ANALISIS KADAR ETANOL PADA KOMBUCHA TEA BIAKAN SENDIRI BERDASARKAN LAMANYA WAKTU FERMENTASI

Abstract

The stages of kombucha tea fermentation involve the formation of alcohol and acetic acid because symbiotic cultures, especially fungi, break down sugar into alcohol, and the alcohol that is formed will be oxidized by the bacteria Acetobacter xylinum to acetic acid. The purpose of this study was to determine the ethanol content in kombucha tea fermentation based on the length of time of fermentation. This research is an experimental study that was tested in the Laboratory of the Department of Health Medical Laboratory Technology, Poltekkes Kemenkes Medan, from November 2022 to May 2023. The population for this study was tea of the Camellia sinensis species. The research samples included fermented kombucha tea, variant black tea and green tea which were fermented in the first, second and third weeks. The research is a quantitative qualitative study. Tests for ethanol content of home-cultured kombucha tea samples from were carried out based on the length of fermentation time in the first, second and third weeks. Black tea and green tea samples were observed for the amount of ethanol content based on the fermentation process carried out. The qualitative test was carried out using the alcohol Test-Kit Reagent method, while the quantitative test was carried out by calculating the percentage of alcohol through heating. Based on the results of the test-kit reagent, negative alcohol was found in the kombucha tea sample in the first week of fermentation, no color change after being dropped with the alcohol test-kit reagent; in the second week of fermentation, positive kombucha tea samples contained alcohol, 0.9% in black tea and 0.2% in green tea; while in the third week, an increase in ethanol levels was found, 1% in black tea and 0.7% in green tea. The highest ethanol content was found in black tea in the third week of fermentation, while the lowest level was in the fermented green tea in the second week.