Jatropha oil (physic nut): SAP value and fatty acids
Jatropha oil (physic nut) has a saponification value of 193.75 mg KOH/g. One gram needs 0.138 g of sodium hydroxide (NaOH) for bar soap or 0.194 g of potassium hydroxide (KOH) for liquid soap to turn fully into soap, before any superfat.
Key numbers
- SAP, NaOH
- 0.138121 g per g oil
- SAP, KOH
- 0.19375 g per g oil
- Saponification value
- 193.75 mg KOH/g
- Iodine value
- 105
- INS
- 89
- INCI name
- Jatropha Curcas Seed Oil
Example: 100 g of Jatropha oil (physic nut) with no superfat needs 13.8 g of 100% NaOH, or 19.4 g of 100% KOH. A 5% superfat uses 5% less.
In soap
Its main fatty acids in our cited profile are oleic (44.7%) and linoleic (32.8%). The eight fatty acids used in soap-quality scores make up 99% of the profile.
On its own it scores 21 for hardness, 0 for cleansing and 78 for conditioning, with a saturated : unsaturated split of 21 : 78.
Jatropha seeds and oil contain toxic phorbol esters; not edible. Only one usable (non-peer-reviewed) source was readable; published lab values vary widely. 'Soapnut seed oil' is SoapCalc's alias. Use the supplier COA. Only one published source was found for this value; confirm it against your supplier's certificate of analysis.
Fatty-acid profile
| Fatty acid | % of fatty acids | Counts toward |
|---|---|---|
| lauric | 0% | hardness, cleansing, bubbly lather |
| myristic | 0.1% | hardness, cleansing, bubbly lather |
| palmitic | 14.2% | hardness, creamy lather |
| stearic | 7% | hardness, creamy lather |
| ricinoleic | 0% | conditioning, bubbly and creamy lather |
| oleic | 44.7% | conditioning |
| linoleic | 32.8% | conditioning |
| linolenic | 0.2% | conditioning |
Basis: Toxicology Reports 2025 Table 1, single J. curcas seed-oil profile (lauric reported as not detected).
Soap-quality scores (this oil alone)
| Hardness | 21 |
|---|---|
| Cleansing | 0 |
| Conditioning | 78 |
| Bubbly lather | 0 |
| Creamy lather | 21 |
| Iodine | 105 |
| INS | 89 |
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: 193.75 mg KOH/g (Single source only), from Chemical Analysis of Jatropha curcas (three oil samples), S. V. Lele (oil-technology consultant website, svlele.com). Printed value: 195.5; 193.6; 192 mg KOH/g.
Published values we checked:
Fatty acids and iodine: Jatropha curcas seed oil for possible human consumption: A toxicological assessment of its phorbol esters (Toxicol Rep 2025; DOI 10.1016/j.toxrep.2024.101870), Elsevier (peer-reviewed, open access). Also checked: Elsevier (peer-reviewed, open access) (Table 1, brown-dry stage, 4 Botswana sites); Royal Society of Chemistry (peer-reviewed, open access) (Table 10, Jatropha curcas oil column).
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 .