In this video, we learn how to make a pH indicator out of red cabbage. Red cabbage will work because when it absorbs an acid then it changes color and reflects light differently. To do this at home, try to add different types of acids to the cabbage. Start off by putting the cabbage in the blender, then make sure it's shredded. Now, put it in a jar with some boiling hot water. Shake up the jar, then place the water into some separate cups. Now, add chemicals into the juice and depending on the color it changed, you will be able to judge how acidic it is.