Thanks to this forum, I have had some remarkable success this weekend with some cream soap formulations. I have identified a formula mix and am now going to begin beta testing with a few people, and the question of preservatives has popped up.
A similar formula uses Methylisothiazolinone and Phenoxyethanol as preservatives. I am looking for suggestions from you for preservatives that would be good for a shave cream blend of Palmitic acid, Stearic acid with glycerin.
1. Which do you recommend (one or both of the above?)
2. Alternatives that might be acceptable
3. What will happen to the soap without them (I suppose rotting, but how long typically will it be before this happens?)
4. What kinds of percent/quantity would be necessary to safely insure the soap preservation from spoiling; ie: what % would I need to add after the batch is finished to insure a quality product. (2 types are listed in my target formula, and I assume both serve a specific function for the product, but I am looking for variations that might work and satisfy the need).
Many thanks for the help!