The Accidental Scientist: Science of Cooking Exploratorium
Candy Bread Eggs Pickles Meat Seasoning

activity: Making Naked Eggs
A naked egg is an egg without a shell. Using vinegar, you can dissolve the eggshell—without breaking the membrane that contains the egg.

   
What Do I Need? .
a few eggs  
white vinegar
a container big enough to hold all your eggs and a cover for the container
a big spoon
   
What Do I Do?

 

Here’s how you dissolve the shell from your eggs:

 
   
1. Place your eggs in the container so that they are not touching.  
   

2. Add enough vinegar to cover the eggs. Notice that bubbles form on the eggs. Cover the container, put it in the refrigerator, and let the eggs sit in the vinegar for 24 hours.

   

3. Use your big spoon to scoop the eggs out of the vinegar. Be careful—since the eggshell has been dissolving, the egg membrane may be the only thing holding the egg together. The membrane is not as durable as the shell.

   
4. Carefully dump out the vinegar. Put the eggs back in the container and cover them with fresh vinegar. Leave the eggs in the refrigerator for another 24 hours.
   
5. Scoop the eggs out again and rinse them carefully. If any of the membranes have broken, letting the egg ooze out, throw those eggs away.
   
6. When you’re done, you’ll have an egg without a shell. It looks like an egg, but it’s translucent—and the membrane flexes when you squeeze it. Very cool!
   
Whats Going On?  
When you submerge an egg in vinegar, the shell dissolves. Vinegar contains acetic acid, which breaks apart the solid calcium carbonate crystals that make up the eggshell into their calcium and carbonate parts. The calcium ions float free (calcium ions are atoms that are missing electrons), while the carbonate goes to make carbon dioxide—the bubbles that you see.
   
What Else Can I Try? .

• The reaction of the eggshell and the vinegar is an acid-base reaction. Calcium carbonate, a base, reacts with the acid in the vinegar to make carbon dioxide. Baking soda is also a base.

• Try mixing baking soda and vinegar and see what happens! Use this mixture to explode a plastic bag.

• Once you’ve made a few shell-less eggs, you can experiment by putting them in different solutions. Here’s how. Keep your eggs in the refrigerator until you're ready to do the experiments.

Share & Discuss

 

This activity first appeared in the Exploratorium publication, Human Body Explorations.

- - - Eggs Home Page - - - Kitchen Lab - - -

 

© Exploratorium - Use Policy - Privacy Policy