In our science studies at homeschool, we tested some solutions to find out if they were acids or bases. This Acid/Base Experiment was a lot of fun for the kids, who later recorded the results of the experiment in their notebooks.
We poured all kinds of liquids into containers ( water, milk, vinegar, soap, coffee, tea, urine, honey, soy sauce, etc.) We then put a litmus paper into every container. If the paper turned red, the solution was an acid, and if it turned blue, the solution was a base.