Natural Acid and Base Indicators - ThoughtCo
Sep 16, 2019· Curry Powder: Curry contains the pigment curcumin, ... Esculin is colorless at pH 1.5 but becomes fluorescent blue at pH 2. Get the best effect by shining a black light on the indicator. ... Washing Soda: As with baking soda, washing soda fizzes in an acidic solution but not in a basic solution. Cite this Article Format.