Diego Bermudez, “Thermal Shock” from Cauca, Colombia

Variety: Castillo
Main process: Double fermentation at a low temperature with a thermal shock washing (cold and warm water).

1. Harvesting of 95% ripe cherries, 5% pinto cherries (semi-ripe).
2. First washing of the cherries with filtered water (traditional filtering system, a reverse osmosis filter and a UV-C filter) to reduce the microbial load.
3. First phase of fermentation (& inoculation of microorganisms) – Anaerobic lactic fermentation (in cherries). It consists of 48 hours of fermentation in anaerobic bioreactors with a pressure relief valve at a temperature of 18 Celsius degrees. It includes the use of selected microorganisms according to their sensory profile.
4. Second phase of fermentation – Aerobic fermentation (with pulped cherries). This phase consists of adding the yeast culture medium to the mucilage and passing it to an aerobic phase in a rotary fermenter for its homogenization. The fermentation medium contains different flavor precursors and aromas generated mainly by the microorganisms. This phase lasts for 48 hours and occurs at 21 degrees Celsius.
5. Thermal Shock Washing first with hot water (40 Celsius degrees) and then cold water (12 Celsius degrees). This allows the membranes and pores of the coffee beans to expand rapidly and fix the fermentation compounds around the coffee beans (those secondary aromas developed in the different phases of fermentation of the culture medium). (Fun fact: the term “Thermal Shock” has been coined by Diego himself).
6. Controlled drying process to guarantee the final quality of the coffee. This phase lasts 34 hours, with air recirculation at a temperature of 35 Celsius degrees and relative humidity of 25%, until the grain reaches a humidity of between 10% and 11%. (Some compounds generated in the fermentation phases and present in the coffee genetically are highly volatile or thermolabile). Therefore, it is essential to carry out a careful drying process with the coffee seeds. For this task, the company has developed its own technology for drying in an inert atmosphere at low temperatures.

The Geisha varieties adapted to the Cauca region feature a delicate, citric, and aromatic profile. The climatic conditions, altitude, terroir, and abundant rainfall contribute to the outstanding quality of this variety.

Process: Washed with a special type of fermentation
Fermentation: Double, anaerobic at low temperature
Microorganisms used: Saccharomyces Carlsbergensis
Technique: Washed with thermal shock (using warm and cold water) 

To begin, the cherries undergo a disinfection process using ozone, reducing any unwanted microbial presence. Subsequently, the cherries are transferred to stainless steel fermenters where CO2 displaces oxygen, preventing oxidation of the coffee compounds within the pulp. 

The initial fermentation takes place at 18 degrees Celsius and 20psi for 36 hours. During this period, the added yeast Saccharomyces Carlsbergensis produces various esters. Finca El Paraiso possesses a collection of isolated and selected microorganisms, chosen for their specific sensory profiles during fermentation.

Before inoculating the microorganisms into the coffee masses, a phase called biocatalysis of precursors occurs. This process generates the necessary conditions to induce cellular stress and enhance the biosynthesis of aromatic fermentation compounds, including esters, aldehydes, and alcohols. These reactions last for 36 hours in stirred tank bioreactors, employing a fed-batch operation with mucilage feeding.

The second fermentation takes place with pulped coffee. Here, the yeast culture medium is introduced into the mucilage, with a ratio of 250 mL/kg of culture medium. The process transitions to an aerobic phase in a rotary fermenter to achieve optimal homogenization. The resulting secondary metabolites primarily remain in the leachates, as the parchment and silver film covering the coffee beans are resistant to penetration. To retain these fermentation compounds, a thermal shock washing technique is employed. This technique rapidly expands the membranes and pores of the coffee beans, fixing the fermentation compounds and preventing their loss during the washing process.

The final phase involves controlled drying at a low temperature using dehumidifying systems. This meticulous drying process ensures the preservation of the coffee’s exceptional quality.

Fermentation: Double aerobic
Microorganism: Saccharomyces Cereviseae 
Technique: Washed with thermal shock 
Process: semi-washed with culturing

1. Harvesting cherries at its optimum point of ripeness and highest amount of sugars, precursors of aromas and flavors
2. Disinfection of cherries with ozone 
3. First anaerobic fermentation – 48h in water with Saccharomyces Cerevisiae culture medium. 
4. Depulping & adding of culture medium  – After pulping the cherries, a culture medium with yeast  is added to produce the precursor of aromas and flavors of the profile. Then a leachate recirculation is carried out. 
5. Thermal shock washing – This allows the membranes and pores of the coffee beans to expand rapidly and fix the fermentation compounds around the coffee beans (those secondary aromas developed in the different phases of fermentation of the culture medium). (Fun fact: the term “Thermal Shock” has been coined by Diego himself).
6. Drying process in de-humidifier – this removes humidity avoiding over-oxidation and preserving the soft notes of coffee beans. to guarantee the final quality of the coffee. This phase lasts 34 hours, with air recirculation at a temperature of 35 Celsius degrees and relative humidity of 25%, until the grain reaches a humidity of between 10% and 11%. (Some compounds generated in the fermentation phases and present in the coffee genetically are highly volatile or thermolabile). Therefore, it is essential to carry out a careful drying process with the coffee seeds. For this task, the company has developed its own technology for drying in an inert atmosphere at low temperatures.
7. Stabilization and storage in a cool place
8. Hulling and selection according to the quality standard.

Fermentation: Aerobic and anaerobic
Microorganism: Yeast Paraiso Yellow Fruit  
Technique: Washed with thermal shock 
Process: Semi-washed with special fermentation 

1. Harvesting cherries at its optimum point of ripeness 
2. Disinfection of cherries with ozone 
3. First anaerobic fermentation – 72h in water 
4. Depulping & demucilaging – The mucilage and pulp are taken to the pilot plant to carry out the production of specific microorganisms for the process and for the production of culture medium (which contains flavors and aromas produced in the fermentation. 
5. Second fermentation with added culture medium – 36 hrs . This step is needed to fix the precursor to the coffee beans thanks to pressure.
6. Thermal shock washing – This allows the membranes and pores of the coffee beans to expand rapidly and fix the fermentation compounds around the coffee beans (those secondary aromas developed in the different phases of fermentation of the culture medium). (Fun fact: the term “Thermal Shock” has been coined by Diego himself).
7. Drying process in de-humidifier – this removes humidity avoiding over-oxidation and preserving the soft notes of coffee beans. to guarantee the final quality of the coffee. This phase lasts 34 hours, with air recirculation at a temperature of 35 Celsius degrees and relative humidity of 25%, until the grain reaches a humidity of between 10% and 11%. (Some compounds generated in the fermentation phases and present in the coffee genetically are highly volatile or thermolabile). Therefore, it is essential to carry out a careful drying process with the coffee seeds. For this task, the company has developed its own technology for drying in an inert atmosphere at low temperatures.
8. Stabilization and storage in a cool place
9. Hulling and selection according to the quality standard. 

Fermentation: Double anaerobic
Microorganism: Yeast yellow fruit
Technique: Washed with thermal shock 
Process: Semi-washed with special fermentation

1. Harvesting cherries at its optimum point of ripeness
2. Disinfection of cherries with ozone 
3. First anaerobic fermentation – 36h in water
4. Depulping and demucilaging. The mucilage and pulp are taken to the pilot plant to carry out the production of specific microorganisms for the process and for the production of culture medium (which contains flavors and aromas produced in the fermentation. 
5. Second fermentation with added culture medium – 20 hrs . This step is needed to fix the precursor to the coffee beans thanks to pressure. 
6. Thermal shock washing – This allows the membranes and pores of the coffee beans to expand rapidly and fix the fermentation compounds around the coffee beans (those secondary aromas developed in the different phases of fermentation of the culture medium). (Fun fact: the term “Thermal Shock” has been coined by Diego himself).
7. Drying process in de-humidifier – this removes humidity avoiding over-oxidation and preserving the soft notes of coffee beans. to guarantee the final quality of the coffee. This phase lasts 34 hours, with air recirculation at a temperature of 35 Celsius degrees and relative humidity of 25%, until the grain reaches a humidity of between 10% and 11%. (Some compounds generated in the fermentation phases and present in the coffee genetically are highly volatile or thermolabile). Therefore, it is essential to carry out a careful drying process with the coffee seeds. For this task, the company has developed its own technology for drying in an inert atmosphere at low temperatures.
8. Stabilization and storage in a cool place
9. Hulling and selection according to the quality standard.

Fermentation: Double anaerobic
Microorganism: Kluviromices Lactis
Technique: Washed with thermal shock 
Process: Washed with special fermentation

1. Harvesting cherries at its optimum point of ripeness
2. Disinfection of cherries with ozone 
3. Anaerobic fermentation – 72h in water and Lactobacillus in milk culture medium.
4. Depulping – The coffee is depulped and mixed with the leachate (collected in the fermenting cherries), this increases the level of precursors in the seeds. 
5. Thermal shock washing – This allows the membranes and pores of the coffee beans to expand rapidly and fix the fermentation compounds around the coffee beans (those secondary aromas developed in the different phases of fermentation of the culture medium). (Fun fact: the term “Thermal Shock” has been coined by Diego himself).
6. Drying process in de-humidifier – this removes humidity avoiding over-oxidation, and over-fermentation, by stopping the metabolic processes.  A controlled drying process preserves the soft notes of coffee beans. Therefore, it is essential to carry out a careful drying process with the coffee seeds. For this task, the company has developed its own technology for drying in an inert atmosphere at low temperatures.
7. Stabilization and storage in a cool place
8. Hulling and selection according to the quality standard.