How to Write a Secret Message on the Inside of an Egg

With a couple of common household items you can create a cool effect that prints a message on the inside of a boiled egg, without showing up on the exterior shell of the egg. Use this as a fun effect for your kids or friends.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Alum
• Vinegar
• Fine Tipped Paint Brush
• Stove, Pot and Water
• Egg

1. Mix about a ½ ounce of alum with about a ½ pint of vinegar. Mix Well. Keep mixing until the alum is completely (or at least mostly) dissolved in the vinegar.

2. Dip your brush into the solution and write a message on the egg. The writing will spread out slightly, so make your message as fine as possible.

3. Let the egg dry completely. Place under a bright light for 10-15 minutes to speed up the drying process. If you do not let the writing dry completely, that it will just wash off in the next step.

4. Hard boil the egg. No special technique is required. Put your egg in a pot of water. Bring your pot of water to a boil then down to a simmer for 10-15 minutes.

5. Peel the egg to reveal the message (or give to someone else to open).

6. DO NOT EAT THE EGG!!

Tips & Warnings

• Alum can be found at most major grocery stores.
• Alum is a common food additive, but is not meant for direct consumption. You should not eat the egg painted with Alum.

[nightshift]

on 7/4/2009 Great article. This is the coolest trick. There is a great video on how to do this at http://slapshedstudio.blogspot.com/2009/07/how-to-send-secret-message-with-egg.html.