Select another ingredient and stir it into the glass. Observe what happens. You can continue to add ingredients to the glass or clean the glass out and begin again using different ingredients. What happens Depending on the ingredient added to the red cabbage water, the water will turn either green or pink. The concoction will also foam over at some point.
Red cabbage contains a chemical that acts as an indicator.
Since both acids and bases can dissolve in water, they form solutions that often look alike. Scientists need to be able to identify which solutions are acids and which are bases. The indicator found in red cabbage is used for this. The pink colour indicates the presence of acid. The green colour indicates the presence of alkali or base.