PURPOSE: To obtain a yogurt-like food having excellent taste and flavor, without addition of sugars, by fermenting soya milk or processed soya milk with Streptococcus sojalactis.

CONSTITUTION: A lactified soya milk is prepared by fermenting soya milk or processed soya milk with Streptococcus sojalactis (FERM-P No.6926, a novel strain obtained by culturing a lactobacillus strain separated from a processed bean food, in soya milk). The first characteristic feature of the strain is that it can be cultrued in a medium composed solely of soya milk and produce lactic acid, and the second feature thereof is that it gives a solid product having excellent taste and flavor by the fermentation of soya milk. The characteristic grassy smell of soybean can be eliminated, and the unique flavor components of fermented milk can be produced by this process.