The effect of fermentation time of aren palm sap (Arenga pinnta) on the amount of Saccharomyces cerevisiae and alcohol content

Background and Aim: Palm sap is a sweet liquid obtained from tapping immature palm flower bunches and is highly susceptible to natural fermentation due to the presence of Saccharomyces cerevisiae. The fermentation process plays a crucial role in determining vinegar quality, particularly alcohol production. This study aimed to evaluate the effect of fermentation time on the population of S. cerevisiae and alcohol content in palm sap. Materials and Methods: This study employed a laboratory experimental method using a completely randomized design. Palm sap was fermented for different durations (0, 12, 24, 48, 72, 96, and 120 hours). Alcohol content was measured using an alcoholmeter, while the population of S. cerevisiae was analysed during the fermentation process. Results: The results showed that alcohol content increased with fermentation time, reaching 0% at 0 hours, 1% at 12 hours, 2% at 24 hours, 4% at 48 hours, and a maximum of 7% at 72 hours, before decreasing to 5% at 96 hours and 3% at 120 hours. A significant increase in the population of S. cerevisiae was observed up to 72 hours of fermentation, followed by a significant decline at 120 hours. The highest alcohol content coincided with the peak population of S. cerevisiae. Conclusion: Fermentation time significantly influences the population of S. cerevisiae and alcohol production in palm sap. The optimal fermentation duration was 72 hours, which produced the highest alcohol content and S. cerevisiae population. These findings indicate a positive association between yeast population and alcohol production during palm sap fermentation.