Washed coffee processing – Usually, when and before coffee producers sell their coffee beans, there are 3 primary information that must be presented without exception: the roast profile, flavor notes, and processing method.
The post-harvest processing of coffee is undoubtedly the longest and most crucial process. Quoted from sagebrushcoffee.com, it is mentioned in a brief description that a processing method refers to the technique used to transform a ripe coffee cherry into the green coffee exported to roasters. How coffee is plucked, washed, and dried will influence the mouthfeel, aroma, and taste.
Quoted from coffeebean.com, it is also said that after harvesting the coffee cherries, the beans are extracted from the cherries. This process is more complicated than it sounds because coffee cherries have many layers: silver skin, parchment, pectin, pulp, and outer skin. Therefore, farmers need to remove these layers to obtain coffee beans. This procedure is called processing.
In the coffee industry, there are several coffee processing methods that are usually used by producers, the most familiar of which are natural or dry, honey or pulped natural, and the most popular among them are washed or wet process.
Well, why washed coffee processing is the popular one? What about the taste? Let’s dig deeper to know more about washed coffee processing!
What is Washed Coffee Processing
Before discussing what is washed coffee processing, what exactly will differentiate coffee processing?
Quoted from perfectdailygrind.com, it is said that between harvesting and storage/export, there are two main things that need to happen: the fruit needs to be removed and the beans need to be dried to an appropriate level. The main differences between how coffees are processed lies in the order this happens in.
Carlos Oliveros, Principal Investigator at Cenicafé, the research centre of Colombia’s national coffee association Café de Colombia through perfectdailygrind.com said that a washed coffee is a coffee which has had various fruit layers removed before drying begins. We remove the skin, remove the mucilage. and only allow the parchment and the silverskin to remain.
The majority of the coffee we consume is usually processed using the washed processing method. Of the three processing methods, washed is the most reliable technique and has a higher likelihood of producing successful flavor characteristics.
However, that does not mean that washed coffee processing who’s popular and is a reliable processing technique means that it is not unique and high quality, cause it is. Coffee from washed processing also has a unique taste and is one of the best sellers.
How Exactly the Process in Washed Coffee Processing
Quoted by blog.lakopi.id this method requires a lot of water and aims to remove the skin and flesh attached to the coffee beans. The skin of the coffee cherries will be separated using a de-pulper machine. Then, the remaining skin that is still attached will be cleaned again with water so that the coffee beans are cleaner. Using warm water will make this method easier.
While the beans are immersed in the water, the pulp (or mucilage) covering the beans are agitated by a de-pulping machine until it eventually falls off. What distinguishes it is in the process of cleaning the coffee cherries using water before drying. Initially, the coffee cherries will be selected by a soaking process.
This soaking process is a part of fermentation. where the coffee beans are submerged in water ranging for a few hours to even a couple of days. The amount of time is dependent on climate, the type of equipment used, and the personal preference of the producer. The coffee that floats when soaked will be discarded, while those that sink are considered ripe and ready to be processed to the next stage.
Quoted from sagebrushcoffee.com, once the fermentation is complete, the beans are rinsed and then dried outdoors on a raised bed or with a mechanical dryer. The drying technique used will decide how long this final step takes. The order of fermenting and then drying allows more control over the process, thus producing a more consistent coffee.
Washed Coffee Processing Steps
In every coffee processing, there must be several steps that must be applied. On washed coffee processing, there’s four steps you need to know:
After being harvested or picked, the coffee cherries will go through a sorting stage, where this stage is a process of removing any defective or unripe cherries. Quoted from coffeebean.com, first, the coffee cherries are compiled and put into floating water to sort out the ripe and unripe cherries. The ripe ones – good coffee – will sink to the bottom, while the unripe ones – bad coffee – will float to the top.
Carlos Oliveros, Principal Investigator at Cenicafé, the research centre of Colombia’s national coffee association Café de Colombia through perfectdailygrind.com said that higher-quality coffees are denser than water, in contrast, defective cherries have poorly formed seeds, creating air gaps. This means they float.
So, the cherries that float in the water normally tend to be defective. It could be because of damage by the coffee berry borer (a common coffee pest) or it could be something that happened on the farm that prevented the coffee from fully ripening. Many coffee producers and farmers suggest separating the two coffee beans – floating and sinking, if you want to process and sell them you have to separate them because of differences in quality.
The next step is to remove the pulp or the skin of the cherry. A machine called a depulper can be used to do this. The ripe cherries are thrown into a de-pulping machine, where the outer parts are removed and the seeds – or coffee beans – come out.
Next step is fermentation. As we know, coffee must go through a fermentation process in each processing method. Quoted from perfectdailygrind.com said that fermentation is key to understanding and controlling these processing methods. Coffee is a fruit and, like most fruits, it is full of nutrients, sugars, and other chemical compounds. In every coffee processing there will be a fermentation process.
Fermentation is a natural change that occurs when sugar and water combine – and coffee cherries are full of both. So, as soon as the coffee cherries have been picked (or sometimes before, depending on the humidity), the fermentation process will begin.
The coffee will usually ferment in a tank (traditionally) and takes 18 to 24 hours, depending on the temperature and coffee value. During this time, the microorganisms in the beans create the enzymes responsible for breaking down the mucilage.
On the other hand, some countries have slightly different fermentation methods. Pil reminds that, in Kenya, a process called double fermentation is common. This means the beans are soaked in water a second time, resulting in greater water usage but very clean coffee.
The final stage is the drying one. No matter how the coffee is processed, at some point, the coffee beans need to be dried. For washed coffee, drying is done after the cherries are peeled and mucus removed.
Coffee is dried in two main ways. First, through the traditional way, namely drying coffee beans in the sun. The second is to use a special machine for drying coffee. Smaller farms often dry the coffee under the sun while larger ones may use mechanical driers.
There are two main factors that contribute to how coffee dries: temperature and airflow. Over time, this reduces the moisture in the green beans. During the drying process, it is important to pay attention to the temperature limits for each type of processing method; Parchment coffee should not be dried at a temperature higher than 40 ° C, while natural coffee should not be dried above 45 ° C.
Apart from maintaining the temperature during the drying process, what must also be considered is the humidity level to prevent mold from developing in the coffee beans. The humidity level for drying will be between 40-50% and should be reduced to 11-12%.
When drying coffee using mechanical dryers, the coffee is usually dried in the sun to a certain extent. The use of a dryer is to complete the process with more precision and accuracy. When dried only in the sun, washed and semi-washed coffee will take less time to dry (6-9 days).
Coffee drying is also one of the longest processes in the post-harvest production stage and, as a result, is a major inhibiting point for processing coffee beans. Drying timelines vary depending on a number of factors, including weather conditions and processing methods.
There are some drawbacks to each of the drying methods, the risks of coffee drying in the sun including uncontrolled fermentation, animal contamination, improper manual drying, and bad weather conditions, all of which can have a big impact on coffee quality.
Animal contamination includes larger wild animals that cause physical damage to the seeds and animal waste (such as from birds) that fall between dry coffees. Finally, improper manual drying occurs when the coffee is not dispersed properly, resulting in exposure to uneven temperature and airflow.
Whereas there is drying using a mecanical dryer there are three main advantages over drying coffee in the sun: it eliminates uncontrolled environmental variables that can affect coffee quality, increases accuracy, and minimizes delays. One of them is the factor that is often worried about coffee farmers / producers, namely unpredictable weather.
How About the Flavor?
Quoted from sagebrushcoffee.com the way a washed coffee tastes has a lot to do with this method. The word “clean” is often used to describe the flavors of washed coffees. Unlike the natural and honey processes, where a lot of the flavor comes from the fruity sugars of the pulp left on the beans, most of the flavor found in washed coffees come from the bean itself.
From coffeebean.com also said that Java enthusiasts praise washed coffee for its purity. It allows you to taste all the vibrant notes and distinct flavors of the origin and variety. This clarity is mainly due to the removal of the cherry before drying.
In other words, as perfectdailygrind.com mentioned that with a washed coffee, you are tasting the coffee itself – the origin, the coffee variety, the terroir – and not the impact of the processing method. It means that washed processing is best suited to coffees with a great taste profile. Washed processing can result in clean acidity – that lively, fruity characteristic that so many specialty coffee lovers find delightful.
Although not as fruity as natural coffees, washed coffee beans almost always produce a cleaner cup with a lively acidity. In a Latin American coffee, a washed bean is going to show more of the caramel or nuttiness so prevalent in that region. Washed coffees are a delight to brew, and various brewing techniques will make a delicious cup.
Washed coffees are often consistent with the flavour. When natural and honey processed coffees is harder to predict the final cup profile (for this reason, they require strict quality control). This is because the fermentation continues within the coffee fruit during the drying phase, which can last for a long time. With washed coffees, all the fermentation happens at the beginning and so is easier to control.
One of the biggest criticisms of washed processing is its high water usage. Not only is this an issue in places with water shortages, but poor disposal of the wastewater can result in chemicals entering local waterways. This has led coffee associations and equipment manufacturers to invest in finding ways to achieve the effect of washed processing without the environmental cost.
The main challenge, for the coffee industry, is to ensure that washed processing is as clean for the environment as it is in the cup. But with new equipment and a growing awareness of the importance of this, it’s clear that washed processing today is not like it was ten years ago.
CV. Buah Berdikari is an active coffee trading and exporting company that is based in North Sumatera, Indonesia. Our domain of expertise lays on sourcing Arabica green beans from North Sumatera and Aceh origins. We will help you finding the perfect fits for your coffee needs.