We “magically” changed the color of grape juice!
We had 2 different types of grape juice in the pantry: white grape with strawberry and regular dark grape juice.
We started with the white grape and strawberry juice.
I let each of them taste the juice before hand. Then I reminded them what happens when you mix an acid (like vinegar) with a base (baking soda). Finally, I asked them to make some predictions about what would happen if we mixed the juice and a tablespoon of baking soda together.
They were hoping for some serious fizz action!
We were a little disappointed. There was not much of a reaction at all.
I let them each taste the juice with the baking soda — THAT got a reaction!
Next we tried the dark grape juice.
Again, I let each of them taste the juice beforehand and we made some predictions.
This time the reaction was much more exciting!
As you can see in the picture, the juice fizzed a bit and went from a reddish color to a dark blue.
They were so excited!
Of course, the preschooler just had to try the juice… His face was priceless! (It was definitely salty and as he so eloquently put it, “Yuck!”)
Just why does the grape juice change color?
The juice acts like a pH indicator. It will change to a blue color when a base is added (like baking soda) and to a red color with an acid.
I’m thinking next time we may try to change it back by adding vinegar or lemon juice, but at this point in our experiment my preschooler and kindergartner were ready to find new adventures.
Looking for more science fun to try at home?