Coconut oil vs palm kernel oil in soap
Palm kernel oil behaves like coconut oil in soap, a hard bar with a quick, bubbly lather: on its own it scores 76 for hardness and 66 for cleansing, against coconut oil’s 80 and 68. It carries more oleic acid and takes 4.5 % less lye, so the two are not interchangeable: weigh the lye for coconut oil and use palm kernel oil, and the bar below drops to 3.6 % superfat. It raises the same questions of sourcing as palm oil.
The published figures
| Coconut oil | Palm kernel oil | |
|---|---|---|
| Saponification value, mg KOH/g | 248–265 | 230–254 (typical 245) |
| Used by the calculator, mg KOH/g | 256.5 (midpoint) | 245.0 (typical) |
| SAP for NaOH, g/g | 0.1829 | 0.1747 |
| Iodine value, g I₂/100 g | 6.3–10.6 | 14.1–21 |
| INS (SAP − IV) | 248 | 227 |
| Melting point, °C | 23–26 | — |
| Unsaponifiable matter, % | ≤ 1.5 | ≤ 1 |
| Name on a soap label | Sodium Cocoate | Sodium Palm Kernelate |
Each oil alone
| Coconut oil | Palm kernel oil | Usual range | |
|---|---|---|---|
| Hardness | 80 | 76 | 29–54 |
| Cleansing | 68 | 66 | 12–22 |
| Conditioning | 9 | 18 | 44–69 |
| Bubbly lather | 68 | 66 | 14–46 |
| Creamy lather | 12 | 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 4.5 % less lye than coconut oil. For a kilogram of oil at a 5 % superfat, that is 173.7 g of sodium hydroxide for coconut oil and 165.9 g for palm kernel oil.
In the bar below, where it is 25 % 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 |
|---|---|---|
| Coconut oil | Palm kernel oil | 3.6 %recalculate |
| Palm kernel oil | Coconut oil | 6.3 %recalculate |
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: 25 % of the one or the other, at a 5 % superfat, for 1,000 g of oils. The rest: 50 % olive oil, 20 % shea butter, and 5 % castor oil.
| With coconut oil | With palm kernel oil | Usual range | |
|---|---|---|---|
| Sodium hydroxide, g | 138.6 | 136.7 | |
| Hardness | 37 | 37 | 29–54 |
| Cleansing | 17 | 17 | 12–22 |
| Conditioning | 59 | 61 | 44–69 |
| Bubbly lather | 21 | 21 | 14–46 |
| Creamy lather | 25 | 24 | 16–48 |
| Iodine value | 59 | 61 | 41–70 |
| INS | 146 | 140 | 136–165 |
| Linoleic and linolenic acid, % | 8.4 | 8.5 |
Open the bar with coconut oil Open the bar with palm kernel oil
Fatty-acid profile
| Fatty acid | Coconut oil | Palm kernel oil | |
|---|---|---|---|
| Caprylic acid | C8:0 | 7.3 (4.6–10) | 4.3 (2.4–6.2) |
| Capric acid | C10:0 | 6.5 (5–8) | 3.8 (2.6–5) |
| Lauric acid | C12:0 | 49.2 (45.1–53.2) | 50.0 (45–55) |
| Myristic acid | C14:0 | 18.9 (16.8–21) | 16.0 (14–18) |
| Palmitic acid | C16:0 | 8.9 (7.5–10.2) | 8.3 (6.5–10) |
| Stearic acid | C18:0 | 3.0 (2–4) | 2.0 (1–3) |
| Oleic acid | C18:1 | 7.5 (5–10) | 15.5 (12–19) |
| Linoleic acid | C18:2 | 1.8 (1–2.5) | 2.3 (1–3.5) |
The figure the calculator uses for each oil, as a percentage of its fatty acids, with the published range in brackets.
Recipes with coconut oil
- Hundred percent coconut bar 100 % of the oils
- Zero-superfat coconut laundry bar 100 % of the oils
- Seawater marine soap 90 % of the oils
- Coconut liquid dish soap 85 % of the oils
- Sea salt bar 80 % of the oils
- Solid dish and kitchen bar 80 % of the oils
Recipes with palm kernel oil
- African black soap homage 45 % of the oils
Guides
Other comparisons
Where these numbers come from
Coconut 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.
Slip melting point 23-26 C (Ph. Eur. 2.2.15); unsaponifiable max 1.0 %; refractive index (40 C) ca. 1.449.
JP XVIII 'Coconut Oil': melting point 20-28 C; acid value NMT 0.2; saponification value 246-264; unsaponifiable matter NMT 1.0 %; iodine value 7-11.
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.