Coffee processing is one of the longest part from coffee production. There are many stages that have to be gone through before we can enjoy our daily cup of coffee. Starting from coffee cherry harvesting, processing, drying, roasting, and others before becoming the cup of coffee that we consume every day.
Of course, all the stage of coffee processing need a good attention and a lot of things to be considered. Coffee beans are sensitive commodity and can quickly become contaminated if not processed properly. As much as we need coffee in the morning before start our day, coffee beans need to be processed carefully in order to get a good quality of coffee beans. And yes, a great cup of coffee.
If we didn’t pay enough attention to all the process, it will make the characteristic and as what you imagine -the flavour of coffee isn’t good. The quality of green beans coffee is important, so that we can have a good cup for our coffee and coffee processing is one that influences it.
Before we went into something chemical like charectiristic and flavour, let’s take a look the things about coffee processing and things that affect coffee beans (the characteristics and the quality and flavour). Some of you maybe familiar with that, or most of you didn’t know it yet. Let’s take a look together!
Things About Coffee Processing You Need to Know
In general, the post-harvest coffee process is divided into 2: the dry method and the wet method. Dry method is including natural process while wet method includes washed process. Processing part are consist of two important things: fermentation and coffee processing method.
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. Quoted from perfectdailygrind.com said that the main differences between how coffees are processed can be distinguished based on the sequence of acitivities.
From now, let’s dig more about types of coffee processing.
As the name implies, this processing method does not involve machines and water, is natural and is the oldest processing method. Coffee cherries that have gone through the sorting process according to their quality will go through the process of drying or drying in direct sunlight. Some coffee producers sometimes dry them on a plastic mat or a special drying table with an airflow at the bottom.
In a natural process, cherry coffee that is dried by drying it directly under the sun is not peeled first, but leaves the cherry coffee with the skin and flesh of the fruit. During this drying process, the coffee must be continuously checked and alternated to avoid rotting and dry evenly.
This process will make the coffee fruit naturally ferment and peel off by itself. The natural process method will produce a variety of fruit flavors, not just bitter or sour tastes. Published on perfectdailygrind.com also said that when this process done well, it should be highlight sweetness and result in a round body, although these coffees are unlikely to have more than a medium level of acidity.
Some of you maybe know this process as wet coffee processing, well washed process also means wet process in coffee. Carlos Oliveros, Principal Investigator at Cenicafé, the research centre of Colombia’s national coffee association Café de Colombia via perfectdailygrind.com said that “A washed coffee is a coffee which has had various fruit layers removed before drying begins. We have removed the skin, we have removed the mucilage.” Only the parchment and the silverskin remain.
From blog.lakopi.id mention that wet method requires a lot of water and aims to remove the skin and flesh attached to the coffee beans. What distinguishes it is in the process of cleaning the coffee cherries using water before drying. Initially, the coffee cherries will be selected by immersion process. Coffee that floats when it is soaked will be discarded, while those that sink are considered ripe and ready to be processed to the next stage.
The skin of the coffee cherries will be separated using a depulper machine. Then, the remaining skin that is still attached will be cleaned again with water so that the coffee beans are cleaner. The clean, peeled coffee will be dried in direct sunlight. This method will produce coffee beans that are light and soft, clean, light, tend to be fruity, and have a high acidity level.
To get to know the types of post-harvest processes in coffee, the last one is to use the hybrid process method. This method is a combination of a normal process and a washed process. There are 3 hybrid process techniques based on the different methods used that maybe familiar with you.
Pulped Natural Process
This method is often used by coffee farmers in Brazil. The coffee cherries will be peeled using a depulper machine to separate the coffee beans from the skin. Then dried in direct sunlight. During the drying process, the remaining pulp will be peeled off. Usually, the remaining pulp that is still stuck during the drying process will give the coffee a sweetness sensation.
El Salvador and Costa Rica are countries that often use the honey process to separate coffee beans. The processing principle is almost the same as the natural pulped process. However, the honey process requires less water than the pulped natural process. The coffee cherries will be peeled using a depulper machine to determine how much pulp is left to adhere to the coffee beans before they are dried in the sun. This uniqueness is known as the honey process because it produces mucus or mucilage that sticks to the coffee beans.
Semi-washed is a coffee processing method commonly used in Indonesia, particularly Sumatra and Sulawesi. This method is also known as wet hulling. This postharvest process does not use too much water. The plucked coffee cherries will be peeled using a depulper machine to separate the coffee beans from the coffee cherries leaving behind mucus. Furthermore, the coffee beans and mucus will be soaked and dried in the sun.
This first drying takes a few days for the parchment skin to open. When the parchment skin is open, the coffee beans will dry faster. After that, the stripping will be done using a huller machine and then again in the sun until the humidity of the coffee ranges from 11-12%.
How Coffee Processing Affect the Flavour
Reported by perfectdailygrind.com the taste and aroma of coffee is developed during the roasting process. The aroma of coffee is produced from aromatic volatile compounds that are produced by chemical transformations that naturally occur in green coffee beans.
Then what is the relationship with the coffee processing process? The choice of processing method for coffee will in fact affect how much of each of the chemical components present in the coffee beans will come out when the beans are roasted, and therefore have an effect on the resulting flavor.
Then how coffee processing affect the characteristic and flavour?
The coffee cherries are surrounded by a layer of flesh called pulp that is around the coffee beans. The pulp in this cherry coffee contains a lot of sugar. So, what is the connection with the coffee processing process? Coffee processing simply can be described as a method to remove the flesh and skin from the coffee cherry so that only the coffee beans remain.Some of the coffee processing processes that we are familiar with like we mentioned before, natural, washed and the honey process.
In the natural process the coffee beans are completely dried in their natural form with the skin and pulp intact.
For the washed process, which is to remove all remaining mucus / pulp, both skin and pulp before drying the coffee. Meanwhile, the honey process / pulped natural processing is a process between the two – natural process and washed process. In this process the skin is removed before the coffee beans are dried, but almost all of the pulp remains on the coffee beans.
These different processing methods can make a difference to the taste of coffee due to the sugar in the pulp / pulp left behind on the coffee beans. As we mentioned before that there is two things affect coffee the most, coffee processing and fermentation. Let’s get deeper into this!
Fermentation in Coffee Processing
Report 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.
What is fermentation process in coffee processing?
Fermentation in food and drink is nothing new. Fermentation in food and beverages has become one of the ways to create new flavors and also provide other benefits from what the fermentation process produces. But for coffee?
Well, published by majalah.ottencoffee.co.id through Lakopi Indonesia said that fermentation is simply a process that produces a chemical reaction involving other microorganisms that help the process of decomposing something (in this case coffee) to produce something different. Microorganisms in this fermentation process help the development of coffee by releasing many substances, enzymes, maybe sugars and more.
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. In general, there is two types of fermentation aerobic and anaerobic.
- Aerobic: This method is done when oxygen is available. This type of fermentation technique is simple: just leave the freshly picked coffee cherries in the tank or container and let the microorganisms work. Monitor time and temperature to help make it easier to control and analyze.
- Anaerobic: In this case, the coffee cherries are placed in a tank (before or after pulping) and covered with water. That will allow different microorganisms to work.
How fermentation affect characteristic and flavour?
Natural coffee is sweeter than washed coffee in large part due to the fermentation of sugar in the pulp. Coffee from washed processes and natural coffee – both undergo fermentation, but the ingredients used by enzymes in washed coffee are much less because the pulp has been removed.
During fermentation, microbes modify the proteins, carbohydrates and chlorogenic acid in coffee beans. More precursors / formers of aromatic compounds are made in natural coffee. The result is not just a sweet taste, but fruity, floral, and caramel notes in the final cup.
In contrast to natural coffee from natural processes, washed coffee has a cleaner taste and features a more individual aroma than a particular / origin coffee. For honey-treated coffees whose processing includes removing the skin of the cherries allowing better fermentation of the mucus around the coffee beans. This results in a more pronounced sweetness in honey-treated coffees than natural coffees, with more buttery aromas and nut notes.
Now you know where the sweetness and fruity taste came from in your coffee, right? To know characteristic and coffee flavour notes is one of the way to enjoy our cup. Beside how you brew it, which method you use to brewing your cup of coffee, or which origin you grind, as long as it’s good quality coffee, you will enjoy it!
That’s why a good quality coffee beans are important. And coffee processing need to be success in order to make it a “good quality one”.
The very long process of coffee processing before we can enjoy it proves the need for dedication and care in maintaining the quality of the coffee beans that are there before we can consume it. The quality of good coffee will certainly be balanced to the taste offered.
Don’t forget to enjoy your cup of coffee today!