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Finca El Arbol, Natural - Grey Roasting Co

Finca El Arbol, Carbonic Maceration Natural

Finca El Arbol, Carbonic Maceration Natural


Nashi Pear, Guava, Cherry, Molasses, Green Grape, Cacao, Floral

Carbonic Maceration Natural


  • Hand sorting of only ripe, red cherries at 20-22 brix
  • Cherries are placed inside sealed tanks and filled with CO2 pushing oxygen out
  • Controlled yeast activity, temperature & humidity of tanks
  • Extended coffee-skin contact and anaerobic fermentation time intensifies fruit characters bringing deep fruit flavours and rich mouthfeel and length to the cup
  • Removed from tank and rinsed, then laid on raised beds
  • Drying takes typically 20-25 days

In 2016, World Barista Champion and the founder of ONA Coffee, Sasa Sestic, teamed up with a couple of local Nicaraguan producers to buy Finca El Arbol. The goal was to plant new and exciting varietals and to experiment with processing methods to create new flavour experiences. On top of this, processing and varietal ‘recipes’ are spread to neighbouring farms to help improve the whole surrounding community in Diplito.

The name “El Arbol” comes from the giant tree that dominates the centre of the farm and this is one of three farms in Central America either owned or part-owned by Sasa. He works very closely with a company called Bridazul. “Brida” commonly refers to a cable tie or clamp but a more general meaning is “to tie or connect”. “Azul” means blue (the dominant colour of the Nicaraguan flag), so the combination of these two words is used to symbolise the connection between what happens at a coffee farm all the way to the end user, and being able to trace and understand every step of the process.

The farm is on track to become fully organic by around 2025 as they slowly reduce the use of chemicals that are currently being used to fight la roya (leaf rust). These chemicals are helping to strengthen the soil but are gradually being replaced with organic compost from local animals, trees, vegetables and flowers. The aim is to increase biodiversity on the farm and in the local area, so that the natural environment itself returns to being self-sustaining and nutrient rich. This will hopefully also ensure high quality coffee production so that the farm can fully support full time, all year workers.

The workers at Finca El Arbol are one of the defining differences of this farm. All meals are cooked on the farm and both the managers and the workers eat together. Basic healthcare is provided to all staff (including access to a dentist) and children of workers are provided with tutors to boost computer and English skills.


The Carbonic Maceration (CM) process was first introduced to the world by Project Origin founder, Saš a Š estić during the 2015 World Barista Championship in Seattle. Since then, Project Origin has researched and developed a range of CM techniques in a variety of countries. In 2018 PO started to do experimental lots with the Meteku washing station, obtaining very positive results.


Coffee cherries are picked perfectly ripe, hand sorted and floated to remove unripe and over-ripe cherries. The Washed CM Selection coffees are then pulped before being placed in temperature and humidity controlled tanks flushed with carbon dioxide (CO2) to remove oxygen from the tank. Natural CM Selection coffees are placed in the tanks still in the cherry. By controlling the fermentation we are able to introduce different kinds of yeast production in the tanks and control how they interact with the coffee, giving us very exciting results in the final cup. One key yeast that we activate is called saccharomyces cerevisiae. With the CM process we take control of how fast or slow sugars are broken down from the mucilage by the yeast. Depending on which controls we apply we are able to create unique flavour experiences and enhance different qualities in different lots.


The terms that we are accustomed to in the coffee world include natural, washed, honey, semi-washed and so on. These processing techniques use a variety of methods to extract the green beans/seeds from the coffee cherries. The CM process does not replace these methods; rather it adds another step in processing. For example, the CM Selections coffees are still identified as being natural, washed etc. but we also include the maceration process as well. So instead of being just washed, we say that a CM Selections coffee is Carbonic Macerated (CM) Washed.