Anwitha Kandula
This study examines the efficiency of caffeine extraction and brewing across five internationally sourced black teas—British, Indian, Yemeni, Turkish, and Chinese—through controlled experimental trials. Caffeine was extracted using liquid-liquid extraction with dichloromethane and quantified via UV-Vis spectrophotometry to assess solubility, yield, and extraction kinetics. Indian tea showed the highest average yield (480.0 mg/min) and caffeine concentration (44.79 mg/g) during trials 2 and 3. Overall extraction rates ranged from 271.0 to 524.6 mg/min. Brewed tea pH values (4.0–5.0) suggest that mild acidity may influence caffeine solubility. High percent errors (~99%) indicate significant deviations from theoretical values, likely due to procedural variability and instrumental limitations such as solvent evaporation and calibration drift. Despite these errors, the relative ranking of caffeine concentration remained consistent across all teas, demonstrating the robustness of inter-tea comparisons. This research contributes to the field of beverage chemistry by offering a detailed methodology for analyzing caffeine content and optimizing brewing conditions.