Place the raw cumin seeds in a spice grinder. Grind for 30-40 seconds, stopping and shaking the grinder as needed to help evenly distribute the spices. The seeds will grind to a fine, textured powder.
Transfer the ground cumin (use a spice funnel to make this easier) to a spice jar or a small airtight container. Store for up to 6 months. (See Storage Tips.)
Note 1: In most cases, I use raw cumin seeds to make cumin powder. See post for tips on when it's best to toast and how to toast before grinding.Note 2: The cumin powder will remain same weight after grinding but will be less in volume (cups). (3/4 cup cumin seeds = ~2/3 cup cumin powder).