I chopped up a few red cabbage leaves and boiled them for about an hour in all, to be left with about 30ml of a deep purple liquid. Purpose: to experiment and see if it will indeed turn into a shade of blue when added to my soap mixture.
I’ve read a few websites where people have tried it out and it worked. Like this blog where a mom dyed eggs using red cabbage and they turned out blue; or this other blog where someone made a Rainbow Bento using various vegetable dyes, including red cabbage for a nice shade. The bento does look really pretty:
But by far the most interesting to me was finding this page, where it gave a rough explanation about red cabbage dye being used as a natural pH indicator in labs. Here’s the photo that caught my attention:
Is that cool or what? Now, seeing that soap is basic, when I add it to my soap mixture at trace, it could turn blue (pH8), green (pH9) or yellow. Yellow is most likely at this stage since saponification may not be complete. But will its colour change when the pH drops to the 8-10 range after the soap has hardened after 24 hours?
EeeEEE I CANNOT WAIT to try this out and take some photos!