An indicator is a substance that has the distinction of getting a different colour by it's contact with an acid or a base. We can made our home-made-indicator.
First, boil the lombard at home, we collect the boiled water into a glass, Filter it through a strainer and we have our liquid indicator.
To see how the colour changes we put in a glass the subtance that we want to study and add a spoonful of the liquid indicator.
If the substance is acidic. It turns red when you add the liquid indicator and, it is basic, it turns green or blue.
by María and Carmen Lucía