Chop cabbage into small pieces. This liquid is at about pH 7. Pour about 50 - 100 mLs of your red cabbage indicator into each 250 mL beaker. Add your various household solutions to your indicator until you see a color change. You could do a neutralization experiment with the indicator.
Red cabbage contains a pigment called flavin.
This pigment is also found in red poppies, blue cornflowers, grapes, and apple skin. Depending on the pH of the fruit or plant the pigment will give a different color. Phenolphthalein is a commonly used indicator available from most chemical supply companies in its concentrated form. A small concentration of phenolphthalein is used as a laxative in Ex-Lax. Never use concentrated phenolphthalein as a laxative.