Valentine's Day: Sweetness & Science

Post contributed by Jocelyne Adkins, Program Director/Educator

What better way to celebrate Valentine's Day than to conduct science experiments with candy? Our goal was to expose "secret" or unexpected ingredients in candy. Loralee Leavitt's book "Candy Experiments" proved to be an excellent resource! We are eager to try many more of these experiments in the future : )

Note: In our first experiment, we tested for acid, an ingredient in all sour foods and candy. We used Sour Patch Kids candy and there was little interaction bt. acid and base (baking soda) to cause a bubbling reaction, so this one experiment was re-performed on Friday with a truly sour candy, resulting in great success. Have fun looking at our experiments below!

Andrew: acid experiment with Sour Patch Kids

Leila: oil experiment with Starburst candies

Jackson, Caleb & Dexter: confectioner's glaze experiment with Jelly Belly candies

Candy is often coated with confectioner's glaze to polish and to protect the candy from sticking together. For this experiment, we submerged Jelly Bellies in warm water and to the students' delight, the candies shed their "skin", much like a snake! Candy companies use this same experiment to test the quality of their candies' coatings.
 

Xavier, Leila & Mikel observing the results of their experiments

 

Norah, Emily, Cassie & Dallis making observations

A group analysis of our experiments

Experiments with Jelly Bellies, Sour Patch Kids and Starburst

Starburst Candy: oil exposed on the surface of the water

Because oil is lighter than water, it floats. As the water cools, the oil will turn to a white waxy solid. Oil prevents candy from sticking to machinery and allows the candy to be chewy, soft and smooth.

Caleb's finger, sporting a "Jelly Belly" logo with edible ink that floated off the candy's skin or glaze

On Friday, we continued our science experiments with candy: We used colorful candies to expose how water density can vary. We also looked at the role of air bubbles to help objects float in water and experimented with a candy's shape/form to make a non-floating candy float on water.  

Skittles

 
In the above experiment, the colored sugar water dissolving off the candy is dense and sinks to the bottom. It pushes the less dense water out of the way. Soon the colors meet, however they do not mix because their density is similar. Eventually, the colors will mix, since water molecules are always moving! 

Emory and Joseph observing the colors beginning to mix

colors beginning to mix

Starlight mints and color density

The spreading pattern of the red and white colors in Starlight candy works because of the water density as described above. Note how the excess of red dye in one area of the candy (bottom) really becomes visible in the water bath...

Students observing the results of their experiments

Cake decorations float and sink, float and sink again and again

Andrew, Xavier (just behind Andrew), Anika and Laila

The density of the green sugar water deposited a pattern of color at the bottom of the plastic container, which was further accentuated by the raised design at the container's bottom.  Above, note how the area with 2 cake decorations is darker green, the area with 1 decoration is a lighter green and the area with no cake decorations is barely green.

Almost completely dissolved cake decorations

"Warheads" sour candy floating in water, dissolving their outer coating

Since our Sour Patch Kids candy experiment testing for acid yielded too mild of a reaction on Thursday, we re-performed the experiment on Friday using a very sour candy called "Warheads". After dissolving the outer candy coating and adding baking soda to the water, it was a bubbling extravaganza, indicating a very acidic candy indeed!

observing the bubbling reaction caused by baking soda mixed with sour candy

Joseph carefully adding baking soda to the sour candy

bubbles form as carbon dioxide gas is released

Hershey's Air Delight chocolate bar: aerated chocolate floats!

3 Musketeers Bar: filled with air, making it light, so it floats in water

Hershey's chocolate bar: dense, so it sinks in water

3 Musketeers bar, broken in half: eventually air bubbles should escape, and it will sink

Jessica and Leila with sunken taffy (the yellow candy)

We wrapped up the lesson manipulating the shape/form of the taffy, to make it float rather than sink: a bowl or boat shaped candy pushes aside more water than it weighs, making it float (I wish I would have remembered to take a photo of the floating taffy!). A ship made of heavy metal can float for the same reason: it pushes aside enough water, allowing it to float : )