i have these jars, each one in the midst of a curcumin extraction and a piperine extraction. i put a few ml's of each liquid into a beaker and mixed them together. it was an orange cloudy liquid.

anyway i put a pinch of baking soda in the reaction, then the all the liquid turned blood red, like verry red. then i added citric acid to the solution and it turned back to the original color. i was able to keep repeating this.

pretty cool, kinda like an indicator