The effect of starter concentration and fermentation time on the quality of kombucha cascara robusta (<i>Coffea canephora</i>)

Abstract Cascara was never optimally used and was often left on the ground to be used as fertilizer, some research has shown that cascara contains several nutritional benefits that still have the opportunity to produce food that is both healthy and sustainable for supporting food security. In this research, the effect of different starter concentration additions as well as fermentation time on Kombucha Cascara Robusta quality was investigated. Research on kombucha made from cascara is still very limited and is generally made from arabica variety, therefore the robusta variety was chosen with different treatment from existing research. Cascara was obtained by drying the coffee skin, then brewed in hot water as tea. Cascara tea would then be fermented (W) for 6, 9, 12, and 15 days into kombucha with starter (S) 5%, 10%, 15%, and 20% concentration kombucha starter. The quality parameter consisting of antioxidant activity (Ic 50 ), total acid, pH, total plate count, and color (°Hue values) was observed. The results show that the higher the starter concentration and fermentation time, the greater the total acidity. S 1 W 1 treament give 0.3964% in total acidity while S 1 W 2 give 0.4941% total acidity.