Yes! It will help you brew the smoothest (least bitter) coffee! I know, it sounds strange. But try it at least once before you write it off. During the depression era this was a common practice used mainly with cheap, bitter, or over extracted coffee. It also helps to settle the grounds.
First you need to hard boil the eggs ( great time to try it is just before Easter - generally a few eggshells break and can't be decorated - PERFECT! )
Peel the eggs (you can use the eggs for a small egg salad, devil them, or dash with salt and enjoy)
Then bake the shells at 350 for approximately 10 minutes. Crush them up and put them in a small bowl or Ziploc bag. Mix in the grounds and use the mixture in your drip coffee machine as normal.
Later on after it has cooled you can put the mixture back into the Ziploc bag for safe keeping until the next time you go out into the garden. It is GREAT for flowers too!!!!
( Also makes a great gift for a friend that has a garden.)
Seriously, you have NEVER tasted coffee like this before if you haven't tried eggshells yet. Feel free to keep this hint our little secret and your friends will think that you simply have a magic touch!