Sistem Pemantauan pH dan Kadar Alkohol Serta Pengendalian Suhu Pada Fermentasi Kombucha Menggunakan Metode Logika Fuzzy

Riffan Sudira; Nini Firmawati; Wildian Wildian; Rahmat Rasyid

doi:10.25077/jfu.15.6.562-569.2026

Authors

Riffan Sudira Departemen Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Andalas
Nini Firmawati Departemen Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Andalas
Wildian Wildian Departemen Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Andalas
Rahmat Rasyid Departemen Fisika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Andalas

DOI:

https://doi.org/10.25077/jfu.15.6.562-569.2026

Keywords:

Alcohol, fuzzy logic, Internet of Things, kombucha, pH

Abstract

The kombucha fermentation process is influenced by temperature, pH, and alcohol content; therefore, proper monitoring and control are required to maintain product quality and ensure that the alcohol level remains below the halal limit of 0.5%. This study developed an Internet of Things–based system capable of monitoring pH and alcohol content as well as automatically controlling the fermentation chamber temperature using fuzzy logic. The system employs an ESP32 microcontroller integrated with DS18B20, pH-E4502C, and MQ-3 sensors, and controls a heating element and DC fan through Pulse Width Modulation (PWM) signals based on fuzzy evaluation of the actual temperature and its deviation from the 29 °C setpoint. The data are displayed on an LCD, transmitted in real time to the Blynk application, and stored in Google Sheets. Experimental results showed that the system was able to maintain the fermentation temperature close to the setpoint with good stability. The DS18B20 sensor achieved an average error of 0.41%, while the MQ-3 and pH-E4502C sensors showed high correlation coefficients with R² values of 0.9992 and 0.9987, respectively. Monitoring results during 111 hours of fermentation showed a final pH value of 3.37 and an alcohol content of 0.48%, meeting quality standards and halal requirements. Therefore, the developed system is effective for automatically and accurately monitoring and controlling the kombucha fermentation process.

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