Processing the beans
Processing ("processing" in English) is typically something that appears on your bag of coffee, but does it matter to the taste?
There are many factors that have an influence on how the coffee tastes (e.g. grinding the coffee and roasting the coffee ), but one of the factors that almost always appears in a bag of coffee is processing . Although processing the coffee is by no means simple, there is a reasonable understanding of the influence it has on the taste of coffee. So in the following post, we take a closer look at what exactly processing means for coffee .
To understand the processing of coffee, it is important to understand that coffee is a fruit, and it is not possible to understand what effect processing has on the coffee, if you do not understand the structure of the fruit.
The structure of the coffee fruit
Coffee is more like a berry than a fruit, but despite that, is classified as a fruit - for that reason we use the term 'coffee fruit'.
The outside of the fruit, like so many other fruits, has a skin that protects the inside, an inside that consists of pulp. Inside the pulp there is a protective membrane, and behind the membrane, there is another thin layer. This layer is where the seed is firmly rooted, which is the part of the coffee fruit we call a "coffee bean", which after processing, roasting and grinding, ends up as your morning cup of coffee.
Apart from the purely logistical (such as transport and storage), there are two primary things that must happen before we end up with a coffee bean that is ready for roasting: the coffee must be dried and all the layers must be removed down to the last layer. The combination of the two things of basically what is called processing, and different processings are just different methods of drying and cleaning the outermost layers.
Washed processing
Taste: More acidity, less body
A very common form of processing is called "washed". With a washed processing, the skin and pulp from the coffee fruit are removed before the coffee is dried. This can be achieved in a few different ways. Often the coffee fruit is fermented either under water or in some form of fermentation apparatus. Fermentation loosens the pulp as well as the skin, making it easier to remove from the coffee beans. It can take place in many ways, e.g. using automated and mechanical processes, or by manual handwork.
After the skin and pulp have been removed, the washed coffee beans, together with the innermost layer, are dried. After drying, the inner layer is removed, leaving the raw coffee beans ready to be roasted.
Washed coffee tends to have a more acidic taste ( read more about acidity in coffee here ) and less body, compared to other types of processing. So if you drink a cup of coffee that is very fresh and mild, it is probably a washed coffee.
Natural processing
Taste: Less acidity, more fullness, more fruitiness and more sweetness
Natural processing got its name because through the processing, as far as possible, you try to copy the process that would happen if the coffee fruit had naturally fallen from the tree. The entire fruit, including skin, pulp and inner layers, is dried together, and it is not until after drying that the skin, flesh and inner layers are removed from the raw coffee beans. This type of processing results in less acidity in the coffee and more fullness in the taste, and in many cases, more sweet and fruity flavors. If you have ever tasted an Ethiopian coffee that tasted a little like blueberries, then the coffee has probably gone through natural processing.
Different fruity flavors are not the only thing that can come from natural processing. Many types of Brazilian coffee, which taste of chocolate and nuts, are the starting point for many espresso blends - and this kind of coffee will almost never taste fruity, regardless of how they are processed. So a natural processing produces fullness in the coffee and gives a stronger sweetness.
Honey process
Taste: Mix between washed and natural processing
The honey process is almost a middle ground between natural and washed processing. The skin and some of the pulp are removed, but some of the pulp is left on the inner layer of the coffee fruit during drying. The process is relatively new and invented in Brazil, but has since found its way to countries such as Costa Rica. It is not a process we see much of in Denmark, as it is not that widespread yet.
Giling Basah or "wet holed"
Taste: Earthy
In the "wet hulling" type, the skin and most or all of the pulp is removed before drying, but the coffee dries to only about 50% moisture before the coffee beans are removed from the inner layer. The coffee beans are then fully dried.
Despite a relatively small difference in the process, there is still a big difference in the taste, which can give the coffee a more earthy taste.
Drying
Even during drying, there can be many different processes involved, which can also have an impact on the taste of the coffee. Drying can be done purely mechanically in large drums, which is more reminiscent of large coffee roasters, which use lower temperatures. In the past, this type of drying has generally not been particularly recognized, mostly because too high temperatures have often been used. As this drying process has been improved and optimized, it has been possible to achieve a more consistent drying, which is why it has become more and more recognized.
Another method is drying in the sun, which also has many variations, from drying directly on concrete or directly on the street with a substrate, to what is most reminiscent of drying beds for beans with hot air circulating underneath.
What the future holds
Hundreds, perhaps thousands, of different ways to wash coffee exist, with several methods being invented and experimented with right now. Farmers try to control specific types of yeast in fermentation to produce different results, instead of letting the natural yeast do its job. Others introduce acids such as citric acid into the fermentation process to produce different flavors. Many farmers are constantly experimenting, which one must also argue has a certain risk and is not without costs. It also means that the same process we see today is not necessarily going to change overnight, but instead sees incremental changes.
With all the different factors and variables, we can roughly establish the following guidelines in relation to processing and taste: If you like clear and fruity flavors, look at washed coffee. If you like the coffee to have a good body with great taste, try natural processing. If earthy flavors are more your cup of coffee, try the 'wet-holed' processing.