The process is different: the original yogurt belongs to "fermentation before packaging", that is, a large jar of milk is fermented into yogurt, then stirred evenly and packaged into small bottles. Old yogurt belongs to "packaging before fermentation". First, milk is packaged into small bottles, and then lactic acid bacteria are added for fermentation. It looks like a gel without stirring.

Taste difference: the fermentation time and taste of original yogurt and old yogurt are different. The original yogurt is more sour and smooth, and the old yogurt is more sour and thick.