Alchemy of Brazilian Coffee: Processing Methods (Part II)

The KALVE team experienced authentic farm life in Brazil, as Raquel Ribeiro Aguiar, the owner of the "Cerrado Grande" farm, warmly welcomed us to her cozy farmhouse, surrounded by 180 hectares of coffee fields right next to the processing station.

In Brazil, the most commonly used processing methods are natural (dry) processing and semi-washed (pulp-natural) processing. These methods are also used in "Sancoffee" coffee farms, which KALVE team visited in July. In this diary, we will delve into coffee processing methods and the techniques used in Brazil.

Climate, processing and coffee farms

Once coffee cherries are harvested from trees, they are brought for processing. In smaller farms, processing can occur on-site, where the farming families also reside. Larger farms are equipped with processing stations that can vary in size and equipment. These large farms can also function as family businesses, with residences, processing stations, and other structures within the farm's premises. For example, at the "Sao Paulo" coffee farm, the largest in the "Sancoffee'' cooperative (encompassing 2000 hectares of land, with 800 hectares of coffee land), activities include coffee cultivation, livestock farming, and sugarcane cultivation. There, a whole village has emerged, featuring a community center with a church and assembly hall, along with cottages and separate family homes where people work and live on the farm.

The choice of processing methods is primarily influenced by geographic location, local climate, and the ability to invest in processing stations. The Campo de Vertentes region provides perfect climatic conditions for natural processing. It experiences pronounced and extended dry periods in the winter season and moderate warmth, which is ideal for prolonged coffee drying.

 

July is usually the coldest month in the Minas Gerais region, with warm days (25-27°C) and cool nights (5-15°C), accompanied by sunny weather and minimal rainfall. Rainfall can be troublesome for farmers, as coffee drying happens under the open sky, and excessive moisture or rain can drastically impact coffee quality. Farmers rely on favorable climate conditions, as consistent temperature fluctuations are beneficial for the development of coffee flavor. Coffee trees and cherries undergoing processing are sensitive to rapid and extreme temperature swings.

For instance, in July and August 2021, Brazil experienced frost, leading to near-catastrophic consequences. It disrupted the coffee drying process and froze coffee trees and unharvested cherries. This significantly affected coffee prices not only in Brazil but in all coffee-growing regions. Coffee prices are linked to the stock market, which, in turn, is closely tied to Brazilian coffee prices.

What is Coffee Processing?

Coffee processing refers to a series of steps that shape the flavor of coffee and prepares it for storage, transportation, and roasting. The fundamental aspects of coffee processing include drying the coffee beans to around 10-12% moisture content and sorting them. Additionally, two consecutive yet equally crucial processes are fermentation and the separation of coffee beans from the cherry's pulp (the fleshy, juicy part rich in natural sugars).

The main distinction between processing methods lies in whether the coffee beans are separated from the cherry's pulp before or after the drying process. In the natural method, drying occurs first, followed by pulp  separation. This allows the coffee to absorb the sugars and other compounds from the pulp. On the other hand, in the washed method, the cherry's pulp is fully removed before drying. This requires the coffee beans to rely on all nutrients and chemical compounds they've absorbed during the growing process.

Increasingly popular in Brazil is a cross between the natural and washed methods, also known as the honey method, but referred to in Brazil as the semi-dried processing method. In this approach, the cherry pulp  is only partially removed before the drying process.

 

Semi-Dried (Honey) Processing

At the Campo Alegre farm, we visited a processing station featuring semi-dried coffee processing equipment (Wet-Mill). This structure houses various machinery, including water mills equipped with conveyor belts, a cherry separator machine, a rotating tank for separating defective cherries, as well as pumps and tanks.

This type of processing station helps separate ripe and quality cherries from defective ones. The water conveyor belt aids in this process by floating coffee beans, causing the ripe ones to sink while defective and unripe cherries float on the water's surface. The next step involves separating the coffee beans from the cherry skin. This is achieved using a depulper machine, which essentially removes the skin, leaving the soft and juicy fruit. The coffee is then spread and leveled on drying balconies.

 

The semi-dried processing method is popular due to its significantly shortened drying time, making the processing more efficient and ensuring consistency in coffee flavor and quality. This method imparts unique flavor nuances to the coffee, characterized by vibrant and pure notes, complementary acidity, and expressive natural sweetness. It often features a pleasant and complex texture with fruity, citrusy, and floral flavor notes. High sweetness levels are characteristic, as the coffee beans have been in contact with the cherry pulp, absorbing its sugars and other compounds.

Fermentation

Specialty coffee farmers are increasingly experimenting with the processing process, subjecting coffee to controlled fermentation for desired outcomes. At the "Samambaia" farm, we encountered coffee cherries placed in sealed water tanks. This creates controlled conditions that initiate fermentation, resulting in esters developing during the process. These esters create more complex and high-quality taste and aroma nuances in the coffee.

Similarly, Daniela, the manager of "Samambaia," along with her team, experiments with various additional ferments and additives during the fermentation process. For instance, adding extra yeast, sugar, and salt to coffee cherries influences the coffee's development, resulting in new and intricate compounds that yield a more complex and interesting taste. While salt is not a typical coffee additive, in small amounts, it can accentuate flavor nuances. We cannot yet reveal how this type of fermentation affects the coffee's taste, as we're still awaiting sample shipments from "Sancoffee." We will certainly share more about these flavor nuances once we have more information.

 

At "Cerrado Grande" and "Fagundes Community," we observed pile fermentation, where coffee cherries are stacked and covered. The temperature inside the pile gradually rises, creating favorable conditions for fermentation and producing more complex compounds, resulting in higher-quality taste. This serves as a great example that improving and enhancing coffee flavor doesn't necessarily require expensive fermentation equipment or substantial investments. Pile fermentation doesn't demand additional equipment, only control and supervision.

Increasingly, coffee farms around the world are experimenting with extreme fermentation methods, such as fermenting coffee for up to 200 hours or adding flavor-influencing and altering ferments (pineapple skin, lactic acid, lemon zest, alcohol). KALVE idea and belief are that the coffee bean is perfect in its cherry, and the processing and roasting should highlight the coffee's natural flavor nuances—its varietal, regional, and growth-specific characteristics.

Fermentation is an essential and desirable process, but it should amplify and enhance the natural coffee flavors rather than completely alter or suppress them with added flavors.

At the same time, it's interesting to observe coffee industry trends. Currently, there is a growing demand and interest from consumers in experimental coffee processing and funky fermentations. This serves as an excellent opportunity for coffee farms and growers aiming to increase their income by offering higher quality and more complex coffees. However, this often requires investments in specialized fermentation and processing equipment, which poses a risk for growers due to the substantial financial commitment. Additionally, it's a risky investment as the duration of this trend and the certainty of returns on all investments remain uncertain.

In the next journal entry, we will get a closer look at "Sancoffee." We are excited about our collaboration with our trusted partners and will outline the significance of the "Sancoffee" cooperative in the region.

 

Read the previous blog HERE.