Science with Dr. Bob: Cabbage as a pH Indicator

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BAR HARBOR, Maine (WABI) - Today for Science with Dr. Bob we are working with an unconventional way to check the pH certain liquids.

"Cabbage shows its colors as a pH indicator"

· Plants are the primary producers of food and oxygen on our planet, but they also provide tools for humans to work with, including tools for science.

· As we move away from using artificial colorings to using natural colorings in our products, plants provide new options for this color palette.

· The red pigment molecule in many plants including red cabbage is called anthocyanin, and anthocyanin changes its color dramatically based on acidity.

· Acidity is such an important property of liquids that we name it - acidity and we measure it - with a scale we call pH.

· The color changing capability of anthocyanin makes it not only a useful natural food coloring, but a versatile tool for some beautiful and fun science.

· Some of the solutions we will use today can be dangerous if concentrated, so we will be careful with this experiment.

For more information, including the recipes we used for the red cabbage pH indicator and for the colored solutions we produced in this segment, visit