Abstract: Using expanded beans and multi-strains to produce soybean paste, the optimum conditions for preparation of koji and fermentation through single factor and orthogonal test were obtained. The results were that Aspergillus oryzae 3.951 and Aspergillus niger 3.350 could make the koji respectively and the ferment mixedratio was 8∶2. Taking low mash density fermentation and adding 5% Zygosaccharomyces rouxii As 2.371 to ferment mash, the paste could be produced after 15～20 days fermentation with stable and good flavor. This fermentation time was sharply shorter than that of traditional technique, The new technology could increase material yield and equipment utilization rate.

Key words: Expanded bean , Multi-strains , Thin soybean paste , Fermentation