Why Does Greek Yogurt Taste Sour?
Greek yogurt tastes sour because of the lactic acid produced during the fermentation process. The milk used to make Greek yogurt is first heated and then mixed with live bacterial cultures, such as Lactobacillus bulgaricus and Streptococcus thermophilus. These bacteria consume the lactose (milk sugar) in the milk and convert it into lactic acid, which gives the yogurt its characteristic tangy and slightly sour taste. Additionally, the longer the fermentation process, the sourer the yogurt tastes.