Stearic Acid (triple-pressed, ~50:50 C16/C18)
INCI Stearic Acid. Saponified with NaOH it is listed as Sodium Stearate, with KOH as Potassium Stearate. Also: Octadecanoic acid (commercial), Stearic acid 50%, Triple pressed stearic acid, Stearic acid NF.
Calculate a 100 % Stearic Acid (triple-pressed, ~50:50 C16/C18) bar
Published values
| Saponification value | 206–212 mg KOH/g |
| Used by the calculator | 209.0 mg KOH/g (midpoint) |
| SAP for NaOH | 0.1490 g/g |
| Iodine value | ≤ 0.5 g I₂/100 g |
| INS (SAP − IV) | 209 |
| Melting point | — |
| Unsaponifiable matter | — |
A bar made of 100 % Stearic Acid (triple-pressed, ~50:50 C16/C18)
Conventional qualities summed from the fatty-acid groups; a single-oil bar is a reference point, not a recipe.
Fatty-acid profile
| Fatty acid | Published range, % | Used | |
|---|---|---|---|
| Myristic acid | C14:0 · saturated | ≤ 2 | 2.0 |
| Palmitic acid | C16:0 · saturated | 45–49 | 47.0 |
| Stearic acid | C18:0 · saturated | 50–54 | 52.0 |
| Oleic acid | C18:1 | ≤ 0.5 | 0.5 |
| Linoleic acid | C18:2 | ≤ 1.5 | 1.5 |
Where these numbers come from
Specification table on the product page: acid value, saponification value, iodine value, titre, colour, C14/C16/C18/C18:1/C18:2 composition limits.
EMERSOL 132 NF row: acid value 205-211 mg KOH/g, iodine value 0.5 max, titer 54.5-55.5 C; EMERSOL 120 (double pressed): acid value 205-210, iodine value 5-7, titer 53.7-54.7 C, C16 38-44 %, C18 43-48 %.
Brochure PDF (uploaded 2012) used only for the grade comparison in notes; its text-extracted table rows are offset by one line, so the product page is the authoritative source for SA-1850.
Commercial 'stearic acid' used in soap is a palmitic/stearic mixture, not pure C18. Primary values are the producer specification for Wilmar WILFARIN SA-1850 (Stearic Acid 50 %, triple pressed): acid value 205-211 mg KOH/g, saponification value 206-212 mg KOH/g, iodine value 0.5 max (% I2 absorbed = g/100 g), titre 55-57 C, colour 0.3/3 max (Lovibond R/Y), composition C14 2 % max, C16 45-49 %, C18 50-54 %, C18:1 0.5 % max, C18:2 1.5 % max. Emery Oleochemicals' EMERSOL 132 NF (triple-pressed tallow stearic acid) has matching limits: acid value 205-211 mg KOH/g, iodine value 0.5 max, titer 54.5-55.5 C (additional source; Emery's page gives no SAP). Free fatty acid: SAP is essentially the acid value; use directly for lye calculation. Titre is a solidification point, so meltingPointC is null. Other grades differ (Wilmar brochure: SA-1892 92 % stearic AV ~195-199/SAP ~196-200, titre 66-70 C; SA-1865 65 % AV ~202-209; rubber grades SA-1810/1804 AV >= 195 with IV up to 4-10) - see notes if modelling a 90 %+ C18 grade. INCI and salt names are the standard CosIng entries, not re-verified on CosIng in this session.
This record is part of the open ingredient database (ODbL). Found an error or a better primary source? The dataset is on GitHub; corrections with a document link are welcome.