Towards consistency of rice wine quality through standardized bubod

Tapuy (rice wine) is a traditional beverage used during ceremonial occasions in the northern part of the Philippines. It is made by inoculating starter culture (bubod) to steamed rice to allow saccharification and fermentation to occur. Since the kind and amount of microorganisms present in bubod are unknown, inconsistent rice wine quality is often observed. To ensure the production of high quality rice wine with long shelf-life, the traditional bubod must be standardized through hygienic method of preparation and proper microbial strain selection. In this study, various combinations of pure mold (Rhizophus oryzae) and yeasts (Saccharomyces cerevisae and Saccharomycopsis fibuligera) were used in preparing wine using varying inoculation method (simultaneous and sequential) and pre-fermentation time (24 and 48 hours). Evaluation of wine quality considered yield, physicochemical properties, and sensory profile. Rice wine from the 70:15:15 combination of R.oryzae; S.cerevisiae; S.fibuligera obtained high scores for overall acceptability and intensity of sweetness with least off-order. Wine yield was higher in the set-up pre-fermented for 24 hours and microorganisms inoculated simultaneously than in the setup pre-fermented for 48 hours and micro-organisms inoculated sequentially. The 24-hour pre-fermented setup obtained wine with higher alcohol content (11.57 to 13.56%), lower total soluble sugars (14.65 to 23.45 deg brix), higher pH(3.82 to 3.97), more intense alcoholic taste, and lower intensity of sweetness than in the 48-hour pre-fermented setup. Therefore, this study revealed that a combination of 70:15:15 R.oryzae: S.cerevisiae: S.fibuligera, inoculated to cooked rice simultaneously and pre-fermented for 24 hours produced the best wine with good reproducibility. Development of standardized bubod with known identity and amount of microorganisms is a big step towards achieving excellent wine quality and long shelf-life, with reliable consistency.