You’ve heard of the litmus test, but have you tried the cabbage juice test? I’m home schooling the kids, as the greeting says, and Thing 1 is working on a chemistry science unit at present. After she did her work with litmus paper, I made her some cabbage juice indicator. We didn’t try all the liquids she tested with litmus paper, but this pretty clearly shows the pH range (the milk of magnesia is basic and turns green, water is neutral and is bluish-purple, and vinegar is acidic and turns bright pink). I also showed her how you can tell when you have neutralized an acid or base. If you would like to play with this in your kitchen, all you need is a head of red cabbage and water . . . and whatever you what to test.
Boil 2 cups of water.
Add chopped red cabbage and let soak for 30 minutes. Strain out the cabbage and collect the liquid.
Add a few tablespoons of rubbing alcohol (isopropanol) if you want to keep your indicator around for a few weeks.
Have fun testing the pH of things in your home. The kids have a blast with this!
** Safety caution — don’t taste this stuff!