- a clear glass
- baking soda
- cranberry juice
- lemon juice
- tablespoon and cup measuring utensils
- Measure out one cup of cranberry juice and pour it into the glass.
- Measure out one tablespoon of baking soda and pour it into the glass as well. Observe the reaction! Look out for bubbling, changes in juice color, foaming, etc.
- Wait a minute or two and jot down observations as the time passes by.
- At the end of the two minutes, measure out and add two tablespoons of lemon juice, and again, observe the reaction again. This time, look out for the color changing, the foaming going down, etc.
- Way to go! You just completed a base/acid reaction. Yay for food chemistry!
HOW DOES IT WORK?
Cranberries…possibly the official fruit of the Thanksgiving season! Besides being a delicious treat, cranberries contain a pigment (anthocyanins) that change color depending if they are reacting with an acid or a base. (Two chemistry terms here used to describe materials)! Because cranberries fall into the acid category (you can even taste this acid – through the tartness of the berry or juice), we can actually create a reaction and change color with our cranberry juice by adding a base…our baking soda!
The baking soda should foam up a bit when it hits our acidic juice, then react with the cranberry color pigments to turn the cranberry juice from red into a deep purple. When you add the lemon juice (an acid), it should neutralize the basic baking soda to react with the pigment again and bring the juice back to a red color after a few minutes. (It will also begin to break up the foam). For further exploration, test the order of the ingredients you mix, or experiment with other acids (like vinegar). Isn’t food science interesting?!