Anaerobic Washed Variations for Gesha Developed by Finca Soledad

Fermentation is a crucial step in coffee processing, where microorganisms break down the mucilage surrounding the beans, generating compounds that define the flavor of the final product.

Anaerobic fermentation takes place in an oxygen-free environment—usually by placing whole cherries or pulped beans into sealed tanks. This environment promotes the growth of specific microbes that produce organic acids (such as lactic and acetic acids) and aromatic esters, which contribute to a cup profile that is distinct, vivid, and layered.

After fermentation, beans typically undergo a washing process to fully remove residual mucilage. This “washed” phase results in a clean, bright cup that allows the natural character of the variety and terroir to shine. Some producers, however, opt to dry the beans with the cherry intact or with partial mucilage remaining, to increase body and complexity.

The Anaerobic Washed method is a combination of:

• Anaerobic fermentation in sealed tanks
• Careful washing and slow drying

However, not all Anaerobic Washed processes are the same. Variables such as temperature, fermentation duration, cherry condition, mucilage levels, and drying conditions can be tailored for each farm or even each lot—resulting in different flavor profiles.

Driven by passion and precision, Pepe Jijón—the founder of Finca Soledad—does not apply a one-size-fits-all formula to every Gesha lot. Instead, he continually researches and refines Anaerobic Washed variants to highlight the subtlety and diversity of this renowned variety.

Variant 1: 48-Hour Anaerobic Washed

In this process, cherries are harvested at ideal ripeness with a Brix level of 22–24°, ensuring optimal sugar and organic acid content for fermentation. Whole cherries are placed into oxygen-free tanks and fermented for 48 hours under tightly controlled temperature conditions to encourage the growth of beneficial microorganisms.

After anaerobic fermentation, the beans are depulped and undergo a second 24-hour fermentation phase to further break down remaining mucilage. This enhances flavor complexity by allowing microbes to process residual polysaccharides on the parchment.

The beans are then fully washed and slow-dried in a dark, climate-controlled room for 60 days. This extended drying stabilizes the bean structure and helps preserve volatile flavor compounds developed during fermentation.

Variant 2: 30-Hour Anaerobic Washed

This variant focuses on achieving a balance between cleanliness and bright fruit notes. Cherries are placed into sealed anaerobic tanks immediately after harvest and fermented for 30 hours. The shorter fermentation time limits the production of overly strong acids or overpowering compounds, preserving Gesha’s refined character.

After fermentation, cherries are depulped, and the mucilage-covered beans undergo a 24-hour fermentation to complete mucilage breakdown without overwhelming the flavor. Drying takes place over 45 days in a dim environment with gentle airflow, ensuring even moisture loss without destabilizing the bean structure.

Variant 3: Anaerobic Washed Following an Aerobic Phase

This unique process begins with an overnight aerobic pre-fermentation phase after harvest. This stage triggers natural respiration and activates the native microbial population before anaerobic conditions are introduced, creating a stable microbial environment for balanced flavor development.

Cherries are then depulped, and the beans are anaerobically fermented in sealed tanks for 24 hours to prevent dominance by aggressive microbes. Drying lasts for 40 days—long enough for structure stabilization but quicker than the other variants, helping retain the brightness of volatile acids.

Anaerobic Natural Process

In addition to Anaerobic Washed, Finca Soledad has also developed an Anaerobic Natural method. Unlike Washed processing, the cherries remain intact throughout the fermentation and drying stages.

After harvest, whole cherries are placed in a controlled anaerobic environment for 36 hours. The oxygen level is not entirely eliminated but tightly regulated to guide microbial activity toward beneficial outcomes. This controlled micro-aerobic environment allows a smooth transfer of esters and volatile alcohols from the fruit into the beans.

After fermentation, cherries are dried for around 20 days using raised beds and patios with gentle sunlight and natural airflow, ensuring uniform and stable drying.

Compared to aerobic fermentation, anaerobic fermentation fosters the production of organic acids such as lactic acid, which increases sweetness, enhances mouthfeel, and gives the cup a vibrant and well-defined flavor.

Coffees from Finca Soledad processed via Anaerobic Washed variants typically exhibit pronounced dry and wet aromas, often with notes of peach, blueberry, strawberry, cherry, and sometimes hints of yogurt, mild spices, and soft musk.

For Gesha lots in particular, the cup is smooth and pleasant, with clearly structured sweetness and a lingering finish. Floral notes blossom in the aroma, and as the coffee cools, layers of juicy grape, citrus, bergamot, and tropical fruit unfold. The remarkable balance between bright acidity and elevated sweetness often reminds tasters of exceptional Panama Gesha lots.

XLIII Coffee is proud to partner with Finca Soledad to bring the Finca Soledad Gesha Anaerobic, produced using a refined Anaerobic Washed variant, directly to Vietnam. Stay tuned for the official launch of this extraordinary coffee!