Most of us just throw away egg shells after cooking eggs. Egg shells are one the best natural sources of calcium.
Wash empty eggshells in warm water until all of the egg white is removed. However, don’t remove the membrane because it contains important nutrients.
Lay broken egg shells out on paper towels and allows them to air dry thoroughly.
Now we need to grind the egg shells to into a fine powder.
You can do this in a food processor or coffee grinder, or you simply put them in a plastic bag and use a rolling pin to grind them.
Store powdered eggshells in a covered container. Store it in a dry place.