Lactic acid bacteria were used to ferment soy milk and make soy yogurt. L. bulgaricus produced the most acid, while S. cremoris produced the least. Soy yogurt flavor was not as good as milk yogurt, but L. bulgaricus-made soy yogurt tasted the best. People preferred fermented soy milk over unfermented. Fermentation reduced a bad smell in soy milk and added a buttery taste not in unfermented soy milk.