But is it the type of bean, the manner in which it is grown, or the manner in which it is processed that maximizes every last drop of coffee?
Recent research on this topic was published in the Agrosystems, Geosciences, and Environment journal. The journal is an American Society of Agronomy and Crop Science Society of America publication.
Ethiopian researcher Addis Alemayehu and a research team from the Southern Agricultural Research Institute studied Arabica coffee. Ethiopia is the leading producer of coffee beans in Africa, and Arabica is the dominant variety.
“Arabica coffee is an integral part of the tropical forest agroecology in southwest Ethiopia,” says Alemayehu. “The forest ecosystems provide favorable conditions for producing coffee of exceptional quality. In addition, they are a valuable source of income for farmers.”
Alemayehu states, “Coffee production and processing systems are the primary determinants of the overall quality of coffee produced in a given environment.”
Numerous factors affect the development and growth of coffee plants, including:
altitude, rainfall pattern, temperature, relative humidity, light, soil moisture, and nutrient content all play a role in soil fertility.
These factors then affect the quality of the bean and the biochemicals within the bean that affect the quality of the coffee.
The Kaffa Zone in Ethiopia’s southwestern region is home to a variety of coffee-growing ecosystems.
Researchers gathered red coffee berries and investigated the impact of various processing techniques on coffee quality.
The research group examined coffee plantations from three distinct regions. All the regions were contained within the Kafa Biosphere Reserve in the Kaffa Zone of Ethiopia’s southwest. The growing regions ranged in height from over 1,500 feet (equivalent to the Camelback Mountains in Arizona) to over 11,000 feet (similar to the Wasatch Mountain Range in Utah). Temperature and precipitation varied by location, as did growing techniques. This provided the team with information regarding production and growth patterns that may affect coffee bean quality.
To examine the effect of bean processing on bean quality, the team collected ripe cherries (unprocessed beans) from October to December 2018 at study sites. Each sample was divided into three equal portions for application of dry, semi-dry, and wet processing:
Dry processing indicates sun-dried coffee cherries.
Wet processing involves the mechanical pulping of coffee cherries. As part of the wet processing technique, the beans are then fermented.
Semi-wet processing involves machine-pulping and hand-washing coffee cherries, followed by sun-drying parchment coffees with a mucilage coating.
Professional coffee tasters took part in the research’s testing phase. They took part in the physical, raw, and cup examinations.