Stearic Acid
Saponification values, fatty acid makeup, and what this oil does in a bar of soap.
Saponification values
Grams of lye needed to saponify one gram of stearic acid. Multiply by your oil weight, then apply your superfat.
- NaOH (bar soap)
- 0.141
- KOH (liquid soap)
- 0.198
- Iodine
- 2
- INS
- 196
INCI: Stearic Acid
Fatty acid profile
| Fatty acid | Percentage |
|---|---|
| Stearic | 99% |
Soap qualities at 100%
What a bar made entirely of stearic acid would score. Almost nobody soaps a single oil at 100% — this is here so you can see what the oil contributes to a blend. The shaded band is the range most makers aim for in a finished recipe.
What that means in a recipe
Contributes a lot of hardness (99), so it firms a bar up and helps it unmould cleanly and last in the dish.
Derived from the numbers above rather than written by hand, so it stays in step with the data. Tendencies, not guarantees — your oils, water, and technique all move the result.
Oils that behave similarly
Closest matches by fatty acid makeup — the usual starting point when you have run out of stearic acid and need a substitute. Check the lye maths again after swapping: SAP values differ even between oils that behave alike.
- Soybean, fully hydrogenated (soy wax)SAP 0.137 NaOH
- Kokum ButterSAP 0.135 NaOH
- Illipe ButterSAP 0.132 NaOH
- Sal ButterSAP 0.132 NaOH
- Mango Seed ButterSAP 0.136 NaOH