Sour milk can be bought in stores, but you should check its ingredients: milk and lactic acid bacteria cultures. However, ...

I therefore concluded that electricity has no direct agency in turning sweet into sour milk during a thunder ... to the development of lactic acid in the milk. It was this acid which, in the ...

when kefir grains are added to milk and left for 24 hours, the microorganisms multiply and this starts the fermentation process, turning the lactose into lactic acid. Bang: you've got DIY kefir.

These days it is commonly made commercially; a bacterial culture being added to skimmed or whole milk. Buttermilk has a slightly sour taste and the lactic acid in combination with baking soda or ...