Hemp seed oil: SAP value and fatty acids
Hemp seed oil has a saponification value of 190.8 mg KOH/g. One gram needs 0.136 g of sodium hydroxide (NaOH) for bar soap or 0.191 g of potassium hydroxide (KOH) for liquid soap to turn fully into soap, before any superfat.
Key numbers
- SAP, NaOH
- 0.136018 g per g oil
- SAP, KOH
- 0.1908 g per g oil
- Saponification value
- 190.8 mg KOH/g
- INCI name
- Cannabis Sativa Seed Oil
Example: 100 g of Hemp seed oil with no superfat needs 13.6 g of 100% NaOH, or 19.1 g of 100% KOH. A 5% superfat uses 5% less.
In soap
Its main fatty acids in our cited profile are linoleic (50.9%) and oleic (19.3%). The eight fatty acids used in soap-quality scores make up 96.1% of the profile.
On its own it scores 11 for hardness, 0 for cleansing and 86 for conditioning, with a saturated : unsaturated split of 11 : 86.
Published sources for this oil differ by more than 3%, so checking your supplier's certificate of analysis matters more than usual.
Fatty-acid profile
| Fatty acid | % of fatty acids | Counts toward |
|---|---|---|
| lauric | 0% | hardness, cleansing, bubbly lather |
| myristic | 0% | hardness, cleansing, bubbly lather |
| palmitic | 7.2% | hardness, creamy lather |
| stearic | 3.4% | hardness, creamy lather |
| ricinoleic | 0% | conditioning, bubbly and creamy lather |
| oleic | 19.3% | conditioning |
| linoleic | 50.9% | conditioning |
| linolenic | 15.3% | conditioning |
Basis: Peer-reviewed GC of three cold-pressed hemp seed oils from Romanian varieties (Plants 2025, Table 1), mean; linolenic = ALA + GLA.
Soap-quality scores (this oil alone)
| Hardness | 11 |
|---|---|
| Cleansing | 0 |
| Conditioning | 86 |
| Bubbly lather | 0 |
| Creamy lather | 11 |
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: 190.8 mg KOH/g (Median of sources), from Latif S., Anwar F. (2009) Physicochemical studies of hemp (Cannabis sativa) seed oil using enzyme-assisted cold-pressing. Eur. J. Lipid Sci. Technol. 111:1042-1048. doi:10.1002/ejlt.200900008, Wiley-VCH (peer-reviewed). Printed value: 181–186 mg KOH/g.
Published values we checked:
- 181–186 mg KOH/g — Wiley-VCH (peer-reviewed)
- 188–194 mg KOH/g — From Nature With Love (soap/cosmetic supplier)
- 191 mg KOH/g — The Soapery (UK soap supplier)
- NaOH 0.1359 / KOH 0.1914 g alkali per g oil — Certified Lye
Fatty acids: Chemical Profile, Bioactive Constituents and In Vitro Growth Stimulation Properties of Cold-Pressed Hemp Seed Oils from Romanian Varieties: In Vitro and In Silico Evaluation. Plants 14(22):3465 (2025), MDPI. Also checked: U.S. Department of Agriculture, Agricultural Research Service (Fatty acid nutrients (g/100 g food)).
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.
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