The quality and flavour effects of robusta coffee cultivated at various altitudes in Aceh Tengah District - Gayo Highlands were investigated

Abstract Gayo Highland (GH) is known for its arabica GH also planted robusta in lower altitude areas, but its quality is rarely reported. In Indonesia, robusta is mostly planted in Lampung and Java and thus is well-examined and reported. This study explores the quality of the Gayo-robusta-picked coffee cherries and its green bean and the effect of post-harvest practices farmers apply towards the quality of Gayo robusta. This research used RBF Design with two factors and four repetitions. Factor A is altitude levels, which are 600-800 m.a.s.l, 801-1.000 m.a.s.l and 1.001-1.200 m.a.s.l. Factor B is post-harvest practices, which have two levels with and without post-harvest practices. The result shows that 800-1.000 m.a.s.l altitude showed better quality of red cherries (75.25% ± 3.30) as the black and green cherries percentages are lower than other levels. As the altitude increases, green beans tend to have higher moisture, defect value, and bigger size. The average moisture of the green bean was 12.44%, the defect value was 12.51%, and the green bean size that passed the 6.5 mm sieve was 86.84%. For the cupping test, the average score was 67.33. The best treatment was robusta was planted on 600-800 m.a.s.l and, with post-harvest practices, had a cup test value of 80.25 and was considered a quality of fine Robusta.