Processing coffee is all about variables — controlling one while adjusting another — and three producers in Colombia have been tweaking their processing variables for years to arrive at processing protocol used both for large lots and for microlots that often see the competition spotlight. At Ally Coffee, we partner with producers who move processing innovations forward and demonstrate expertise in methods that have proven themselves over time.
Hacienda El Obraje in Tangua, Nariño
Hacienda El Obraje, Nariño
Pablo Andres Guerrero has been growing coffee on his family’s Hacienda El Obraje since the year 2000, when the farm made its next transition in an evolution from wheat to apples to coffee, and began fully processing Obraje’s coffee after the construction of a wet mill and drying facilities in 2009.
According to Pablo, “Experimenting with fermentation has been quite interesting. We have tried different times and temperatures, first with the cherries and after with the beans. I have learned many things. It’s important to have always the same quantity of coffee during the fermentation process, or at least give the coffee similar conditions of space and temperature.”
Obraje processes Natural and Washed coffees and has spent a decade perfecting these two pathways for its Caturra, Gesha, and now Yellow Bourbon, Castillo, and Maracaturra varieties.
Washed Processing: All processing times vary according to the variables of climate at the time of harvest. Normally, cherries are fermented for 20 hours in cherry in the same bags pickers use. Cherries are selectively harvested for ripeness and also sorted by flotation. After depulping, coffee is dry fermented for another 24 hours and then fully washed, concluding with a second flotation sort.
Washed coffee typically dries for an average of 16 days on raised beds or four days in the mechanical parchment combustion dryer, where it receives a hot air flow of 30 degrees Celsius. This style of “oven dryer” exposes coffee to warm air currents above and below the beans.
Natural Processing: All processing times vary according to the variables of climate at the time of harvest. Coffees destined to be Natural processed are normally fermented for 20 hours in cherry in the same bags the pickers use, then flotation-sorted before being moved to raised beds to dry. Drying typically takes 30 days for Naturals. Take a virtual farm tour of El Obraje.
Finca Monteblanco, San Adolfo, Huila
Finca Monteblanco, Huila
Finca Monteblanco first made a name for itself with the Pink Bourbon variety producer Rodrigo Sanchez found growing on his farm, but Rodrigo treats processing as an ongoing opportunity for discovery and invention and Monteblanco has built a lasting reputation for consistently producing coffees that showcase the best of innovative processing. Taking inspiration from the wine industry, he sought to find the optimal balance between fermentation temperature and sugar levels in the coffee cherries. Rodrigo and his team developed a system for measuring the degrees Brix for each lot of harvested cherries and then assigning them a processing style based on the sugar level.
Pink Bourbon variety and washing canals
Solar dryer and Rodrigo in the field
One of the more innovative processing styles pioneered by Monteblano as part of this system was Cold Fermentation, which refrigerates depulped coffee to prolong the time the mucilage is in contact with the bean. In 2019, Rodrigo released several new methods of washed processing, including one to bring out balanced tannin levels in coffee.
1. Cherries are collected when they reach 28° Brix and floated to sort out defects.
2. Next, cherries are packed in GrainPro bags and left to oxidize for 120 hours.
3. Cherries are depulped and again placed in GrainPro bags for another 80 hours, reaching temperatures of 47° and a pH of 3
4. Coffee is fully washed and taken directly to the solar dryer for 3–4 days
5. Coffee completes the drying process on shaded beds for 20–25 days
Cauca’s landscape
INDESTEC Finca El Paraiso, Cauca
Diego Samuel Bermudez Tapia is one of the partners in INDESTEC, Innovacion y Desarollo Tecnologico para el Agro; Innovation and Technological Development for Agriculture. INDESTEC develops processing equipment and techniques to control the variables in coffee processing. Diego’s Finca El Paraiso in Piendamo, Corrigimiento de Tunia, Vereda los Arados is the site of ample coffee processing innovation. Their Eco-Enigma drying technology operates through closed circuit air recirculation and controlled temperature. Drying temperature is programmed according to the flavor profiles Diego has developed by following various “recipes” for different fermentation and drying stages at precise temperatures for pre-determined lengths of time. Red Plum and Lychee are two of these profiles.
Red Plum
- Anaerobic fermentation in cherry for 48 hours at 18 degrees Celsius in tanks with a pressure release valve.
- Depulping
- Second anaerobic fermentation in mucilage for 48 hours at 120 degrees Celsius.
- Thermal shock wash, first with water at 40 degrees then with water at 12 degrees.
- Controlled drying for 34 hours at 35 degrees to drop the relative humidity from 25% to the desired level between 10%-11%. Drying takes place in INDESTEC’s Eco-Enigma machine through condensation and air recirculation.
Lychee
- Anaerobic fermentation in cherry for 48 hours at 18 degrees Celsius in tanks with a pressure release valve.
- Depulping
- Second anaerobic fermentation in mucilage for 96 hours at 18 degrees Celsius
- Thermal shock wash, first with water at 40 degrees then with water at 12 degrees.
- Controlled drying for 34 hours at 35 degrees to drop the relative humidity from 25% to the desired level. Drying takes places in INDESTEC’s Eco-Enigma machine through condensation and air recirculation.
Processing, Center Stage
On the coffee competition stage, competitors have limited time to tell a coffee’s story and describe how these careful stages of processing translate to flavors perceived in the cup. The techniques, approaches, or types of equipment spotlighted in competition presentations are just the tip of the iceberg in terms of processing information.
At its simplest, coffee processing is intuitive, with producers monitoring weather conditions and moving coffee between patios, raised beds, covered solar dryers, and mechanical dryers until the beans reach the desired level of humidity. At its most complex, processing involves hourly record keeping of metrics like temperature and pH, custom built tanks with valves and gauges, and constant adjustments to keep everything on track.
No method is right or wrong, and many producers turn to reliable processing methods for the majority of their harvest while experimenting with small lots to see what else might yield a desirable result. Competitions are chances to push the limits of what is possible in coffee while always keeping in mind the hospitality experience of the final coffee drinker. Simple or complex, classic or innovative, taking note of the processing used to produce a given coffee always serves as a reminder of the natural variability of working with a crop that responds to even slight changes in its conditions.
Monteblanco drying bed log.