Abstract:Boza is a kind of fermented beverage with ethnic characteristics，which is made by using grain as raw material through traditional fermentation.In this experiment，rice flour，millet flour and maize flour were used as raw materials，and yeast and lactic acid bacteria were used as fermentation agents for fermentation production.The pH value，total acid，total sugar，ash，protein，solid alcohol content and viscosity change of the boza under different fermentation times were investigated.Finally，the optimal fermentation time was selected based on the sensory evaluation.The experimental results showed that the fermentation taste was best at 48 h，and the characteristic of fermented wine had more flavor.Under this condition，the pH value was 4.0，the total acid content was 2.8 g/L，and the total sugar content was 3.4 g/L.The ash content was 2.0 g/L.The solid content was 2.5%，the alcohol content was 1% vol，and the viscosity was 39 cP.