Palm oil vs palm kernel oil in soap
Two different oils from the same fruit. Palm oil is pressed from the pulp and is mostly palmitic and oleic acid; palm kernel oil comes from the seed and is a lauric oil like coconut, about half lauric acid. It takes 22.8 % more lye, so never swap them without recalculating: weigh the lye for palm kernel oil and use palm oil, and the bar below comes out lye-heavy, at −1.2 % superfat.
The published figures
| Palm oil | Palm kernel oil | |
|---|---|---|
| Saponification value, mg KOH/g | 190–209 | 230–254 (typical 245) |
| Used by the calculator, mg KOH/g | 199.5 (midpoint) | 245.0 (typical) |
| SAP for NaOH, g/g | 0.1422 | 0.1747 |
| Iodine value, g I₂/100 g | 50–55 | 14.1–21 |
| INS (SAP − IV) | 147 | 227 |
| Melting point, °C | — | — |
| Unsaponifiable matter, % | ≤ 1.2 | ≤ 1 |
| Name on a soap label | Sodium Palmate | Sodium Palm Kernelate |
Each oil alone
| Palm oil | Palm kernel oil | Usual range | |
|---|---|---|---|
| Hardness | 50 | 76 | 29–54 |
| Cleansing | 2 | 66 | 12–22 |
| Conditioning | 51 | 18 | 44–69 |
| Bubbly lather | 2 | 66 | 14–46 |
| Creamy lather | 48 | 10 | 16–48 |
A single oil’s hardness, cleansing and the rest are the same sums the calculator shows for a recipe, applied to that one oil. They explain what the oil brings to a blend; they do not predict how a soap of only that oil would feel.
Swapping one for the other
Gram for gram, palm kernel oil takes 22.8 % more lye than palm oil. For a kilogram of oil at a 5 % superfat, that is 135.1 g of sodium hydroxide for palm oil and 165.9 g for palm kernel oil.
In the bar below, where it is 30 % of the oils, weigh the lye for one and put in the other without recalculating, and the superfat moves:
| Lye weighed for | Oil used | Superfat |
|---|---|---|
| Palm oil | Palm kernel oil | 10.8 %far more oil left: recalculate |
| Palm kernel oil | Palm oil | −1.2 %lye-heavy: never swap without recalculating |
The superfat is the share of the oils the lye leaves unsaponified, planned here at 5 %; below zero, there is more lye than the oils can take. Put the oil you actually have in the lye calculator and it works out the lye for that oil.
The same bar with either
The bar: 30 % of the one or the other, at a 5 % superfat, for 1,000 g of oils. The rest: 40 % olive oil, 25 % coconut oil, and 5 % castor oil.
| With palm oil | With palm kernel oil | Usual range | |
|---|---|---|---|
| Sodium hydroxide, g | 141.5 | 150.7 | |
| Hardness | 42 | 50 | 29–54 |
| Cleansing | 17 | 37 | 12–22 |
| Conditioning | 55 | 45 | 44–69 |
| Bubbly lather | 22 | 41 | 14–46 |
| Creamy lather | 29 | 17 | 16–48 |
| Iodine value | 56 | 45 | 41–70 |
| INS | 153 | 177 | 136–165 |
| Linoleic and linolenic acid, % | 9.1 | 6.6 |
Open the bar with palm oil Open the bar with palm kernel oil
Fatty-acid profile
| Fatty acid | Palm oil | Palm kernel oil | |
|---|---|---|---|
| Caprylic acid | C8:0 | 0.0 | 4.3 (2.4–6.2) |
| Capric acid | C10:0 | 0.0 | 3.8 (2.6–5) |
| Lauric acid | C12:0 | 0.3 (0–0.5) | 50.0 (45–55) |
| Myristic acid | C14:0 | 1.3 (0.5–2) | 16.0 (14–18) |
| Palmitic acid | C16:0 | 43.4 (39.3–47.5) | 8.3 (6.5–10) |
| Stearic acid | C18:0 | 4.8 (3.5–6) | 2.0 (1–3) |
| Oleic acid | C18:1 | 40.0 (36–44) | 15.5 (12–19) |
| Linoleic acid | C18:2 | 10.5 (9–12) | 2.3 (1–3.5) |
| Arachidic acid | C20:0 | 0.5 (0–1) | 0.1 (0–0.2) |
The figure the calculator uses for each oil, as a percentage of its fatty acids, with the published range in brackets.
Recipes with palm oil
- Piped soap cupcakes 60 % of the oils
- Classic olive, coconut and palm bar 30 % of the oils
- Everyday bar, the usual three 30 % of the oils
- Apricot seed scrub bar 25 % of the oils
- Everyday bar, gentler 25 % of the oils
- Gardener's pumice scrub bar 25 % of the oils
Recipes with palm kernel oil
- African black soap homage 45 % of the oils
Guides
Other comparisons
Where these numbers come from
Palm Oil
Verbatim mirror of the FAO file CXS_210e.pdf; the official FAO link (https://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%3A%2F%2Fworkspace.fao.org%2Fsites%2Fcodex%2FStandards%2FCXS%2B210-1999%2FCXS_210e.pdf) was Cloudflare-gated at retrieval. Table 1 (Section 3.1) = mandatory GLC fatty-acid ranges, % of total fatty acids, ND = not detectable (<=0.05%). Table 2 (Appendix 'Other quality and composition factors') gives saponification value, iodine value (Wijs) and unsaponifiable matter of CRUDE oils; the Appendix is explicitly ADVISORY (a product not meeting it may still conform). This print predates the 2021-2025 amendments; the 2024 additions (avocado, camellia seed, sacha inchi, high-oleic soya bean) are not included.
Palm Kernel Oil
Verbatim mirror of the FAO file CXS_210e.pdf; the official FAO link (https://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%3A%2F%2Fworkspace.fao.org%2Fsites%2Fcodex%2FStandards%2FCXS%2B210-1999%2FCXS_210e.pdf) was Cloudflare-gated at retrieval. Table 1 (Section 3.1) = mandatory GLC fatty-acid ranges, % of total fatty acids, ND = not detectable (<=0.05%). Table 2 (Appendix 'Other quality and composition factors') gives saponification value, iodine value (Wijs) and unsaponifiable matter of CRUDE oils; the Appendix is explicitly ADVISORY (a product not meeting it may still conform). This print predates the 2021-2025 amendments; the 2024 additions (avocado, camellia seed, sacha inchi, high-oleic soya bean) are not included.
The source of the typical saponification value. Table VII reproduces PORIM's survey of Malaysian palm kernel oil (Siew and Berger, PORIM Technology No. 6, 1981): saponification value range printed '243 - 349', a misprint for 243-249, mean 245; iodine value 16.2-19.2, mean 17.8; unsaponifiable matter 0.1-0.8 %, mean 0.3; mean fatty acids C6 0.3, C8 4.4, C10 3.7, C12 48.3, C14 15.6, C16 7.8, C18 2.0, C18:1 15.1, C18:2 2.7 %. Rossell, King and Downes (JAOCS 62:221-230, 1985, Table X) compare their own authentic samples with this survey, which 'originally analyzed 118 samples plus a further 44 of the 1983 crop'.
Corroboration. The authors' analyses of two English and Hamburg palm-nut (palm kernel) oils: saponification equivalents 225 and 227 (free acid 4.4 and 7.7 %), i.e. 249.3 and 247.1 mg KOH/g by the book's formula 56,100 / equivalent.