Neem seed oil: SAP value and fatty acids
Neem seed oil has a saponification value of 195.6 mg KOH/g. One gram needs 0.139 g of sodium hydroxide (NaOH) for bar soap or 0.196 g of potassium hydroxide (KOH) for liquid soap to turn fully into soap, before any superfat.
Key numbers
- SAP, NaOH
- 0.13944 g per g oil
- SAP, KOH
- 0.1956 g per g oil
- Saponification value
- 195.6 mg KOH/g
- Iodine value
- 74.1
- INS
- 122
- INCI name
- Azadirachta Indica Seed Oil
Example: 100 g of Neem seed oil with no superfat needs 13.9 g of 100% NaOH, or 19.6 g of 100% KOH. A 5% superfat uses 5% less.
In soap
Its main fatty acids in our cited profile are oleic (51.8%) and linoleic (20.8%). The eight fatty acids used in soap-quality scores make up 100% of the profile.
On its own it scores 27 for hardness, 0 for cleansing and 73 for conditioning, with a saturated : unsaturated split of 27 : 73.
Strong-smelling, bitter oil. Only supplier figures were usable; published lab values vary widely (some well under 150) because of extraction and quality.
Fatty-acid profile
| Fatty acid | % of fatty acids | Counts toward |
|---|---|---|
| lauric | 0% | hardness, cleansing, bubbly lather |
| myristic | 0% | hardness, cleansing, bubbly lather |
| palmitic | 19.6% | hardness, creamy lather |
| stearic | 7.8% | hardness, creamy lather |
| ricinoleic | 0% | conditioning, bubbly and creamy lather |
| oleic | 51.8% | conditioning |
| linoleic | 20.8% | conditioning |
| linolenic | 0% | conditioning |
Basis: AMB Express 2015 Table 1, commercial neem oil bought from local processors in North Cameroon (4 acids only).
Soap-quality scores (this oil alone)
| Hardness | 27 |
|---|---|
| Cleansing | 0 |
| Conditioning | 73 |
| Bubbly lather | 0 |
| Creamy lather | 27 |
| Iodine | 74 |
| INS | 122 |
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: 195.6 mg KOH/g (Median of sources' mgKoh_mid), from Chart of Saponification Values for Making Soap (averages compiled 2006 from distributors), Certified Lye. Printed value: NaOH 0.1372 / KOH 0.1932 g alkali per g oil.
Published values we checked:
- NaOH 0.1372 / KOH 0.1932 g alkali per g oil — Certified Lye
- 198 mg KOH/g — The Soapery (UK soap supplier)
Fatty acids and iodine: Solvent-free, enzyme-catalyzed biodiesel production from mango, neem, and shea oils via response surface methodology (AMB Express 2015; DOI 10.1186/s13568-015-0172-x), Springer Nature (peer-reviewed, open access). Also checked: MDPI (peer-reviewed, open access) (Table 3, iodine value row); Portland Press (peer-reviewed) (Abstract).
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 .