Making magic potion is simple! Chop a head of red cabbage into small pieces and add it to a pan with enough water to cover it. Boil the cabbage uncovered for about 15 minutes, stirring occasionally, let it cool, and strain the juice into a jar or bowl. (Save the cooked cabbage for dinner.)
If you want to avoid the stove, chop half a head of red cabbage and blend it with about 3 cups of water. Strain the liquid through a colander and then through a coffee filter in a plastic bag with one corner cut off. Blended cabbage juice makes longer-lasting bubbles and turns a slightly brighter shade of blue!
Now, pour about 1/4 cup of the cabbage juice, or “magic potion” into two clear glasses or bowls and set them on a white piece of paper (so you can watch the color change.)
Try adding a Tablespoon of baking soda to one glass of potion. What happens?
To the second cup of potion, add a few Tablespoons of vinegar or lemon juice. Notice anything different?
Finally, mix the two cups of potion together.
Why did the color change when you added two different chemicals to the magic potion? Everything in our world is made of very tiny pieces called atoms. Atoms are so small that if you blow up a balloon, it will contain about a hundred billion billion atoms of the gases that make up air. Atoms are often bonded to other atoms to form a group of linked atoms called a molecule.
Acids usually dissolve in water to form free-floating hydrogen atoms. Bases are the opposite and take up free hydrogen atoms. The molecules in the cabbage juice magic potion change when exposed to an acid or base, making the potion change color. Vinegar is an acid, which turns the potion pink and baking soda is a base, which turns it blue or green.
When you mix the vinegar potion and baking soda potion together, a chemical reaction occurs and you make Carbon Dioxide gas. That’s why you see bubbles!
Try adding some other liquids to your magic potion. Can you tell whether they are acids or bases?
Here’s a short video that shows you exactly how to do the experiment!