Making a PH reactive liquid is an easy science fair project that could be made in a single evening with great results. This project requires little more than red cabbage and some basic household supplies. This project is an easy way to visually determine if a liquid or powder is an acid or a base. With the plurality of liquids and powders in your household, this allows for vast experimentation.
There are few required materials for this project.
The first and most important item is red cabbage. One large cabbage will yeild more PH liquid than is necessary, so it is probably best to cut it in half (or get a very small cabbage).
Also, a standard coffee filter is recommended.