Testing Handmade Soap with Phenolphthalein: A Comprehensive Guide
Phenolphthalein, commonly known as phenol, is a pH indicator frequently used in the soap-making process to ensure purity. This article will guide you through the proper use of phenolphthalein in testing your handmade soap for the presence of lye (sodium hydroxide and potassium hydroxide). We will cover the properties of phenol, the correct method for testing, and tips for ensuring accurate results.
Understanding Phenolphthalein
Phenolphthalein is a pH indicator that changes color from clear to a shade of purple when in the presence of a base substance, such as sodium hydroxide and potassium hydroxide. These substances are highly caustic, making phenolphthalein an essential tool for testing for lye presence in handmade soap.
Preparation and Usage of Phenolphthalein
For phenolphthalein to function correctly, it must be mixed with 99% isopropyl alcohol. This mixture ensures the indicator is reactive to lower concentrations of base materials, resulting in more accurate and reliable test results. It's crucial to prepare this solution in-house to maintain quality control, as many commercially available indicators may use less pure alcohol, which can affect their reactivity.
To begin testing your soap, simply apply a drop of the phenolphthalein solution to the soap. If lye is present, the soap will instantly change color. A light pink color indicates a weak presence of lye, while a bright purple color suggests a high concentration of lye. Note that the test must be conducted after the soap has set for 2-3 days to ensure that the saponification process is complete. Remember, using high amounts of olive oil can slow down this process, so take that into account as well.
Where to Obtain Phenolphthalein
Phenolphthalein can be challenging to find, but we stock it for immediate shipment. The product comes in a 2-ounce dropper bottle, ready to use for your testing needs. It has a shelf life of 12 months, but may still function for a couple of years, although its reactivity may decrease over time. Therefore, it's wise to test the solution periodically to ensure its effectiveness.
Conclusion and Tips
Testing your handmade soap with phenolphthalein is an essential step in ensuring that your product is safe and free from contamination. By following the proper method and maintaining quality control, you can achieve accurate test results. Remember to use a reliable soap calculator on all your recipes and follow their guidelines for best results.
Testing your handmade soap with phenolphthalein is a straightforward process, but performing it correctly is crucial for your product's safety. By understanding the properties of phenolphthalein, preparing it properly, and following best practices, you can ensure that your soap meets the highest standards of quality and purity.