Cold process soap is in a category of its own when it comes to adding scent. That lovely fragrance or essential oil may behave perfectly in lotion, bath fizzies, scrubs and other products, but behave terribly in cold process soap. Why is this and how can a soapmaker prevent lost soap batches due to misbehaving fragrance?
First, please note that the terms, “fragrance” and “scent” refer to both essential oils and fragrance oils in this piece.
It is important to understand why cold process soapmaking is so hard on fragrance. When the maker stirs lye into water, the pH of the mixture is 14, which is as alkaline as possible. The pH is still 14 when the lye water is added to oils, and the soap remains caustic until saponification is complete at around the twenty-four hour mark. Not all fragrances perform well in such an alkaline environment; the vexing reactions range from ricing or acceleration to seizing, aka, “Soap on a Stick.”
To avoid such issues, what should a soapmaker do?
- Check the fragrance specifications. The information provided by the supplier should state that the product is skin safe. While that is important, it simply ensures that the fragrance is suitable for skin use projects such as melt & pour soap, lotion and bath fizzies. It does not ensure a smooth cold process soapmaking experience. Not all suppliers offer the information, but when they do report how the fragrance behaves, it is a huge help to their customers. Choose fragrances tested in cold process soap if you don’t want to experiment with it yourself.
- Check the usage rate for the fragrance in cold process soap and do not exceed it. Doing so may cause issues in making the soap. Usage rates are supplied to ensure a safe product, but overuse may also affect the behavior of the fragrance.
- Finally, take the time to make a test batch. It is much better to find out that a fragrance will seize or separate the soap in a one-pound batch than in a ten- or twenty-pound batch! Yes, it takes time and materials, but it will reveal potential issues.
To avoid issues with scent and cold process soapmaking, take time to research the desired fragrance or scent blend before you begin. Choose cold process tested scents whenever possible and don’t skip that test batch!
Until next time, may all your days be filled with bubbles and wax.
Beth Byrne, for Making Soap, Cosmetics & Candles Magazine