Eggs are one of my favorite foods. They accompany my coffee or tea almost every morning. However, reusing the eggshells for my coffee isn’t something I’d ever consider doing. Maybe you’ve heard of using eggshells and wanted to look into it. Let’s take a look at the most popular reasons for using them in coffee.

The eggshells are said to be used for two different purposes. The first is said to reduce the bitterness of the coffee. The second is to remove suspended coffee grounds. Let’s explore these methods.

Reasons for Using Eggshells in Coffee

Egg shells are almost entirely calcium carbonate, an alkaline material that can absorb the acid. They also consist of magnesium carbonate, calcium phosphate, and other organic matter. The only possible benefit of adding them to the grind is to raise the coffee’s pH level. Coffee is somewhat acidic but almost neutral so it’s unclear how any change in the pH would be perceived in the mouth.

ph scale

A better alternative that doesn’t have you removing residual egg whites and yolks: brewing a better cup of coffee so that it’s not acidic. Pretty simple.

People also use egg shells to settle suspended coffee grounds. With that said, I’m not entirely sure how added varying sizes of calcium carbonate can settle coffee grounds.

How to Use Eggshells in Coffee

Adding eggshells to coffee isn’t that common anymore. While I’m not a fan of adding them to my coffee, you may be curious how to do it.

  1. Note that you can’t use egg shells from hard boiled eggs. When eggs are hard boiled, they release a sulfur compound that can permeate the coffee grounds. So, assuming you made some eggs for breakfast. Set the eggshells aside. Typically 2 eggs is more than enough.
  2. Wash the egg shells to remove any egg whites or yolk residue.
  3. Crush the egg shells into a more course consistency.
  4. Add the eggshells to the coffee grounds.
  5. Brew your cowboy coffee.


These days, due to how much control you have over your coffee there isn’t a need for additional alkaloids to balance acid levels. Coffee itself is already fairly neutral and rates around a 5 on the pH scale. This is around the same level of acidity as a banana. Let that sink in.

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Clayton Dylan

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