Some low-moisture foods such as dried apples can be safe to eat even years after their expiration date, if properly stored, food chemists say. They verified this in a tasting experiment of 28-year-old rolled oats. Heat, moisture and light can degrade food's nutritional value. The next time you find forgotten food in the pantry, don't just toss it. Keeping food past its expiration date may not seem like a good idea, but certain foods last a lot longer than you think -- years longer.