Investigating acids

Today we did our first experiment. We tested PH levels of various liquids. Teacher made a very stinky purple water using red cabbage. (The water is PH neutral)
We found if the water turned pink, the liquid is an acid and if it turned blue/green it was alkaline.
We discovered something that surprised us, juice is bad for your teeth. So we should brush our teeth after foods and drinks with acid.
We discovered bread soda is an alkaline. Interestingly people used to use bread soda to clean their teeth before tooth paste.
Take a look at our findings.