Résumé
In Kenya coffee quality is determined by the grade proportions and beverage quality which are influenced by various factors including variety, shade and altitude. The objective was to characterize the quality of coffee produced by farmers producing traditional varieties and Ruiru 11 under shade or under full sun in Muranga County. One hundred and five farmers from 13 farmers' Cooperative societies were sampled from an altitude of 1300 to 1900MASL. The type of shade was characterized and it was found that in some cases trees along the hedge were observed to cast shade on coffee. In other farms, big trees in the coffee fields provided shade to the coffee below. Cherry was harvested and wet processed. Green coffee was roasted to medium roast, weighed out as whole beans (five cups of each sample). A panel of five judges evaluated the sensory attributes of the samples. Ten sensory attributes assessed for each coffee on a ten point scale: Fragrance/Aroma, flavour, aftertaste, acidity, body, balance, uniformity, clean cup, sweetness and overall perception. Generally, traditional varieties had significantly better fragrance, flavour, acidity and overall perception as rated by the panel. Altitude and shade did not seem to have any significant effect on the sensory characteristics. In terms of defects, coffee berry borer attack was significantly observed irrespective of the variety or whether coffee was under some shade or in full sun. The results are discussed in relation to possible impact of variety, altitude, and shade on coffee quality observing that shade/agro-forestry is one of the upcoming changes of coffee production systems to mitigate against climate change.