Coffee bean processing methods | Passion for Coffee

Now I want to show you what complex processes this plant goes through after harvesting, which then largely determines the work of the roasters and ultimately the taste of our coffee.

After harvesting the coffee cherries, processing should begin immediately in order that the ripe fruit gives the best quality coffee beans. Different coffee bean processing methods have developed in different parts of the world, depending on local conditions and possibilities.

In many countries, water is a scarce and expensive treasure, there are places where human labor is cheap, there are places where the whole process is mechanized. Each processing method has its advantages and disadvantages, and its effect on the taste of the coffee beans. There are farms where the crop is processed locally, there are several farms where there is a common mill, and there are also large purchasing and processing plants.

Now let’s see the methods and their names in order! The main difference is that the freshly picked fruit is left to dry whole, some fruit flesh is immediately removed from the seed, or the flesh of the ripe cherries is immediately minced and the coffee beans themselves dried.

THE NATURAL / DRY PROCESS

Natural procedure take us back to the roots of processing methods that come from Ethiopia. The oldest and cheapest way to process coffee. There are countries where there isn’t water so no other method is conceivable.

It is usually the preferred processing method for lower quality coffees sold in local markets, but it is also used for high quality coffees, but in this case it takes a lot of extra work and attention to control the process to make the right quality and flavour of coffee beans.

Although this requires a smaller investment, in certain climatic conditions, such as a lot of sunshine and rainfall, it is only possible to apply it.

First they wash the freshly picked coffee cherries to remove impurities. In this case, the fruit flesh is left on the coffee beans. The cherries are spread out on the floor or racks and dry in the sun for 2-3 weeks. They are often rotated otherwise the beans start to rot and mold. After reaching the required moisture content (max. 12%),the beans are peeled off.

These coffee beans eventually turn brown and mottled after peeling.

Its advantage that it can add a lot of extra fruity flavour to coffee beans as the flesh dries together with the coffee beans, i.e. the seeds.

However, the disadvantage is that many unpleasant flavours can also appear using this method that are not good for coffee. This is due to the fact that the drying grains have to be rotated very carefully and with a relatively large amount of work in order not to start the process of rot or mold.

It’s not easy to ensure a particular quality with this method because difficult to influence the factors and easily gives more negative results in terms of taste than positive ones.

At the same time, there is a large camp for dry coffee, who say that the dry process can provide a similar quality, and this method is especially suitable for extracting a variety of flavours.

It is a common method in Brazil, Ethiopia, Indonesia and Peru.

Taste world: Its full-bodied, strong taste is characterized by strong fruitiness, because the beans dry together with the fruit flesh.

And last but not least, the dry process is the most environment friendly method.

THE WASHED / WET PROCESS

In the other main way to processing coffee the professionals focus specifically on the flavours, they try to achieve the flavours inside and ignore the possibilities inherent in the outer skin of the coffee bean.

Immediately after harvesting the coffee beans are washed, the all flesh is removed mechanically with a pulper and then they put the seeds into water ranks where begin to ferment due to the pectic layer on them.

Fermentation lasts as long as this pectic, sticky layer is on the seeds, this can take a minimum of 12 hours, a maximum of 5-6 days. They are then washed again, dried and the peel left on just at the end is peeled off.

While the richness of the cherries surrounding the beans plays an important role in the dry and honey processes, in the washed process the taste depends almost 100% on whether the coffee plant has absorbed sufficient natural sugar and minerals during its growth cycle.

Therefore in this process, the final result is greatly influenced by the type of plant, the soil chosen, the weather, the maturity of the berry, the process of fermentation, washing and drying.

The processing of washed coffee also proves that the work of growers plays a big role in creating a coffee plant with good properties. In addition to their precise work, the taste characteristics are largely determined by the farmland, and thus also by the country of origin and its climate.

It follows that washed coffee is able to best highlight the original characteristics of the coffee bean, which is why in the world of specialty we often encounter this procedure and coffee fanatics often prefer this method as well.

Due to the fermentation, we can make coffee with an acidic taste, but due to the process, this method is the best way to highlight the varietal characteristics.

THE HONEY MIEL PROCESS

It’s similar like semi washed, halfway between washed and dry.

If we consume a well-made, honey-processed coffee, it can be as sweet as if honey or a spoonful of sugar added into our coffee, but the method didn’t get its name from this, but from the sticky surface of the coffee that is experienced during processing.

It requires careful drying and handling to give the same sure quality as the washed process.

The honey coffee process is the hardest and most demanding coffee processing method.

The processor spreads the coffee beans thinly and than spreads it out on special drying beds without any washing to leave part of the pulp and turns them after every one hour for 10-15 days to gain the needed stability.

And the result is usually a coffee with fine elegant attributes associated with the high-end washed coffee coupled up with substantial fruit and body sweetness of the natural coffee. .

The processors base the grouping on the percentage of flesh they leave on the coffee bean after pulping and the drying process.

In this process, although the flesh is removed, the pectin layer is left on the beans. The sweetness of coffee depends on the amount of sticky pectin layer, so it is a very delicate process to know exactly how much is left on it, as the chemical process that takes place gives the end result. The more of this layer is left on it, the more sweet coffee we can usually get.

Together with the pectin left on it, the beans are exposed to dry and this is when the fermentation process takes place. Depending on how long the fermentation lasts the seeds change colour, based on this we now distinguish between yellow, red, gold, black, and white honey types.

Its benefit less water use therefore more environmentally conscious, cheaper than the washed and precisely controllable procedure.

In Costa Rica, this method is the most common, but it is also becoming increasingly popular in the Central American region.

It is characterized by a fruity taste but not as much as dry process coffees and less acidic than a washed coffee. It is characterized by an intense sweet taste and a complex sip feeling, but at the same time less full-bodied than what we can experience with the dry process.

Other coffee bean processing methods

THE SEMI WASHED/ WET HULLED

Aims to provide high quality using less water. Most of the fruit flesh is removed before drying. It is somewhere halfway between the natural and the washed process. Less risk, relatively high quality end result.

After harvest, they are washed, the meat and shell are removed, and the fermentation process is skipped and the pectic layer is also removed, dried and peeled. This uses much less water than washed. It is therefore characterized by lower acidity and a clearer taste.

Ripe cherries are filled into containers filled with water and washed. Unripe grains float to the top of the water, thereby also sorting out.

Peeling machines are used to remove the ripe fruit flesh from the seed. It is important that the peeler removes the flesh of the fruit, but the so-called “mucus layer” remains on the seed. So far, the method is the same as the washed process.

The beans thus prepared are spread on drying racks and they are often rotated to dry evenly and slowly in the sun. There was little left on the seeds.

After the grains have dried, the beans covered with parchment-like shells are speckled with reddish and brown spots.

Its advantage in addition to minimizing the chance of adverse effects, show sweeter, more complex flavors additionally more environmentally conscious because they are using less water and cheaper than the wash process.

The method is most common in Brazil and Indonesia.

Fully Washed

In this case, even the coffee of several coffee growers is processed at the same time. They do it in huge water pool colonies where they first pick good grains in the water and then remove the meat and outer shell but leave the pectic layer on it.

This is how they are dried for approx. for 12 hours, then put back into a water basin for another 12 hours, then washed and soaked for another 10 hours.

Processing is then completed by a 1-2 month drying process and peeling.

It is most common in Rwanda and Burundi. We get a full-bodied yet light coffee with aromas typical of the area.

FROM DRYING TO SHIPPING

After washing, processing and drying, the coffee beans still have the parchment skin on it (except for wet-hulled coffee). The moisture content of the grains is 11-12%. This is followed by the following processes:

The coffee is rested in a “dry mill” for 30-60 days. Maturing the taste of coffee is important. If you miss this rest, it will taste very green.

During peeling, the outer parchment shell, which has so far protected the eyes, is removed.

Raw coffee beans are placed on a conveyor belt and selected into different quality classes according to their density, size and colour. There are places where there are optical sensors, there are places where women sort their eyes according to their colour. Size selection is performed with perforated steel plate sieves.

They put quality coffee in 60 or 69 kg jute or lined jute bags, the lower quality coffee is covered in lined containers.

And one of the reasons of why specialty coffee 🙂

Specialty coffees are professionally packaged, often in a lined bag or vacuum pack so that the quality cannot be affected by the weather during transport!