Wheat germ oil: SAP value and fatty acids
Wheat germ oil has a saponification value of 188.5 mg KOH/g. One gram needs 0.134 g of sodium hydroxide (NaOH) for bar soap or 0.189 g of potassium hydroxide (KOH) for liquid soap to turn fully into soap, before any superfat.
Key numbers
- SAP, NaOH
- 0.134378 g per g oil
- SAP, KOH
- 0.1885 g per g oil
- Saponification value
- 188.5 mg KOH/g
- Iodine value
- 123
- INS
- 66
- INCI name
- Triticum Vulgare Germ Oil
Example: 100 g of Wheat germ oil with no superfat needs 13.4 g of 100% NaOH, or 18.8 g of 100% KOH. A 5% superfat uses 5% less.
In soap
Its main fatty acids in our cited profile are linoleic (57.3%) and palmitic (17.4%). The eight fatty acids used in soap-quality scores make up 97.8% of the profile.
On its own it scores 18 for hardness, 0 for cleansing and 80 for conditioning, with a saturated : unsaturated split of 18 : 80.
Wheat germ oil has a lot of unsaponifiable matter (vitamin E, sterols). Use at low levels. 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 | 0.1% | hardness, cleansing, bubbly lather |
| palmitic | 17.4% | hardness, creamy lather |
| stearic | 0.5% | hardness, creamy lather |
| ricinoleic | 0% | conditioning, bubbly and creamy lather |
| oleic | 15.3% | conditioning |
| linoleic | 57.3% | conditioning |
| linolenic | 7.2% | conditioning |
Basis: USDA FDC SR Legacy 171014 (Oil, wheat germ), converted to % of total fatty acids.
Soap-quality scores (this oil alone)
| Hardness | 18 |
|---|---|
| Cleansing | 0 |
| Conditioning | 80 |
| Bubbly lather | 0 |
| Creamy lather | 18 |
| Iodine | 123 |
| INS | 66 |
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: 188.5 mg KOH/g (Median of sources' mgKoh_mid (no Codex/pharmacopoeia standard found)), from Physical Properties of Fats and Oils (compiled from Ullmann's, Bailey's, AOCS and AFCEG handbooks), Deutsche Gesellschaft für Fettwissenschaft (DGF). Printed value: 190 - 196 mg KOH/g.
Published values we checked:
- 190 - 196 mg KOH/g — Deutsche Gesellschaft für Fettwissenschaft (DGF)
- NaOH 0.1319 / KOH 0.1858 g alkali per g oil — Certified Lye
- 187 mg KOH/g — The Soapery (UK soap supplier)
- 180-200 mg KOH/g — Parchem Fine & Specialty Chemicals (distributor)
Fatty acids and iodine: USDA FoodData Central, SR Legacy 171014: Oil, wheat germ, USDA Agricultural Research Service. Also checked: Deutsche Gesellschaft für Fettwissenschaft (DGF) (Iodine value table).
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 .