The more fermented strains in yogurt, the better. Although a variety of "probiotics" are added to some starter cultures, there is a competitive relationship between different strains, and most probiotics can't stand it during fermentation and die.

Secondly, simultaneous fermentation of multiple strains will not make yogurt "more balanced in nutrition", and its influence on yogurt flavor is extremely limited. At present, lactobacillus bulgaricus and streptococcus thermophilus are commonly used yogurt strains, so it is enough to choose those with these two starter cultures.

Extended data:

Yogurt is a typical fermented food. Because of the existence of dominant bacteria (lactic acid bacteria), other microorganisms are difficult to grow and reproduce, so it is quite safe. However, if lactic acid bacteria are mixed with miscellaneous bacteria in the early stage of fermentation, it may lead to the failure of yogurt fermentation and even food safety problems.

The raw materials for making yogurt can be pasteurized milk and normal temperature milk, both of which are sterilized and generally have no potential safety hazards. Even if you choose the raw materials for blending milk powder, there will generally be no problem. Containers are the most easily mixed with miscellaneous bacteria in homemade yogurt. It is best to use special containers for homemade yogurt, and it is best to sterilize at high temperature before each use, which can basically avoid the failure of yogurt fermentation.

People's Daily Online-Homemade yogurt has potential safety hazards, and container hygiene cannot be ignored.