Chemistry in the Kitchen: The Science Behind Ice Cream

Legend has it that the Roman emperor Nero discovered ice cream. Runners brought snow from the mountains to make the first ice cream.

Making ice cream at home is easy – no mountain marathon required! Just read the instructions below and enjoy your very own homemade ice cream.

ice-cream-bowl
 Creative Commons LicensePhoto Credit: Jessicafm

Materials:
Sugar
Milk
Vanilla
Rock salt
Pint-size baggies – heavy duty
Gallon-size baggies – heavy duty
Measuring cup
Measuring spoons
Spoons

Procedure:
1. Fill the large bag about ½ full of ice.  Add 6 tablespoons of rock salt to the ice.

2. Put ½ cup of milk, ¼ teaspoon of vanilla, and 1 tablespoon of sugar into a smaller baggie and seal.  Put this inside another small baggie and seal.  This will prevent saltwater from seeping into your ice cream.

3. Place the double bagged small baggie into the larger baggie and seal.

4. Shake the baggie until you have ice cream. 

5. Remove the smaller baggie from the larger one.  Wipe off the water, then open it carefully and enjoy your ice cream! 

UPDATE: Check out our Science of Ice Cream video to learn more!

HOW TO: Christmas Chemistry Creations

This holiday season, we’re bringing you a series of fun science projects you can do at home – all with a holiday theme. In the first part in the series, Kat teaches us how to make the holidays sparkle!

Use this wonderful chemistry concoction to “grow” your own amazing Christmas decorations!

Things you will need:
20 Mule Team Borax – available at the grocery store with the laundry detergents
Pipe cleaners (also known as craft stems)
Wide mouthed Mason jar
String
Pencil
Parental Guidance
 

How to do it:
Shape the pipe cleaners into various shapes such as simple star shapes, circles, diamonds, angels, or whatever shape you wish.  Make sure the ornament shape fits easily inside your mason jar.
 
Tie a piece of string to your ornament and the other end of the string to the pencil. 
 
Fill your jar (with parental guidance of course!) with boiling water.
 
Add borax to the jar a tablespoon at a time.  Stir until it is dissolved before adding another tablespoon.  The formula that works best is 3 tablespoons of borax to each cup of water used.  Don’t worry if some un-dissolved borax is at the bottom of the jar.
 
Hang your pipe cleaner creation in the jar with the pencil across the top of the jar to suspend it.  The pipe cleaner should be fully immersed in the solution and hang freely without touching the bottom of the jar. 
 

Find a safe spot for your jar and leave it alone overnight.

The next morning you will have a beautiful crystal creation that you made yourself!

What’s going on here?
When you add borax to the hot water and stir you are creating a saturated solution.  What does this mean?  Well, it means that the water can hold no more borax (this is obvious when there is un-dissolved borax at the bottom of the jar).  Hotter water can dissolve more solute (in this case borax) than colder water can. When our saturated borax solution begins to cool, it can no longer hold as much borax as it could while hot (it is temporarily a supersaturated solution).  This “extra” borax attaches itself to the pipe cleaners in the form of crystals.