The cranberry harvest has hit the shelves, making it the perfect time of year to experiment with this under-appreciated berry. Okay, so this quick science trick uses cranberry juice, not whole fresh cranberries, but it’s still a fun seasonal project for kids!
I set up a few test tubes about 1/3 of the way full with cranberry juice and laid out baking soda and lemon juice.
First, Travis added 1 teaspoon baking soda to one test tube. It fizzed instantly, always the most exciting part.
When the bubbles settled, the cranberry juice was noticeably more yellow.
ow add 1 teaspoon lemon juice (or citric acid) to the same test tube. It will return (almost) to the original color. The color became sort of striated in ours, so the return to normal was clearest near the bottom of the tube.
The science at work here is base (baking soda) first neutralizing the anthocyanins in the juice, and then the acid returning it to normal. Travis had fun simply experimenting from there! He thought we might make it extra yellow by adding 2 teaspoons baking soda (that one was really fizzy!).
Next time, we’ll think of other solutions we can add, like soda or baking powder.