Things You'll Need
- Food processor, blender or coffee grinder
- Cookie sheet or baking pan
Instructions
Wash eggshells out after you have emptied them, then save them for no more than a week. You will not want to use eggshells that you have stored for longer than a week.
Heat the oven to 350 degrees Fahrenheit.
Place the shells on a cookie sheet or baking pan and put them in the oven for eight to 10 minutes. This will make them brittle and ready to grind.
Grind the shells in the food processor, blender or coffee grinder until they turn to a fine powder.
Place the powder in a jar and keep it refrigerated for up to a year.