Pengembangan Sistem Kontrol pH dan Suhu Pada Fermentasi Teh Kombucha Berbasis Internet Of Things (IoT)

Abstract

This research focuses on the development of an automatic control system capable of regulating pH and temperature during the fermentation process of kombucha tea based on the Internet of Things (IoT). Kombucha is a functional beverage produced from the fermentation of sweet tea with a symbiotic culture of bacteria and yeast (SCOBY), whose quality is highly dependent on pH and temperature conditions. Instability in these parameters can lead to variations in taste, reduced nutritional value, and even risks of contamination. Therefore, a control system that can monitor and maintain fermentation stability in real-time is required. In this study, a prototype system was designed using the ESP32 microcontroller integrated with the E-201C pH sensor kit and the DS18B20 digital temperature sensor. The measurement data are processed and displayed through the Blynk application, allowing users to monitor conditions remotely. In addition, actuators such as a heater, exhaust fan, servo, relay, and solenoid valve are automatically controlled to maintain the fermentation parameters within the optimal range. The experimental results showed that the system successfully maintained the pH in the range of 2.5–4.2 and the temperature between 25–30 °C, which are the ideal conditions for kombucha fermentation. Sensor accuracy tests indicated an average error tolerance of less than 5%, with the pH sensor showing a precision of 0.69% and the DS18B20 temperature sensor achieving 97.54% accuracy. With this performance, the developed system proved effective in improving the consistency of kombucha quality and demonstrated the potential of IoT-based technology in supporting the fermentation process of functional beverages.