Adventures in Chemistry: Why cabbage is a pH indicator

Other than being delicious, full of antioxidants, and an amazing example of artificial selection, Cabbage is chock full of fascinating chemistry! The anthocyanin molecules that make red cabbage red are not always red. They are pH indicators, meaning that they will change colour with acidity. Here the anthocyanins are extracted from the cabbage (umm, I made cabbage soup), and then the reasons why the anthocyanins change colour with pH are discussed. An amazing rainbow of cabbage juice can be observed, and you can easily repeat this experiment to recreate your own universal pH indicator at home!