If you plan to eat them within the week, simply put them in an airtight container in the refrigerator. For longer storage, wrap bars individually (or better yet, vacuum-seal them) and freeze them. Sealed breakfast bars will last up to four months in the freezer. Thaw frozen bars to room temperature whenever you want one. They’re delicious cold, but for a warm breakfast on the go, ten seconds in the microwave makes them even better.