What sort of preservatives should I use for my Cold Processed soap formula? How long is the shelf life using these preservatives? Will humidity affect my bar?


Preservatives: A properly saponified and formulated bar of soap will not require preservatives.

The only time he might require a preservative is if the Superfat value is too high, leaving a high percentage of unsaponified oils.

Recommend staying somewhere around a 4%-5% superfat.

Humidity: Again, a high superfat will have problems, mold, oxidation, etc.

Shelf Life: Again, a high superfat will have a shorter shelf life. A properly saponified bar should last four years or more. We have soap that has lasted six years sitting in a high humidity un-air-conditioned space.