The difference between white flour and whole-wheat flour is one ingredient: wheat germ. That's what gives it the distinct off-white color and nutty taste. But because the wheat germ has natural oils in it, whole-wheat flour spoils much more quickly than white flour. To extend its lifespan, store whole-wheat flour in the freezer. It keeps the oils stable and will add months to the shelf life. Be sure to keep the flour in an airtight container to keep it smelling and tasting fresh.