Roasting cumin seeds before long-term storage is not necessary and can actually reduce their shelf life and flavor. Store them raw in an airtight container in a cool, dark place.
Cumin seeds contain volatile oils that give them their distinctive aroma and flavor. Roasting these seeds before storing them long-term can cause these oils to dissipate more quickly, leading to a loss of flavor over time. While roasting enhances the flavor of cumin for immediate use in a recipe, it's best to store them raw to preserve their potency for extended periods. To ensure freshness, purchase whole cumin seeds rather than ground cumin, as whole seeds retain their flavor longer. Store the seeds in an airtight container, away from direct sunlight, heat, and moisture. A cool, dark pantry or cupboard is an ideal location. Properly stored raw cumin seeds can maintain their quality for up to a year or even longer.
Only roast the amount of cumin seeds you plan to use within a few days. This way, you get the best flavor from freshly roasted seeds without compromising the quality of your long-term storage supply.