Pecans kept at room temperature in a sealed air-tight container will last up to 45 days. Refrigerate your pecans to extend the freshness 6-9 months. When frozen in an air-tight container, pecans can last up to 2 years. Pecans can be thawed and re-frozen multiple times. Store alone. Pecans have a high oil content and have a tendency to absorb odors when stored with other items.