Curd , if made naturally , tastes sour .
We add acidic substance like few drops of already available curd to milk to get fresh curd .
Milk contains lactose . A bacteria called lactobacilus converts this lactose into lactic acid , thus making it sour .
The build up of lactic acid because of bacterial activity , causes the pH of milk to drop . When pH of milk becomes less than 4.6 , the particles of milk protein casein coagulate , and form curd .
Curdling is due to milk becoming sour .
We add acidic substance like few drops of already available curd to milk to get fresh curd .
Milk contains lactose . A bacteria called lactobacilus converts this lactose into lactic acid , thus making it sour .
The build up of lactic acid because of bacterial activity , causes the pH of milk to drop . When pH of milk becomes less than 4.6 , the particles of milk protein casein coagulate , and form curd .
Curdling is due to milk becoming sour .
