Which Coffee Processing Method Changes Flavor Most?
Natural, washed, and honey are the three common coffee processing methods, and each gives a distinctly different flavor profile. All involve some degree of fermentation. Washed tends to read cleaner, natural tends toward fruit, and honey sits between the two, depending on how much mucilage is left on the seed.
Enzyme and anaerobic processing have entered wider use more recently. Anaerobic fermentation borrows from winemaking: beans go into a sealed tank, carbon dioxide pushes out oxygen, sugar breakdown slows, and pH falls more gradually, extending fermentation. Used in moderation the technique adds flavor; used to mask defective beans, it departs from the purpose of processing.
The flavor of coffee depends to a large extent on the processing method of the green beans. Washed, natural, and honey processing, as the three classic methods, each present distinctly different flavor profiles. In addition, enzyme processing and anaerobic fermentation have gradually entered the public eye in recent years, adding more possibilities to coffee. Front Street Coffee believes that the moderate use of such fermentation techniques to create distinctive flavors is commendable, but if they are used to mask defects in the coffee beans themselves, that deviates from the original purpose of processing methods. This article will systematically sort out the specific procedures and flavor characteristics of these processing methods, and combine them with representative products on Front Street Coffee's bean list to help coffee enthusiasts build a clearer understanding.
For more specialty coffee knowledge, please follow the WeChat public account: Front Street Coffee (FrontStreet Coffee) The three most common processing methods for coffee beans are natural, washed, and honey. Regardless of which one is used, they all involve varying degrees of fermentation. Enzyme processing, meanwhile, builds on washed processing and uses strains with different mechanisms to shape richer flavors through the principles of fermentation. Front Street believes that if this fermentation method is used only on a small scale to create some uniquely flavored coffee beans to attract consumers, its role is positive; but if it is used on a large scale to cover up the defects of the coffee beans themselves, rather than improving coffee quality through cultivation techniques and variety improvement, then that is inappropriate. So how exactly is enzyme processing carried out? Enzyme processing is usually carried out in tandem with anaerobic processing. The anaerobic fermentation process originates from winemaking. Specifically, coffee beans are placed in a sealed container, and carbon dioxide is injected to expel oxygen. Under oxygen-free conditions, the decomposition rate of sugars in the coffee mucilage slows down, and the pH value drops more slowly as well, thereby extending the fermentation time and developing better sweetness and a more balanced flavor, ultimately producing a coffee bean with a unique style. The prerequisite for implementing anaerobic fermentation is the availability of a fully sealed, opaque container that can be monitored. The container is placed indoors, and indoor temperature is strictly controlled. By adjusting temperature and time, the degree of fermentation in the container is controlled.
The enzyme anaerobic processing method first removes defective floating beans through washing, then adds specific enzyme groups during anaerobic fermentation for co-fermentation. After fermentation is complete, the mucilage on the surface of the coffee beans is removed by washing, after which the coffee beans are dried by machine drying or shade drying to avoid excessive secondary fermentation caused by high temperatures during sun drying, which could produce undesirable flavors. This processing method is called anaerobic enzyme washed.
On Front Street Coffee's bean list, the Front Street Rose Valley coffee from Colombia's Grand Tree Estate uses anaerobic double enzyme washed processing. The so-called double enzyme means that enzymes are added twice during a single anaerobic fermentation process, enhancing both the aroma and acidity of the coffee beans.
Front Street Colombia Grand Tree Estate Rose Valley Coffee Beans Estate: Colombia Grand Tree Estate Region: Santander Region Processing Method: Anaerobic Double Enzyme Washed Altitude: 1700m Variety: Caturra [Front Street Colombia Grand Tree Estate Rose Valley] Brewing Flavor: The sweetness of peach, accompanied by the aroma of roses, with both the high-quality sweet-and-sour sensation of black grapes and the silky mouthfeel of cream toffee, followed by a finish reminiscent of liqueur chocolate aroma. How does the washed processing method process coffee beans? After the coffee cherries are harvested, they are immediately sent for processing, usually completed within 6 to 12 hours after picking. The coffee cherries are first weighed, then immersed in water, in order to select unripe floating green cherries and defective beans.
The coffee cherries are then sent to a pulping machine for depulping, a step designed to remove the skin and pulp of the coffee cherries. The coffee cherries with the pulp and skin removed are transferred to fermentation tanks or fermentation barrels and left to ferment for 18 to 36 hours, during which enzymes break down the mucilage and pectin in the coffee cherries. After demucilaging, the coffee cherries are washed in the tank with an appropriate amount of water. During washing, the pectin breakdown substances on the surface of the coffee beans are removed by agitation. After washing is complete, only the parchment layer, silver skin, and green beans remain. The washed coffee beans are sorted to remove defective beans, then immediately sent to drying areas (such as tarps, concrete patios, raised beds, etc.) for drying. The drying time depends on factors such as the environmental climate, generally ranging from 5 to 14 days. At this point, the moisture content of the coffee beans drops from 55% to 11%. The dried coffee beans are called parchment coffee, that is, green coffee beans with the parchment layer still attached. Parchment coffee is sent to warehouses for storage, and hulling is carried out before export, finally yielding the green beans we need.
Front Street believes that washed coffee beans best highlight the cleanliness of coffee. Washed coffee has relatively pronounced acidity, better cleanliness, medium body, and the most consistent green bean quality. The Yirgacheffe region of Ethiopia most prefers washed processing, in order to highlight the bright acidity and rich floral and fruity aromas of Yirgacheffe coffee beans.
Ethiopia Yirgacheffe · Front Street Gedeb Cooperative Coffee Beans Region: Yirgacheffe Gedeo Zone Region Altitude: 1900-2300m Variety: Heirloom Processing Method: Washed Grade: G1 [Front Street Yirgacheffe Washed Gedeb] Brewing Flavor: Citrus and black tea on the palate, with cream, caramel, and almond in the finish as the temperature changes; the sweet aftertaste is obvious and the mouthfeel is clean and sweet. How does the natural processing method process coffee beans? After harvesting, the coffee cherries first undergo manual hand sorting to remove defective coffee cherries, including overripe, underripe, and insect-damaged ones, as well as foreign matter other than the cherries.
The sorted coffee cherries are sent to drying areas for drying. Different regions may use different drying racks; some use tarps, some use raised beds, and some use concrete patios, etc. The drying time averages 3 to 4 weeks, until the moisture content of the coffee drops to 11%, which marks the completion of the drying process. The dried coffee cherries are sent to a processing plant for depulping and hulling, and may even be polished. The skin, pulp, and other parts are all removed at this step.
After depulping, the green coffee beans are sorted again to remove beans with poor appearance. This step reflects the quality of the coffee drying process: over-dried coffee beans are more fragile and will be broken into fragments during depulping; under-dried coffee beans contain too much water, and the excessive moisture activity makes them prone to bacteria and mold. After sorting, they are sent to warehouses for storage until export. Front Street believes that natural processing can highlight the smoothness of coffee. It is fuller-bodied than washed processing, its acidity is mostly expressed as a juicy sensation, and the coffee's sweetness is pronounced. The Sidamo region of Ethiopia most prefers natural processing, in order to highlight the region's rich berry acidity and the sweetness brought by ripe berries.
Front Street Ethiopia Sidamo Natural Huakui Coffee Beans Region: Guji Hambela Processing Station: Buku Able Altitude: 2250-2350 meters Variety: Local Heirloom Grade: G1 Processing Method: Natural [Front Street Sidamo Natural Huakui] Brewing Flavor: Citrus acidity, full berry juice sensation, lemon black tea tea-like body, lasting sweetness. How does honey processing process coffee beans? Honey processing is a green bean processing method between natural processing and washed processing. The degree of sweetness in honey processing depends on the setting of the pulper, which removes the pulp. The more pulp and pectin retained, the more pronounced the sweetness of the honey process. Why is that? A coffee cherry consists of skin, pulp, pectin, parchment, silver skin, and the seed (coffee bean). The pulp and pectin in the coffee cherry are the parts with the highest sugar content in the entire coffee bean. Therefore, during honey processing, how much pulp and pectin are retained affects how much sugar from the pulp and pectin is transformed during the drying process. But Front Street believes this also brings drawbacks, because the high sugar content accelerates the fermentation of pulp and pectin at high temperatures. If not strictly controlled, mold and over-fermentation are likely to occur.
[Black Honey Processing] Almost no pectin is removed, so drying takes the longest, requiring more than 14 days. During the process, to avoid drying too quickly, coverings are used to block excessively strong sunlight so that sugar conversion is more complete. [Red Honey Processing] Retains 80% pectin (specific practices vary by estate), sun drying lasts about 12 days, and shade canopies may also be used during the process. [Yellow Honey Processing] Retains 40-60% pectin, receives the most sunlight during drying, lasting about 8 days. [White Honey Processing] Retains 40-60% pectin, and during drying is spread more thinly on raised beds, so the drying time is shorter. Front Street believes that honey-processed coffee beans have better flavor, with balanced acidity and sweetness, and because they have been exposed to sunlight, the coffee beans' own aroma is also amplified, with a rich, mellow taste. The honey processing method formally emerged in Central and South American regions such as Costa Rica and El Salvador, and is now widely used in Costa Rica.
Front Street Costa Rica Tarrazu Yellow Honey Process Coffee Beans Region: Costa Rica Tarrazu Variety: Caturra, Catuai Processing Method: Yellow Honey Processing Altitude: 1500m [Front Street Costa Rica Tarrazu Yellow Honey Process] Brewing Flavor: Obvious fermented aroma on the palate, citrus acidity, and a chocolate-like smoothness in the mid-palate.
The above content is compiled by CoffeeHunters, a coffee news website.
