<![CDATA[Kombucha is a fermented tea beverage produced using a Symbiotic Culture of Bacteria and Yeast (SCOBY) and is recognized as a functional drink due to bioactive compounds with antioxidant properties. The incorporation of traditional Indonesian herbal ingredients, such as beras kencur, offers the potential to enhance its functional value. This study aimed to evaluate the effect of different fermentation periods on the chemical characteristics of beras kencur kombucha and determine the optimum fermentation period. A Completely Randomized Design (CRD) was used with four fermentation periods (0, 7, 14, and 21 days), each replicated six times. The observed parameters included pH, total titratable acidity, vitamin C content, total phenolic content, total flavonoid content, and antioxidant activity. Data were analyzed using one-way analysis of variance (ANOVA), followed by Duncan’s Multiple Range Test (DMRT) at a 5% significance level. Fermentation period significantly affected pH, total titratable acidity, vitamin C content, total phenolic content, and total flavonoid content (p < 0.05), but had no significant effect on antioxidant activity (p > 0.05). Longer fermentation decreased pH and vitamin C content, while increasing total titratable acidity, total phenolic and flavonoid contents, and antioxidant activity. The 21-day fermentation period produced the most desirable chemical characteristics, including a pH of 3.22, a total titratable acidity of 2.78%, an antioxidant activity of 44.29%, the highest total phenolic and flavonoid contents, and the lowest vitamin C content (6.97 mL/L). Therefore, a 21-day fermentation period was identified as the optimum treatment for producing beras kencur kombucha with enhanced functional properties.]]>
