Edible Science Projects

Make learning about chemistry yummy and delicious by doing your own home science projects and eat the results.  If you like playing with your food, these projects are perfect!
These fun projects require equipment that is clean and safe.  Glassware should be heatproof and not shatter easily.  Participants in these experiments must take care with hot liquids or syrups as they can scald and burn.  Never use dishes, pans, or utensils that you have used for non-food experiments.

Rock Candy

Any one can make rock candy at home with basic kitchen ingredients. You need sugar, water, and food coloring, if desired.  If you want colorful and zingy rock candy, add your favorite flavoring. .

Pour one cup of water into a pan and stir in three cups of sugar.  Bring to a boil and turn off the heat.

Pour the solution into a clean heat-resistant jar.  Boiling syrup scalds the skin if the glass shatters.  A canning jar is safe and some people say that peanut butter jars work well.  Beware of using normal kitchen glasses, jars, or bottles. Adult supervision is vital for safety. 

Tie a couple of pieces of string on a pencil and weight down with sterilized paper clips on the bottom of the string.  Do not use nuts or fishing sinkers to keep the string straight as they may contain lead or other dangerous contaminants. Suspend the weighted string in the solution using the pencil to hold it up.  Make sure nothing touches the sides or bottom of the jar. 

You can also use clean Popsicle sticks on string to make the candy.  They are safer than using paper clip weights.

The cooling sugar solution clings to the string and piles up rock crystals. It takes around 48 hours to absorb most of the sugar water. Pull out and hang to dry. Be sure to cut the paper clips from the string.  

.Save any leftover solution.  It will not go bad quickly. Just boil again, and start over.

Why it works

This works because sugar is a crystal.   Boiling makes the water molecules grow farther apart.  This allows the water to absorb more of the sugar.  As the water cools, the molecules draw back together. It leaves less room so the sugar molecules, having nowhere to go, stick to the string. This reaction, called crystallization, builds up until you have a sweet treat of rock candy.

Make your own butter.

Pour half of a container of whipping cream into a clean jar with a tight lid.  Carefully whip it up with a mixer.  When it forms soft peaks, add in a bit of sugar, food color, or flavoring if you like. 

Add the other half of the whipping cream.  Screw the lid on tight and shake the jar for five or ten minutes.  A large clump will form in the mixture.  Unscrew the lid and pour off the liquid.  This is buttermilk.  The clump that is left is butter that you made yourself.  Refrigerate the leftover butter and milk as soon as possible after using.

Handle the jar with care and use a towel or hot pad, if necessary, to hold it so it will not slip from your hands.  When you get tired, let the next eager hands take over for a while.

Why it works

This works because whipping the cream fluffs it out. When you add the rest of the cream and shake the jar, the molecules come back together and form a lump, which gives you butter for your toast or potatoes.  

Make your own geyser

This experiment is a dramatic and awesome demonstration of the forces of nature.  You need a two-liter bottle of cola and a roll of Mentos candies.  People say that diet cola works better, has no sugar, and is less likely to mess up your world.  This makes a big mess, so take it outside to a large lawn or field.

Place the bottle on a solid surface and remove the lid so you can add the Mentos. You need to drop the whole roll of Mentos into the bottle of soda all at once. 

You can roll paper into a tube.  Slip the roll of candy into the paper, hold it over the mouth of the bottle, and let it all go in at once.  Alternatively, use a funnel large enough to let the candy fall through without being stuck.  Make sure that you and your audience stand back!  Cola  spews out in a geyser as high as 18 feet. Make sure someone is recording it on video.

Pour off any remaining cola, retrieve the Mentos, and eat them.  Chemistry is so sweet and rewarding!

Why it works

The jury is out on this one.

Soda bustles with carbon dioxide bubbles, which the bottling plant inject under pressure to    suspend them in the soda. Water molecules attract each other and link to form a net around the carbon dioxide bubbles. Water molecules push away from each other creating   tension on the surface.

 Dropping the Mentos into the soda breaks the surface tension.  The water expands and   forms new bubbles.  When the candies fall to the bottom of the bottle of soda, bubbles form over every pit of the candy. The gas makes the soda whoosh out in a geyser. 

Other explanations and opinions exist about why it works but no one can say for sure.


Find more delicious chemistry experiments on the Internet.   Chemistry provides lots of fun and learning opportunities but the best ones are the ones you eat afterwards.  Always take care to keep your experience fun and safe.

About.com Chemistry
Exploratorium.edu  cooking/candy/sugar