Effect of methods of processing on raw and intrinsic quality of Sidama and YirgaCheffee coffee types

Coffee quality can be affected by variety, climate and soil factors, field management practices and post-harvest handling and processing techniques. Arabica coffee (Coffea arabica L.) is an economically important crop, which is contributing the highest of all export revenues in Ethiopia. The objective of study was to examine the effect of methods of processing on raw and intrinsic quality of Sidama and Yirgacheffee coffees and to identify the best method of processing that can keep the inherent quality of Sidama and Yirgacheffee specialty coffee. The study was undertaken in Dilla zuria and Yirgacheffee districts, representing the known Sidama Yirgacheffee coffee brands, respectively, in South Nations, Nationalities and Peoples’ Regional State. Fully ripe red cherries were hand collected from local coffee types. The harvested cherries were separately studied under three processing methods (washed, semi-washed and sundried) at the two locations. In each case, the treatments were arranged in factorial experiment in completely randomized design with three replications. Data on intrinsic quality (shape and make, color, odor, acidity, body, flavor and cup quality) were recorded. The result indicated that the shape and make of green bean, the other quality parameters (color, odor, acidity, body, flavor and cup quality and total quality) were significantly different due to methods of processing at both sites. Among the processing methods, wet processing resulted in superior coffee quality as compared to others at the two study areas. In addition, most quality traits significantly differ due to the interaction effects arising from location and processing method. The results also demonstrated that Yirgacheffee coffee was better than Sidama coffee type in terms of raw quality attributes, possibly due to positive effect of increased altitude in terms of quality attribute. The present findings would help optimum processing practices to be applied at each locality and thus improve the inherent quality of Sidama and Yirgacheffee specialty coffees as the faces of increasing market demand for best coffee type. Studies should be undertaken on physical and sensory attributes, other compounds and biochemical constitutes (caffeine, sugar, etc) with view of mapping the quality profile of Sidama and Yirgacheffee coffees grown under the various sites and environmental conditions.