Abstract:
Arabica coffee (Coffee arabica L.) is an economically important crop, which is contributing the highest of
all export revenues in Ethiopia. It is also the major cash crop of Jimma Zone and produced in eight
woredas. Despite the favorable climatic conditions, variety of coffee types and long history of its production
in this Zone, quality of coffee is poor due to traditional poor pre and post harvest practices. Efforts were
made so far in areas of fermentation time, drying depth, time of storage and extension support, training for
coffee expertise and coffee farmers on recommended technologies. But there is lack of profound assessment
works to identify the specific coffee quality problems in Jimma zone and lack of adequate information on the
effects of post harvest processing and handling techniques on coffee quality. Therefore, the study was
conducted with the objectives of assessing the impact of pre and post harvest processing practices on the
quality of both wet and dry processed coffee, identifying the inherent quality of coffee in the zone and
investigating socio-economic technical and institutional factors related to coffee quality problems in the
zone. For field survey, 164 household farmers were randomly selected following sample size determination
procedures of probability proportional to size technique and 30 coffee traders were purposefully selected
from the two woredas and interviewed in the study area from November to December 2008. The data
collected from the field survey were analyzed by employing the statistical procedures of SPSS version 14.0.
A binary logit model was employed for the factors affecting adoption of coffee quality pre and post harvest
management practices (CQPPHMP). A total of 14 explanatory variables were used for the binary logit
model out of which 6 variables were significant to affect the adoption of CQPPHMP practices by the coffee
farmers whereas none of the explanatory variables for sampled traders were found to be significant in the
chi-square analysis except checking quality for price. In binary logistic regression analysis of field survey
obtained from coffee farmers those factors that affect coffee quality were disease prevalent in coffee field,
compost application, mixing up of differently harvested coffee during selling, availability of storage, drying
materials used for drying and age of coffee in the store. The findings of this study indicate that any effort in
promoting and adopting of CQPPHMP practice should recognize the socio-economic, institutional, and
technical factors for better adoption of CQPPHMP practices. On the other hand, a total of 32 coffee bean
samples (16 from each woreda) were prepared for the laboratory analysis (organoleptic and bean physical
quality characteristics) at Jimma Agricultural Research Center (JARC). The laboratory experiment was
arranged in split plot design, considering the processing method as main plot and the preparation type as
sub-plot in RCBD with three replications and organoleptic quality attributes were assessed by trained coffee
panelists. The laboratory data analysis was computed by using general linear model (GLM) procedures of
SAS version 9.2. It was observed that wet processing method resulted in high mean values for good cup
quality attributes, like acidity, body and flavor, and for bean physical quality attributes, like odor as
compared to dry processing method. For most of sensorial quality attributes, recommended preparation
procedure outsmarted local preparation (farmers/traders) methods. For physical quality attributes,
preparation methods were varied only for color and odor. Nonetheless, of the processing methods
investigated in this study, it was observed that the recommended way of preparing coffee promotes the
typical quality profile to the final cup quality to meet consumers’ choice that finally creates interest for the
profile and competence in the international coffee market. From this result, it can be concluded that wet
processing method is the best approach to obtain fine and typical flavor in the cup to meet the interest and
preference of consumers. Extension intervention could be the best approach to create awareness among
coffee producers towards maintaining typical coffee quality profile of their garden through processing that
finally adds value to their produces.