본 연구는 쌀을 다량 첨가하여 양조한 맥주의 품질을 조사하고 쌀의 첨가 시 당화도가 떨어지는 것을 보완하기 위하여 아밀라아제를 첨가하여 품질의 변화를 분석하였다. 품질 평가를 위하여 당화액인 wort의 당도, 환원당, pH, 점도의 변화를 측정하였고, 최종 제품인 맥주의 알코올 함량, 거품안정성, 쓴맛, 색도의 변화를 측정하였다. 실험에는 쌀을 200 mesh의 쌀가루를 맥아와 쌀가루의 총량에 대하여 0, 40, 50, 60, 70%를 첨가하였다. 실험결과 쌀 함량이 증가함에 따라 wort의 당도, 환원당 및 점도는 감소하였고, pH는 증가하여 당화력이 떨어졌다. 그러나 아밀라아제 첨가에 의하여 당화력이 다시 회복되었다. 쌀 함량 증가에 따라 맥주의 알코올 함량 및 거품안정성은 감소하였고, 쓴맛과 노란색이 증가하였다. 또한 쌀 첨가량이 증가할수록 혼탁한 느낌이 강하였다.
The effects of rice adjunct on the quality attributes of beer were investigated. The results showed that the sweetness, reducing sugar content, and viscosity of beer were decreased while the pH was increased by the effect of rice content. This meant that the saccharification was not completed by the relatively reducing content of enzyme in malt, but it was recovered by the addition of α-amylase. The results showed that the additional α-amylase compensated for the reducing saccharification enzyme when the rice powder was added as adjunct. The alcohol content and the bubble stability in the beer were decreased while the bitterness and the yellowness were increased with increasing content of the rice powder. The turbidity of the beer also seemed to be increased with the rice content. Therefore, when the rice adjunct was added in beer brewing, the malt showed undesirable quality characteristics by decreasing saccharification enzyme but it could be improved by the addition of α-amylase.