To enhance the growth of Lactobacillus bulgaricus and minimize the growth of Streptococcus thermophilus relative to each other. A method for producing fermented milk, said method comprising: a starter addition step in which a lactic acid bacteria starter containing Lactobacillus bulgaricus and Streptococcus thermophiles is added to a starting milk in order to obtain a fermented milk base material an acidity adjustment step in which the acidity of the fermented milk base material is adjusted to 0.2% or higher and a fermentation step in which the fermented milk base material is fermented after the acidity adjustment step in order to obtain fermented milk. In this way, it is possible to enhance the relative growth of Lactobacillus bulgaricus without the use of additives such as lactic acid bacteria growth-promoting agents or the like, and it is thus possible to produce fermented milk that does not have an unpleasant taste and that contains a large amount of polysaccharides derived from Lactobacillus bulgaricus.相對地促進保加利亞菌的繁殖,且相對地抑制嗜熱性鏈球菌的繁殖。關於本發明之酸乳的製造方法包含:在原料乳中添加含有保加利亞菌及嗜熱性鏈球菌的乳酸菌菌元而得到酸乳基材的菌元添加步驟;將酸乳基材的酸度調整至0.2%以上之酸度調整步驟;以及使酸度調整步驟後的酸乳基材發酵而得到酸乳的發酵步驟。藉此可不使用乳酸菌的繁殖促進劑等添加物,就能夠相對地促進保加利亞菌的繁殖,因而能夠製造含大量源自保加利亞菌之多醣體而沒有雜味的酸乳。S1‧‧‧原料乳調製步驟S2‧‧‧殺菌步驟S3‧‧‧冷卻步驟S4‧‧‧菌元添加步驟S5‧‧‧酸度調整步驟S6‧‧‧加溫步驟S7‧‧‧發酵步驟S8‧‧‧再冷卻步驟S9‧‧‧厭氣步驟
