September 23, 2018 | F.Lab

Testing pH is useful for a wide variety of reasons, from testing homemade soap to make sure it is balanced and not lye heavy, to optimizing hydroponics, to satisfying simple curiosity. Yet pH testing strips or meters might not be readily available.

One thing that usually is, however, is red cabbage. This simple protocol allows you to take red cabbage and use it to do basic and reliable pH testing.

The protocol produces red cabbage juice, which can be used if kept refrigerated for at least 2-3 days afterward. Make sure you are using distilled water if you mix samples with the red cabbage juice, otherwise the pH of your water might interfere with the results.

1. Materials

Red Cabbage (1 head)
Blender (1)

Measuring Cup (1 cup)
Mixing Bowl (1)
Dropper/Straw (1, optional)

Distilled water (1 cup)

2. Steps

1. Chop up 3-4 leaves of red cabbage;

2. Pour 1 cup of distilled water into the chopped cabbage;

3. Blend the mixture;

4. Strain the mixture and save the liquid and;

5. Apply one drop of liquid on the test subject.