Sugar Palm Bioethanol: Fermentation Time, Turbo Yeast Dosage, and Rice-Husk-Heated Distillation for STEM Laboratory Education

Abstract

Background and Objective: Authentic STEM laboratory activities can connect renewable-energy science with measurement, engineering systems, quantitative reasoning, and sustainability. This study described sugar palm bioethanol production across fermentation-time and turbo-yeast conditions using rice-husk-heated fractional distillation and examined the workflow's prospective implications for STEM laboratory education. Methods: A 3 × 5 exploratory factorial arrangement combined 10, 20, and 30 g of turbo yeast per 11 L batch with fermentation periods of 24, 48, 72, 96, and 120 h. Each of 15 treatment combinations was processed once. Ethanol content, distillate volume, and post-fermentation pH were analyzed descriptively, and the workflow was prospectively mapped to science, technology, engineering, mathematics, and sustainability learning opportunities. Results: Ethanol content increased from 24 to 96 h at all three dosages and declined at 120 h. The highest observed value was 51% at 30 g and 96 h, with 545 mL of distillate and a qualitative pH reading of 3. The workflow supported conceptual links to fermentation science, measurement technology, biomass-heated separation, factorial data interpretation, and evidence-bounded reasoning. Conclusion: The study provides an exploratory process baseline and a defensible basis for developing a locally grounded STEM laboratory module. Because treatments were unreplicated and no students or learning outcomes were evaluated, neither statistical treatment effects nor instructional effectiveness can be claimed.