Microorganism growth profiles during fermentation of Gayo Arabica wine coffee

Abstract

Coffee is a non-alcoholic beverage that is consumed globally due to its specific flavour and functional properties. Nowadays coffee is diversified based on its coffee varieties, brewing methods, and bean processing techniques. Wine coffee is a commercial name for fermented coffee, a new coffee diversification product. Wine coffee is produced by fermenting coffee cherries for 30 to 60 days. As a new product, the process is not well studied. This research aims to explore the microorganisms’ activity and its profile growth during 30 days of fermentation. The documentation of pH and temperature, and microbial sampling during coffee cherry fermentation were conducted seven times, started at 0 days; 2 days; 4 days; 6 days; 8 days; 10 days; 12 days; 14 days; 16 days; 20 and 30 days. The results showed that pH decreases and temperature increases during fermentation. pH started from 5.0 and down to 3.9 when fermentation is terminated after 30 days, whilst the temperature slightly changes from 25°C to 30°C. The microorganism’s population shows the presence of yeast, lactic acid (LAB) and acetic acid bacteria (AAB) in wine coffee production. The yeast population increases in the mid fermentation as the cherries are damaged and provide suitable nutrition for the yeast. LAB also co-exists at a similar stage. Further research should be done, especially to understand the interaction mechanism between yeast and yeast, yeast and LAB, and yeast and AAB.