Adding Eggshells In Coffee – A Good or Bad Idea?

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Coffee and eggs are two staples of many breakfast tables. Usually, we eat these two items, but what if combining them could create a delicious product? Rather than sticking with the usual cream and sugar, many coffee drinkers are adding eggshells to their coffee. 

Read on to learn why people put eggshells in coffee and how you can try this technique yourself. 

Why Would People Add Eggshells To Coffee?

There are several reasons someone may use egg shells in coffee. Many people choose this addition because it changes the flavor of the coffee, and others add eggshells. After all, it changes the way coffee grounds act. 

Eggshells make coffee less bitter and acidic

Coffee is naturally quite acidic. Depending on the roast of the bean, the water temperature, and the steep length, coffee may be more acidic. That acidity can increase the bitter flavor of the coffee. 

Those drinkers who do not love bitterness find ways to get a smoother sip. Eggshells are an increasingly popular way to mellow out coffee. Eggshells primarily consist of calcium carbonate, which is highly alkaline. This alkalinity neutralizes the acidity of coffee, leading to a less bitter cup of coffee. Remember to use shells from uncooked eggs, you don’t want sulfurous flavor in your coffee.

Cowboy coffee and eggshells

While coffee can be bitter for anyone, it is especially prone to this issue when cooked over a campfire. The heat from such a fire is difficult to control. When cowboys cook their coffee over a fire, they cook coffee directly in boiling water, leading to a high likelihood of bitterness. Cowboys found that adding eggshells to the mixture reduced bitterness. 

Adding eggshells to your ground coffee is also a way to keep grounds from rising to the surface. This benefit is only relevant for brew styles involving loose grounds, such as in cowboy coffee.  


How To Use Eggshells In Your Coffee?

You can use eggshells in any brewing method for coffee. However, your approach will vary slightly depending on how you brew your cup of joe. 

Adding Eggshells In Drip Coffee

Drip coffee is a drink made from dripping hot water through coffee grounds. For this description, drip coffee will include coffee made from a coffee maker and pour-over coffee. It is easy to add eggshells to this type of coffee.  

Step 1: Crack eggs

Unless you also want to add an egg’s innards to your coffee, you need to crack it to remove the shell. Save the egg whites and yolks for your breakfast.

How many eggshells to use depends on how much coffee you are brewing. In general, you will need one egg per small pot of coffee (four cups or so) or two eggs for a big pot. If possible, try to crack the eggs cleanly so you can easily keep track of all parts of the shells. 

Step 2: Clean shells

Cleaning your shells is essential to good results while using eggshells in your coffee. Gently rinse the shells under hot water until the shells seem clean. 

Step 3: Crush shells

Choose a way to crush the shells: in your hand, with a mortar and pestle, or with a rolling pin. The crushed shell pieces should be about the same size as your coffee grounds. 

Step 4: Measure coffee into the machine

You will likely be familiar with this step. All you need to do is add coffee to your machine as you usually do. Add the eggshells on top of your measured coffee. 

Step 5: Brew!

All you need to do here is brew your coffee as you normally would. 

Step 6: Discard coffee grounds and eggshells

A fun bit about making coffee in this way is both used coffee grounds and eggshells are compostable.  

Step 7: Pour your cup

You can finally try your coffee to see if the eggshells make a difference. Look out for any eggshells in the resultant coffee. 

Adding Eggshells In Cowboy Coffee (Campfire coffee)

Making campfire coffee is different than other types. Unlike other modern coffee pots, coffee grounds float freely in hot water instead of being separated by a barrier. Adding eggshells in the coffee pot helps settle down the grounds and results in a cleaner cup of coffee.

Step 1: Follow the first three steps of the drip coffee instructions

Preparing the eggshells is usually the same process, no matter which type of coffee you make. When taking these steps while camping, ensure you are thoughtful of the requirements of the nature you are in and discard any components properly.  

Step 2: Start a fire

Nothing is worse than setting out to make a cup of coffee and realizing you do not have the necessary heat. Fire or a camp stove is essential to making coffee while camping. 

Step 3:Add one quart water and a pinch of salt to a pot and heat

Adding a bit of salt to your coffee will bring out some flavor. Salt in coffee also helps balance acidity and bitterness. Heating your water properly will help to bring out the flavor of the coffee grounds and the alkalinity of the eggshells. 

Step 4: Add coffee grounds and eggshells to warm water and stir

After ensuring the water is warm, add coffee and crushed eggshells. Stir to help the water permeate all coffee grounds and shells. 

Step 5: Bring water to a boil

Bring the water to a boil for two or three minutes. Doing this will help the full flavor develop. Steeping for longer may require adding eggshells at the start. 

Step 6: Remove from the heat

When you remove the coffee from the heat, let the mixture sit for a few minutes to help the grounds sink to the bottom of the pot. 

Step 7: Serve

Pour the coffee into cups and enjoy your cowboy coffee. 

Adding Eggshells In French Press

Finally, you can add eggshells to your French press coffee. Here’s the step-by-step process. 

Step 1: Follow the steps to process the eggshells

Since a French press requires coarser ground coffee, you may also want to leave your shells slightly coarser. 

Step 2: Grind coffee coarsely

As mentioned, you should ensure the coffee you use in your French press is coarsely ground because a coarse grind makes it more difficult for the grounds to escape the straining step of the process. 

Step 3: Boil water

The water you use in this process should be hot, but not too hot. If needed, let the water cool for a few minutes. Overly hot water will increase bitterness. As a result, you may want to use more eggshells in a French press than you would with drip coffee. 

Step 4: Add grounds, shells, and hot water to your French press

Start by adding your eggshells and coffee grounds and pour the water over the mixture. 

Step 5: Steep 

Let the mixture steep for about four minutes. Steep for longer or shorter, depending on your tastes. 

Step 6: Press the coffee

Take the plunger and press it down to put all the grounds and shells at the bottom. 

Step 7: Serve 

Pour the coffee from the French press into a mug and enjoy!

Useful Tips For Making Eggshell Coffee

Here are a few tips to make your eggshell coffee more successful. 


Don’t use eggshells from boiled eggs

Using shells from boiled eggs can make your coffee taste bad since eggs release sulfur compounds after cooking. Therefore, you should only use shells from raw eggs. You can always cook the egg later. 

Use fresh eggs

Fresh eggshells will yield the best results. Older eggs or saved shells can be less effective when mellowing the flavor of the coffee. 

Use pasteurized eggs

While brewing coffee with eggshells, it is still a good idea to only use pasteurized shells when putting them in coffee. 

Final Thought

If you love coffee, wait until you see what adding eggshells can do to your morning cup. Trying this method could help someone who dislikes coffee embrace the beverage. Whether you make drip, cowboy, or French press coffee, this ingredient can cut the bitterness. 

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Chris Clark

Chris Clark is the co-founder and chief content editor of With a passion for all things java, Chris has been a coffee blogger for the past 3 years and shares his expertise in coffee brewing with the readers. He's a hands-on expert, loves testing coffee equipment, and has written most of the in-depth reviews featured on the site. When he's not whipping up delicious drinks or experimenting with the latest coffee gadgets, Chris is exploring the local cafe.