Turn an Uncooked Egg into a Rubber Ball

by Denise Dickerson (Landover, MD.)

This fun food science experiment shows what happens when you soak an uncooked egg in vinegar for several days. As the egg sits in the vinegar, the shell slowly dissolves and leaves behind the soft membrane underneath.

The result is an egg that feels rubbery and bouncy, giving kids a hands-on way to explore chemical reactions and the structure of an egg.

This activity is part of our Food Science Experiments collection where you can explore kitchen chemistry, growing experiments, and edible science projects.

What You Need

• 1 uncooked egg (make sure the shell is not cracked)
• Clear container with a lid, large enough to hold the egg and vinegar
• Enough vinegar to cover the egg

Directions

Step 1: Place the egg in a clear container with a lid. Pour in enough vinegar to completely cover the egg.

Step 2: Cover the container and leave the egg in the vinegar for 3 to 4 days. You may notice bubbles forming on the shell as the vinegar starts reacting with it.

Step 3: Carefully remove the egg from the vinegar and gently rinse it with water. Observe how the shell is gone and the egg now feels soft and rubbery.

Rubber Egg Experiment Video

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What Happens?

The eggshell is mostly made of calcium carbonate. Vinegar contains acetic acid, which reacts with the calcium carbonate in the shell. As the acid breaks down the shell, you may see bubbles form. Those bubbles are carbon dioxide gas being released during the reaction.

After the shell dissolves, only the egg’s thin membrane is left. That membrane is soft and flexible, so the egg feels rubbery instead of hard. The egg may also look slightly larger because some liquid moves through the membrane during the soaking process.

Why It Matters in Cooking

This experiment helps kids understand how acids react with foods and food surfaces. Vinegar is used in many recipes and preservation methods, and this experiment shows that acidic ingredients can cause visible changes in food.

• Kids see how acids react with calcium-rich materials
• They learn that food has layers and structure
• It connects chemistry to ingredients used in the kitchen
• It builds observation and patience over several days

Science Questions

• What happened to the eggshell?
• Why did bubbles form on the egg?
• How does the egg feel after soaking in vinegar?
• Why does the egg stay together even after the shell is gone?
• Does the egg look different in size after a few days?

Ways to Extend the Experiment

• Compare two eggs soaked for different amounts of time.
• Measure the egg before and after soaking.
• Observe what happens if the vinegar is changed halfway through.
• Compare the rubber egg with a fresh uncooked egg.

Safety Tips

• Handle the finished egg gently because it can still burst.
• Wash hands after handling raw egg.
• Do not eat the egg after the experiment.
• Clean the work area well after finishing.

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