ETHIOPIA | GUJI CM 0407 | CARBONIC MACERATION | LIGHT ROAST
- Country: Ethiopia
Elevation: 1950-2300 m.a.s.l.
Harvest: November - February
Process: Carbonic Maceration Natural
- LIGHT ROAST
Carbonic Maceration: A process using a controlled, carbon dioxide-rich environment to ferment coffee
The Carbonic Maceration (CM) process was first introduced to the world by Project Origin founder, Saša Šestić 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 sacromises 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.
- Coffees grow in small farmers backyards, known as “Garden coffee”
- Hand sorting of only ripe, red cherries at 20-22 brix
- Coffee cherries 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 12-15 days