How to distinguish spoiled milk from fermented milk like kefir?
Context Milk that has gone bad and fermented milk (kefir) both involve bacterial growth. However, there are key differences to understand. Simple Answer Spoiled milk has harmful bacteria that make you sick, while kefir has beneficial bacteria that are good for you. Spoiled milk smells sour and tastes bitter, while kefir has a slightly sour but pleasant flavor. Spoiled milk has a thick, lumpy texture, while kefir is smooth and drinkable. Spoiled milk can cause food poisoning, while kefir is a healthy probiotic. Spoiled milk should be discarded, while kefir can be consumed or used in cooking. Detailed Answer When milk spoils, it undergoes a process called lactic acid fermentation. This is caused by bacteria that convert the lactose in milk into lactic acid. This process gives spoiled milk its characteristic sour smell and taste. Lactic acid fermentation is also what gives kefir its slightly sour flavor. However, kefir is fermented by a different type of bacteria than spoiled milk. These...