Can packaged yogurt ferment before the expiration date?

Yes, packaged yogurt can ferment before the expiration date. Fermentation is a natural process caused by bacteria that convert the lactose in milk into lactic acid. This process gives yogurt its characteristic tangy flavor and thick texture. While packaged yogurt is typically pasteurized to kill harmful bacteria, some beneficial bacteria may still be present and can cause the yogurt to ferment further over time. Factors such as storage temperature, exposure to air, and the type of bacteria present can affect how quickly yogurt will ferment. To ensure the best quality and safety, it's important to follow the storage instructions on the yogurt package and consume it before the expiration date.