quite different; they are more withstanding. In fact, the shorter the roast time, the more acidity they preserve. However, regardless of the coffee process type, it’s vital to control the energy you put at the beginning of the roast. It dictates the end results of your roast profile.
The different processing methods show how much processing influences the taste and overall profile of coffee. If your taste buds love the sugar and fruity notes, natural and honey coffees are your candidate. But if you desire to experience all the nuances of origin in coffee beans, wet-processed coffee will satisfy your craving. Whichever you choose, now you’re more familiar with the processing method that will create the coffee profile you desire.