Yes, you can store millet flour in the refrigerator to help prevent clumping and extend its shelf life. Ensure it's in an airtight container.
Millet flour, like other whole grain flours, contains natural oils that can go rancid over time, especially when exposed to heat, light, and air. Refrigeration slows down this process, preserving the flour's freshness and preventing it from developing an off flavor. Clumping can occur due to moisture absorption. Storing millet flour in an airtight container in the refrigerator minimizes moisture exposure, thus reducing the likelihood of clumping. To store it properly, transfer the millet flour from its original packaging into an airtight container. A plastic container with a tight-fitting lid or a resealable freezer bag works well. Before using refrigerated millet flour, allow it to come to room temperature to prevent condensation from forming, which could lead to clumping during baking.
If you live in a humid climate, consider adding a food-safe desiccant packet to the container with your millet flour to absorb any excess moisture and further prevent clumping.