Ludvic

I don't think there is another safe method to make soap without strong basic chemical... Only potassium Hydroxide, more safe than sodium but really difficult to find! :D

Right Man! Sorry for this big mistake! :D

I dilute the ph indicator with the water, add water when you see the liquid get more clear. You can check all things and if you put some paper in this liquid you can create a useful "paper indicator" Sorry for the english, thank you so much for the comment

Yes, the water need to get more clear the solution, if you don't dilute with water you can't see the different when the indicator mixed with other substance. Drop a paper in the solution for 24 h and after let it dry.. Cut the paper in little piece and test on a varius chemical, rubbing on a bar of soap and you see a basic element... This method isn't really accurate, you can buy the strips indicator for cheap but this experiment is really awesome