Finca Ayutepeque: Santa Rosa Acaia - Four Way Process Experiment

All coffee is harvested as a cherry, (not actually a cherry, but the name typically used when referring to coffee as a fruit). In spanish, it is called "uva," which means grape. 

As a fruit, coffee is comprised of seven layers, and the "method of processing," simply refers to the different names given to the differing number of layers removed or left intact, when wet milling the bean, prior to drying the coffee, and it's subsequent hulling process, leaving it ready to be roasted as "green coffee," which is composed of the first three layers. 

Within our wet mill, we process coffee with four different methods. Each of those individual methods, produces a different profile for the coffee. In years passed, we have experimented with the effects of each of the four process methods on a single batch of coffee, for multiple varieties of coffee, including red bourbon, yellow boubon, pacamara, and kenia. 

This year, we look to analyze the different profiles, illuminated by processing, in the Acaia variety. Below, each of the different methods is listed, with a description of the procedures performed within each. 

In future posts, we hope to go into greater depths about the specifics of how each processing method influences not only the cup quality, but also drying time/characteristics and storage quality, months after the drying has taken place. 

1. Natural

Coffee cherries can be washed and run through a mechanical syphon to get rinsed and sorted as sinkers or floaters, or bypassing all machinery, and spread directly onto the patios following harvesting, (including those left on the tree to dry). 

Either way, the coffee is dried with the whole cherry still remaining, layers 1 - 7.

2. Pulp Natural

After being depulped, the parchment is spread directly onto the patios. 

Parchment is dried with its mucilage still on the bean, with layers 1 - 5. 

3. Machine Washed

As a continuous process, the coffee, after being depulped, is mechanically washed by a De-Mucilager.

Parchment is dried without the mucilage, with layers 1 - 4. 

4. Full Washed

Coffee parchment, after being depulped, is soaked for up to 36 hours in water; called a fermentation tank, allowing the mucilage to break down naturally over time. Once fermentation takes place, the coffee is rinsed, to remove any remaining mucilage, then spread onto the patio.

Parchment is dried without the mucilage, with layers 1 - 4.