A Guide to Green Coffee processing

The need for coffee dealers and roasters to offer a wide variety of coffees has led to the introduction of a variety of coffee processing techniques. As coffee consumers become more enlightened, the demand for processed coffees grows at a very high rate.

In the very competitive world of coffee, it is the roaster or importer with the widest variety of coffees that reaps the rewards. Many coffee importers are investing in washing stations and coffee cooperatives so as to enable and empower them to produce well-processed coffees. 

When it comes to green coffee processing, there are two distinct methods. These are the wet and dry processing of coffee. With wet processing, water is used at some point of the process while no water is used at all in dry processing. Dry processing is also referred to as natural processing.

Coffee dealers and roasters have a choice to make depending on the offering they wish to have. Each processing method has its strengths and drawbacks, but if properly done, the processing tends to elevate the quality and by extension, the prices that the coffees can fetch.

More investments are being directed to the experimental processes where roasters are investing in equipment and training to producers to have different coffee offerings. This is in part due to corporate social responsibility and part sustainability efforts.

Alternately processed coffees fetch premium prices that encourage the producers to increase production and maintain quality.

Types of coffee processing.

Dry Coffee Processing. (Natural Processing)

This is the oldest method of processing coffee and is still used in many countries where water resources are limited. The freshly picked cherries are simply spread out on huge surfaces to dry in the sun. They are usually turned over severally to ensure uniform drying and avoid rotting.

After the drying process, the naturals are taken for hulling to obtain the green beans. This method is also referred to as Natural Processing. According to the Polish Journal of Natural Science, Natural coffees that have been properly dry-processed can be a quality product with their own market. Natural coffees are a basic ingredient of espresso blends and, as such, they enjoy a growing demand, especially for high-quality products.

For Coffee traders who value the highest quality with the naturals, they can ensure that coffee cherries are first passed through a floatation chamber to do sorting before drying. This will ensure uniform quality of the resulting coffee. For roasters who enjoy coffees with exotic flavors and wild notes, naturals provide this and more. The naturals tend to be fruity, winey, and with well-developed sweetness. This appeals to specialty coffee consumers and casual consumers as well. The naturals also have a distinct fermented flavor and can also be alcohol-like. Baristas like using these naturals to showcase the potential of coffees.

Washed Processing.

Perhaps the most common and most popular coffee processing, this method involves the pulping of the cherries to obtain parchment. This parchment is then transported with water to fermentation tanks where the thick sugary substance is broken down. This sugary substance (mucilage) is then completely removed by washing the parchment in washing channels where clean water is used.

Most coffee traders, roasters and consumers like the washed coffees because they have clean cups, bright acidity, and are full of flavor. Most coffee from East Africa undergoes this process and no wonder this coffee is hugely popular.

After the washing is done, sometimes coffee is soaked overnight in soaking tanks full of clean water whereby any remaining mucilage or any off-flavors are washed off. Coffee consumers love washed coffees due to their unmatched complexity, bright acidity, and balanced bodies.

When done properly, this method reduces the risk of coffee defects that arise due to the processing techniques. Roasters who invest in washed coffees always praise them due to the high, constant demand that they command.

Honey Processing. (Pulped Natural Processing.)

This is a very popular processing method, especially in Latin America. It produces some very balanced cups full of flavor with fruity notes. This raises the acceptability index with the prices fetched by the honey-processed coffees being some of the highest in the coffee sector.

Coffee cherries are harvested when red ripe, they are then pulped to remove the outer skin. Instead of washing or fermenting the parchment, the coffee is taken directly to the patios or the drying tables.

Drying is done very carefully to ensure it is not done too hastily or too slowly. The key is to ensure the mucilage is absorbed by the bean. These sugars eventually give the honey-processed coffees very desirable notes and flavor.

This method is called honey because of the color of the processed bean. The color resembles honey while being sticky because of the mucilage. 

Some mucilage is still lost due to partial fermentation. Depending on the amount lost, honey processing has several references. For instance, Black Honey refers to coffee with little or no mucilage lost, Red Honey is where only less than half is lost, Yellow Honey has 50 – 75% mucilage lost while White Honey has most of the mucilage lost.

In countries such as Costa Rica, more roasters and coffee importers are investing in producer associations to control the whole processing. This ensures the honey processing is done the right way so as not to compromise on quality and flavors. This investment is allowing the roasters to have a wider stock-lot of experimental processing coffees.

Carbonic maceration.

This is a relatively new method of processing coffee. Maceration refers to fermentation in a carbon dioxide-rich environment. In the case of coffee, cherries are placed in airtight containers such as steel barrels, and carbon dioxide is introduced.

Fermentation occurs within the cherry. This coffee produces high-quality cups with fruity notes and winey flavors. This is a great addition to any coffee roaster because the possibilities are endless.

More roasters are getting involved in projects at the origins involving various iterations of the carbonic maceration. The aim is to get involved more in the process to ensure success and set themselves apart from their competition.

Anaerobic fermentation.

Unlike carbonic maceration, anaerobic fermentation involves fermenting coffee in an environment devoid of oxygen. This can be done in an airtight fermentation tank where carbon dioxide can be manually introduced or the co2 might come from the fermentation where it is a by-product.

This gives producers an extended period of fermenting the coffee. The resulting coffee is a favorite of specialty coffee consumers due to the intense flavors and the formation of exotic notes such as wild fruits.

This method has attracted the attention of many coffee roasters and importers who have been encouraged by the potential of the coffee to have very high-scoring cups.

Coffee quality is greatly influenced by the processing technique employed. If properly done, the flavors are greatly enhanced and this creates a niche market for these types of coffees. A coffee trader with a diversified stock lot will always have a huge advantage in the market.

Investing in experimental processing is a great way for importers, traders, and roasters to make their mark in the very competitive coffee sector. Processed coffees have huge potential and the prices they fetch for the producers are enough to sustain them.

Creating niche markets with these processing techniques will enable the coffee traders to set themselves apart and ensure a sustained supply of high-quality coffees.

Also, learn more about Buyer’s guide to Green Coffee Bean Species