I would prefer using non perishable food flavouring to change pH levels.
Fun tip: Mix tobacco and distilled water in a foam cup. Dip a litmus paper into the solution, it will show whether the tobacco is acidic or basic, it help figure your tongue tolerance. You should learn how to use it accurately, if you didn't already learn.
Dispose the foam cup!
(P.S forget about exothermic reaction from earlier post, wrong notes)