Of course, nuts lasts for a shorter period of time if they are not stored properly. Opened packages will last for a shorter time, again depending on the variety. But remember that nuts, unlike a lot of other proteins , usually have a best by date and not an expiration date. Because of this distinction, you may safely use nuts to compliment your favorite meals even after the best by date has lapsed. As a rule, nuts that are purchased in their shell will last for a shorter period of time than those which have been shelled. This has a lot to do with the packaging and is true as long as the package is unopened. Once the package has been opened, nuts with the shells intact will generally last for a longer period of time than those which were already shelled.