Characteristics of blueberry added makgeolli

Blueberry makgeolli (rice wine) was made with rice and various quantities of blueberries and the fermentation characteristics of the makgeolli were studied during the fermentation process. pH was the highest (6.6) at the beginning of fermentation and decreased as the ratio of blueberries increased. The pH fell quickly until the 2nd day and then remained constant until the 7th day of fermentation. Total acidity increased significantly until the 4th day of fermentation and then remained constant until the 7th day. Sugar contents (°Brix) and reducing sugar contents reached a max. after 2 days of fermentation and then gradually decreased until the 7th day. Alcohol content of the control (0% blueberries) increased continuously until the 7th day of fermentation when it was at 13.4%. Alcohol content of 20% blueberry makgeolli reached a max. on the 4th day of fermentation and then slowly decreased to 10.2% at the 7th day. Total viable bacterial cell counts and yeast cell counts showed max. values at the 3rd day of fermentation. In sensory evaluation, the colour of the control sample was the most favored by the panelists, whereas the 20% blueberry sample was the least favoured. There were no significant differences in flavour and taste, but overall preference was high for makgeolli with <10% of blueberries.