Introduction:The anaerobic slow natural processing method used by Donkey Estate once achieved the astonishing record score of 95.25 for a natural coffee, while its washed batch also earned 95 points, showcasing extraordinary potential. This article delves into its ASD anaerobic slow drying process—from five days of anaerobic fermentation to five weeks of slow drying—to explore how this technique shapes intense wine-like and cocoa flavors. We also analyze the unique expressions of coffees from different altitudes and varieties, helping you understand the processing secrets behind top-tier coffees.
In the world of specialty coffee, processing methods are often the key to flavor expression. In a 2019 competition, Donkey Estate’s naturally processed beans won a high score of 95.25, setting a record for that year, while its washed batch also scored 95, both setting new benchmarks. Such achievements rely on a sophisticated and rigorous processing technique—anaerobic slow drying, also known as the ASD process.
The Ramasutus family, led by young Wilford Ramasutus, who was responsible for this innovative processing, chose to place the freshly harvested coffee cherries in sealed, oxygen-free tanks for a five-day fermentation. This process effectively suppresses the growth of undesirable microorganisms and guides the fermentation toward a more controllable and richer direction, thereby nurturing complex wine-like and chocolatey flavors.
After fermentation, the coffee beans did not undergo the traditional rapid drying but instead entered a long and delicate drying phase—lasting a total of five weeks. This slow dehydration process helps stabilize the internal flavor development of the beans and reduces the occurrence of off-flavors. Wilford emphasized in an interview: “Most coffees only need two to three weeks to sun-dry, but we opt to extend the drying time and meticulously control every step to ensure the final cup delivers pure, clean flavors.”
The charm of the ASD process lies in its ability to produce distinctly different flavor profiles based on the coffee’s growing altitude and variety. For coffees grown at altitudes below 1700 meters or those that are not Gesha varieties, this anaerobic fermentation paired with slow drying often brings out intense wine-like aromas with wine-toned notes, along with hints of cocoa or the rich body commonly found in Nicaraguan coffees. These layered flavors make the cup more full-bodied and enhance the overall drinking experience.
However, for Gesha varieties grown at high altitudes, the ASD process reveals another nuanced trait. Although also undergoing anaerobic and slow drying, high-altitude Gesha does not develop overly strong alcoholic notes. Instead, it presents a more elegant red wine aroma, even with subtle hints of cherry liqueur. This expression not only adds complexity to the flavor but also fully preserves the Gesha variety’s inherent clarity and cleanliness, allowing it to still demonstrate high definition and layering in cupping.
In reality, the core of the ASD process lies in the word “control.” From establishing the anaerobic environment and regulating fermentation temperature and humidity to daily turning and moisture monitoring during drying, every step must be executed precisely to ensure the final flavor’s balance and elegance. For coffee enthusiasts, understanding these processing details not only allows for a deeper appreciation of coffee flavors but also provides clearer guidance when selecting beans that match their taste preferences.
In summary, Donkey Estate’s anaerobic slow natural processing method is a top-tier technique that combines science and experience. Through five days of anaerobic fermentation and five weeks of slow drying, it not only creates rich and layered wine-like and cocoa tones but also showcases diverse flavor expressions based on different altitudes and varieties. If you’re a coffee lover pursuing depth of flavor and unique character, this ASD-processed coffee is definitely worth savoring in detail.
The above content is compiled by CoffeeHunters, a coffee news website.
