Sal butter (sal seed fat): SAP value and fatty acids
Sal butter (sal seed fat) has a saponification value of 190 mg KOH/g. One gram needs 0.135 g of sodium hydroxide (NaOH) for bar soap or 0.190 g of potassium hydroxide (KOH) for liquid soap to turn fully into soap, before any superfat.
Key numbers
- SAP, NaOH
- 0.135448 g per g oil
- SAP, KOH
- 0.19 g per g oil
- Saponification value
- 190 mg KOH/g
- INCI name
- Shorea Robusta Seed Butter
Example: 100 g of Sal butter (sal seed fat) with no superfat needs 13.5 g of 100% NaOH, or 19.0 g of 100% KOH. A 5% superfat uses 5% less.
In soap
Its main fatty acids in our cited profile are stearic (45.1%) and oleic (38.2%). The eight fatty acids used in soap-quality scores make up 91.6% of the profile.
On its own it scores 51 for hardness, 0 for cleansing and 41 for conditioning, with a saturated : unsaturated split of 51 : 41.
India sets a legal standard for refined sal seed fat (FSSAI / Agmark); search results quote 180–195, but the official document could not be opened, so it is not recorded as a source.
Fatty-acid profile
| Fatty acid | % of fatty acids | Counts toward |
|---|---|---|
| lauric | 0% | hardness, cleansing, bubbly lather |
| myristic | 0% | hardness, cleansing, bubbly lather |
| palmitic | 6% | hardness, creamy lather |
| stearic | 45.1% | hardness, creamy lather |
| ricinoleic | 0% | conditioning, bubbly and creamy lather |
| oleic | 38.2% | conditioning |
| linoleic | 2% | conditioning |
| linolenic | 0.3% | conditioning |
Basis: Single study, Food Chem X 2025 Table 5 (Soxhlet-extracted sal seed oil, GC).
Soap-quality scores (this oil alone)
| Hardness | 51 |
|---|---|
| Cleansing | 0 |
| Conditioning | 41 |
| Bubbly lather | 0 |
| Creamy lather | 51 |
Each score adds up certain fatty acids, the way Soap Ledger scores a whole recipe. They are for comparing recipes; they don't predict how a bar will feel, and they say nothing about safety or skin.
Sources
SAP value: 190 mg KOH/g (Median of sources' mgKoh_mid (no Codex/pharmacopoeia standard found)), from Sal Butter: Typical Product Specifications, Parchem Fine & Specialty Chemicals (distributor). Printed value: 185 - 195 mg KOH/g.
Published values we checked:
- 185 - 195 mg KOH/g — Parchem Fine & Specialty Chemicals (distributor)
- 187-193 mg KOH/g — Wikipedia
Fatty acids: Thapa et al. (2025) Process optimization for the extraction of Shorea robusta (Sal) seed oil using response surface methodology and its characterization: a sustainable approach to oil valorization. Food Chem X 32:103380. doi:10.1016/j.fochx.2025.103380, Elsevier (open access, peer-reviewed).
NaOH and KOH values are converted from mg KOH/g with the molar masses 39.997 and 56.106 and rounded to 6 decimals, exactly as in the Soap Ledger app. Real oils vary by origin, grade and lot: check your supplier's certificate of analysis. Verify every weight before you make this, and follow lye safety. Not a safety or compliance certification.
Last updated .