Red cabbage may be used to determine whether a solution is acidic or basic.Red cabbage contains a pigment called flavin (an anthocyanin). This water soluble pigment is also found in apple skin, plums, poppies, cornflowers, and grapes. Very acidic solutions will turn anthocyanin a red color. Neutral solutions result in a purplish color. Basic solutions appear in greenish-yellow. Therefore, it is possible to determine the pH of a solution based on the color it turns the anthocyanin pigments in red cabbage juice. To prepare a solution of red cabbage juice indicator, chop some red cabbage into small pieces and cover them with boiling water. Allow the mixture to sit for approximately ten minutes. The indicator may now be used to test various solutions as to their acidity.
