Definition: A chemical compound used as an acid-base indicator, turning pink in the presence of an alkali & remaining colorless in a solution containing acid.
Why the heck would you need this stuff?
If you are going to embark on making soap using KOH and Catherine Failor's methods, you need to have phenolphthalein on hand so you can ensure your soap is "done".
You only need one drop to test a soap sample so you can be sure that you don't have an excess of lye in your soap. Working with KOH soapmaking, you can't rely on a simple "tongue" test.
Comes with instructions and Catherine Failor's books explain thoroughly how to test your soap with phenolphthalein.
