Coffee Processing: A Complete Breakdown

Every type of coffee starts with a coffee bean.  Before coffee beans can be roasted, a lot of steps have to happen. It’s not as simple as you might think.  The coffee beans have to be harvested, processed and only then can they be roasted to make coffee. What is the processing of coffee?

Coffee processing involves removing the coffee beans from the cherries, and drying them out to get green coffee beans that are ready for roasting. Processing coffee cherries is one of the first steps to ensure that you have a delicious cup of coffee in the morning.

There are multiple ways to process coffee, which I will discuss in more detail. Despite there being many ways to process coffee, there are some ways which are most widely used. What are the most popular ways to process coffee?

Overall, there are three main ways and a few lesser-known ways to process coffee. These include wet-processing, dry-processing, and honey-processing, but they are all done to achieve the same result. Each is a method for removing the coffee beans from the cherries and drying them to prepare for roasting.

Each processing method has unique characteristics that affect the cost, quality, and flavor of the beans.  If you are trying to decide which coffee you like best, you need to start at the beginning — how it’s processed.  I will break down each of the processing methods below to help you understand what makes each method different.

What Is Wet Processed Coffee?

Wet processing is the most commonly used method of processing coffee. It is also called washed coffee because this process involves washing the outer layer of fruit and mucilage from the coffee beans before drying them. 

In general, wet-processed coffee is a method of processing coffee using machines to wash and remove the pulp from the cherries.  This process separates the beans from the cherries before drying them.  Because of its use of water, it is called wet-processed coffee.

Here’s a basic rundown of how wet processing works. The first step in any processing method is to harvest the cherries.  For wet-processed coffee, you need large ripe cherries. This is mainly because of the machines involved.  Smaller, unripe cherries get filtered out and will not make it through the entire process.

The cherries are hand-picked. Then poured into a large vat filled with water. The vat mechanically shakes the cherries and filters them through a screen that removes any unusable cherries. These cherries are run through a depulper that removes the outer covering of the cherries but leaves some mucilage on the bean. The beans are then soaked in another tank for 12-36 hours to break down any remaining mucilage. This results in a pure coffee bean that has no remaining fruit on it. The beans are then dried in the sun.

Because of its efficiency, farmers can mass-produce coffee using this processing method. Washing the beans removes any contaminants from the coffee, creating clean coffee beans. This method eliminates the potential for spoilage and allows farmers to produce consistent, high-quality coffee. Although it has its advantages, it costs more than other methods, and washing the beans strips the beans of many of their natural flavors.

What Is Dry Processed Coffee?

Dry processed coffee is produced without the use of water, or very little water  It is the oldest, and original method for processing coffee. It is often referred to as natural coffee because it doesn’t use modern equipment and it is a more natural method of processing coffee.  Countries with limited water supplies still use this process.  While coffee drinkers often prefer the clean taste of wet-processed coffee, this processing method ferments all the natural fruit flavors into the coffee beans.

As a general rule, dry-processed coffee is produced using natural methods. Harvested cherries are laid out on a concrete patio to dry in the sun. The cherries ferment over several weeks until all of the fruit is absorbed into the beans. They are then sorted and packaged.

What makes dry-processed coffee so different from washed coffee is the fermenting process. Unlike washed coffee, there are fewer steps and nature does most of the work.  Dry processed coffee requires a dry climate. This is why countries like Ethiopia and Kenya often produce more of this type of coffee.

Dry processed coffee is produced using just a few stages. The cherries are harvested from the coffee plant. They are then placed on a large concrete slab to dry in the sun. Workers rake through the cherries several times a day to remove moisture and keep them from rotting. They remain in the sun for several weeks until the cherry completely ferments, leaving just the bean.

With the modernization of coffee production, this process was taken over by wet processing n many areas. However, it’s beginning to grow in popularity for a couple of key reasons.  Wet processed coffee uses a lot of natural resources, and also dumps wastewater into the water supply of the countries where it is being produced.  As consumers push for more environmentally friendly methods for producing coffee, dry-processed coffee has grown in popularity.

In addition, because this coffee is not washed, the beans ferment the entire cherry flavors into the bean, creating coffee with a distinct, sweet, berry-like flavor.  For people that like more variety in their coffee, this coffee is both natural and flavorful.

What Is Honey Processed Coffee?

Honey processed coffee is the newest method for processing coffee. It uses a combination of the wet process and dry process to produce a natural, yet clean coffee.  Although the name honey processed might lead you to believe there is honey involved in this process, honey is not used in this process.

In short, honey processed coffee is a process that washes the cherries before drying but does not remove all of the fruit from the beans. The beans are partially covered with mucilage and dried in the sun.  It is called honey processed because the word mucilage translates to honey in Spanish.

Honey processing evolved as coffee producers started exploring ways to produce coffee using less water. Although the wet process is more efficient, it requires large amounts of water and produces a lot of wastewater.  It is more difficult to produce washed coffee in countries that have limited water resources. Because of this farmers started working on alternative methods for processing their coffee, and the result was honey-processed coffee.

This coffee process is the most complicated of the three major types of processing. This process starts with the same steps used in washed coffees. The beans are harvested, washed in a vat, and de-pulped. Instead of fermenting the de-pulped beans in water, the mucilage is left on the beans. This eliminates the need for the second round of washing.  Depending on which type of honey processing is used, anywhere from 20-100 percent of the mucilage will be left on the bean. The mucilage-covered beans are placed in the sun to dry. They are then processed in a similar manner as dry-processed coffee. They are raked throughout the day, but because the pulp has been removed they take far less time to dry.

As honey processed coffee’s popularity has taken off, farmers have created various methods for producing this coffee including white, yellow, red, and black honey processed coffee. The colors refer to the amount of mucilage left on the bean during processing.  What people like about this coffee, is that it is washed, cleaning the beans of any impurities, but also partially fermented. This allows farmers to produce a consistent coffee, but still gives the beans more of the natural fermented flavor that dry-processed coffees have.

Other (Less Popular) Methods of Processing Coffee

In order to give you a comprehensive breakdown of coffee processing, I’ve included a few lesser-known methods of coffee processing. While these methods are less popular, some of these techniques are really interesting and create fascinating, unique coffees that you might not have heard of.

Semi-washed Coffee

Semi-washed is a broad name for coffees that are processed using washed processing and dry processing. Honey processed coffee is the most well-known of the semi-washed coffee, but there are a couple of other semi-washed coffees. You might have heard the terms wet-hulled or pulp natural. These are two types of semi-washed coffees.

Wet hulled coffee

Wet hulled coffees are mainly found in Indonesia. This processing method is very similar to honey-processed coffee, with the exception of how it’s dried. Because the climate in Indonesia is not suitable for long periods of drying, coffee farmers process coffee a little differently. Basically, wet-hulled coffees are coffees that have been partially dried but then sold to market as is.  The farmers wash the beans, like a washed coffee. Some of the mucilage is removed, but instead of allowing them to dry in the sun till their moisture level reaches 10-12 percent, they are removed from the concrete when their moisture level reaches 50% or less. They are then placed in bags and sold at the market. The purchaser will take the wet-hulled beans and place them on a patio to continue drying.

Pulp Natural Coffee

Honey-processed coffee and pulp natural coffee are quite similar, in that both remove most of the pulp from the cherry before drying the beans. Understanding the difference between the two can be confusing. In both methods, they don’t soak in a fermentation tank before drying. Some people consider pulp natural coffee a form of honey processing. The main distinction between the two is the amount of mucilage left on the bean and where they originate Pulp naturals leave far less mucilage on the bean and are typically produced in Brazil.

Double Washed Coffee

Double washed coffee is pretty similar to washed coffee, except as the name implies, they are washed a second time.  Like washed coffees, they are placed in a vat, de-pulped, and soak in a tank to ferment. Instead of drying the beans at this stage, they are channeled into a second tank and soaked for an additional 48 hours.  After the second wash, they are placed on concrete patios to dry.

Carbonic Maceration

Carbonic maceration is a method used to produce wine. This coffee processing method takes the fermenting techniques used in making wine but uses them to process coffee. It is one of the most interesting ways to process coffee. It originated in France and uses most of the techniques used with washed coffee, but instead, the whole cherries are placed in a sealed tank to ferment. Carbon dioxide is injected into the tank to aid in the fermentation process. The temperature in the tank is kept much colder than with washed coffee, and they are left in the tank for a longer period of time.  Once the fermentation process is completed, they are removed and dried in the sun.

Anaerobic Fermentation Process

The anaerobic fermentation process is nearly identical to carbonic maceration, the main difference is the cherries are de-pulped before being sealed in a tank. This length of the fermentation process can enhance the flavor of the coffee in the same way that fermentation length and time affect the taste of wine.

Monsooned Processed Coffee

Monsooned Processed coffee is an unusual way to process coffee that was discovered by accident. This process originates in India and is called monsoon processed coffee because the monsoon season is what led to its inadvertent development.  In India, they have rainy seasons that make it nearly impossible to store coffee beans without them getting wet. What would happen is the beans would get soaked during shipping, and swell. When they dried out, they discovered they people actually liked the way the coffee tasted.  This coffee has a milder taste than traditional coffee. Over time this method was perfected, and farmers in India now process this type of coffee during monsoon season intentionally.  This method alters the taste and acidity of the coffee, and many people have come to love this specialty coffee.

Tim S.

Tim loves roasting, brewing, and experimenting with coffee. After years of perfecting this craft, working as a barista, and owning a small coffee service in college, he has decided to share his knowledge with the world.

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