Soap Box Blog

The Importance of Testing

Date: April 30, 2013

How do we know if we made your soap right?  The only way we're confident that the final product is OK to ship is by testing it in our laboratory.

Testing for pH is not enough because that only tells part of the story, and it is not the important part. The pH of soap can vary a good bit, and the soap might still be OK to use, or it might not. The better way is to test for excess lye (unreacted caustic soda) because any leftover lye could irritate your skin. The test is called titration. Though it’s a simple chemical procedure to perform, it requires very accurate measurement of the amount of acid or base it takes to neutralize what might be left over in the soap.

Excess lye is bad, but a little excess oil is actually good for your skin. Too much excess oil can promote rancidity, so it’s necessary to stay within an acceptable range. We take a sample of soap from every batch and run a titration to make sure it is OK before we approve it for sale.

Testing is better than assuming or guessing! Green Mountain Soap is not only naturally pure, it’s safe to use.

Precise amount of soap shavings measured out

Phenolphthalein added to warm lye/alcohol mixture

Soap shavings are added and stirred

Excess fatty acid neutralizes lye/alcohol mixture

Mixture clears, indicating negative for excess lye.  Records updated for each batch of soap processed.