A PIR Sensor-Based System for Real-Time Alcohol Monitoring and Automated Preservative Control in Fruit Wine Fermentation: Accuracy, Usability, and Adoption Assessment

Accurate and continuous measurement of alcohol concentration during fermentation is crucial for maintaining quality, ensuring safety, and ensuring regulatory compliance in fruit wine production. Traditional methods, such as manual hydrometry and sensory-based evaluation, are often limited by subjectivity, measurement variability, and a lack of real-time responsiveness. This study introduces a novel sensor-integrated system that utilizes Passive Infrared (PIR) technology to dynamically monitor alcohol levels and automate potassium sorbate dosing during the fermentation of fruit wines. The proposed system combines a repurposed PIR sensor with a hydrometer-actuated mechanical switch to estimate alcohol by volume (ABV) in real-time, achieving a validated accuracy of 94.09% when benchmarked against gas chromatography (GC) standards. Integrated control logic enables automatic preservative application aligned with ABV thresholds of 220 mg/L for 9% v/v and 50 mg/L for 14% v/v alcohol, thus ensuring microbial stability and compliance with enological standards. Experimental trials involving pineapple, mango, and grape wines demonstrated the system’s capability to capture both pre-fermentation and post-fermentation alcohol values with minimal error margins (<2%). A user experience study conducted with 20 professional winemakers and 380 broader respondents revealed high satisfaction scores across usability, observation ability, and simplicity of use, with Likert-scale ratings averaging 4.50 or higher. Statistical validation using Structural Equation Modeling (SEM) confirmed the positive influence of user experience factors on adoption intention (R² = 0.533, p < 0.001). These findings highlight the PIR-based system’s potential to modernize artisanal winemaking by offering a non-invasive, accurate, and user-friendly tool for real-time fermentation monitoring and control.