Yogurt can be eaten past the expiration date. An unopened container of regular plain yogurt can last two to three weeks past the expiration date. But once opened, the yogurt is only good for one week past the expiration date.
Different varieties of yogurts stay fresh for varying amounts of time. For example, an unopened drinkable yogurt or yogurt with fruit has a shorter lifespan of seven to ten days. Greek yogurt and reduced fat yogurt are good for one to two weeks past the expiration date. If there is an excessive amount of liquid at the top of the yogurt or a curdling texture near the bottom of the yogurt, the yogurt is spoiling and should be thrown away.