It is still unclear in the literature whether it is possible to use brain wave power to measure a subject's personal preference for different beverages. We conducted two experiments to investigate the relations between subjective evaluation of a beverage and physiological responses by measuring the activities of the central nervous system before and after the intake of different kinds of beverage. First, we took measurements when subjects ingested water of different temperatures and studied the differences in results. We then performed a similar experiment using different beverage samples at the same temperature, identified by the subject as his “favorite” or “least favorite” from among ten commercially supplied soft drinks. In each trial, subjects consumed the favorite and least-favorite beverage along with Kuding tea, a bitter-tasting drink used in Chinese medicine. Our results found that beverages might affect mood in relaxation and mental task performance, and that these changes showed correlations with frontal EEG alpha band activities.