To maintain the freshness of nuts, it is generally better to purchase them in smaller quantities, ensuring they are consumed while still fresh. However, there are several steps that you can take to preserve the freshness of already opened nuts. These steps include storing the nuts in a cool, dry, and dark place, ideally in airtight containers. Additionally, nuts should keep for even longer if stored in a refrigerator. The label of the nut product should also provide guidance on the recommended storage time. A quick smell and taste test should also help to determine how fresh the nuts are.