Save eggshells from organic, free-range eggs. Immediately rinse shells under warm running water, removing all egg white residue and membrane. Scrub gently with a soft brush to remove stubborn membrane pieces.

Pat shells completely dry with paper towels before storage.

Preheat your oven to 200°F (93°C). Arrange clean, dry eggshells on a baking sheet lined with parchment paper.

Bake for 10-15 minutes until shells become brittle and slightly yellowed. Allow shells to cool completely before handling.

Transfer cooled shells to a clean coffee grinder or high-powered blender. Pulse in short bursts to prevent overheating.

Continue grinding until you achieve a fine powder consistency similar to flour, ensuring no gritty particles or sharp edges remain.

Test quality by rubbing a pinch between your fingers - it should feel smooth without rough texture.

Store finished eggshell powder in an airtight glass jar in a cool, dry location. Label with preparation date.