By Loralee Leavitt
Photos by Guy Cali Associates, Inc.
Have you ever wondered just what is in the treats you collect at Halloween time? With three simple science experiments, you can discover some of the ingredients yourself.
We have taste buds on our tongue for acid. When they're stimulated, we perceive a sour taste. In other words, if candy tastes sour, it contains acid. Most fruit-flavored candy contains citric acid, the sour chemical in lemons.
To test for acid, try this:
- Dissolve your candy in a half-cup of water. (WARHEADS and SweeTARTS work well.)
- Sprinkle in a spoonful of baking soda.
- If you see bubbles, the candy water contains acid.
Baking soda reacts with acid to form carbon dioxide gas. The gas makes bubbles in the water.
Many kinds of chewy candy, like taffy, are made with oil. This keeps the candy from sticking to the machinery when it's made. Food science professor Dr. Frost Steele explains that oil also helps keep the candy smooth, soft, and chewy.
To test for oil, try this:
- Disslove your candy in a cup of hot tap water. (Try Starburst candy and see what happens.
- Look for shiny puddles floating on the surface.
- When the water cools, you may see a white, waxy layer on top.
The kinds of oils used in these candies melt in hot water, forming the shiny puddles. In colder water, the oil can cool into a white, waxy solid. Since oil is lighter than water, it floats.
Candy makers often mix dyes to create colors.
To separate the colors, try this:
- Cut a rectangle from a coffee filter for each piece of candy you are going to test.
- Wet a piece of colored candy. (Brown M&M'S candy and Skittles candy work well.
- Fold the coffee-filter paper vertically.
- Dab the candy onto the paper, one inch from the bottom.
- Then stand the paper up in a half-inch of water with the colored dot above the waterline. Water should start creeping up the paper.
- When the water reaches the top, take out the paper and see if your dye has separated into different colors. (If the colors are hard to see, lay the paper on a white plate.)
After the colored dye dissolves, the moving water carries it up the paper. Dyes that dissolve more quickly travel faster. Soon the dyes separate, allowing you to see each color.