Tamanu (foraha) oil in soap making
Published by The Soap Brain Team
Tamanu (foraha) oil is a conditioning soap-making oil rich in oleic acid (38.1%). A gram of it turns to soap with about 0.139 g of NaOH (lye). It makes a mild, gentle bar and pairs well with a harder, cleansing oil. Most soapers use it at 1–5% of their oils.
Fatty-acid profile
Tamanu (foraha) oil is a gentle, conditioning oil, mostly unsaturated fatty acids that leave a mild, moisturising bar with a softer, lower lather. It pairs naturally with a harder, more cleansing oil to firm the bar up and add bubbles. Because its polyunsaturated (linoleic/linolenic) share is on the higher side, watch the total across the whole recipe and consider a modest antioxidant to guard against rancidity and DOS.
Tamanu (foraha) oil is about 30% saturated fat and 68% unsaturated — that unsaturated majority is what makes it conditioning and slower to trace, but softer on its own.
| Fatty acid | Share | What it does in soap |
|---|---|---|
| Oleic acid | 38.1% | a monounsaturated fatty acid that makes a gentle, conditioning, moisturising bar with a slick, lower lather and a slower trace |
| Linoleic acid | 29.8% | a polyunsaturated fatty acid that is very conditioning but oxidises readily — a driver of DOS (dreaded orange spots) at high levels |
| Palmitic acid | 15.8% | a saturated fatty acid that builds a hard, long-lasting bar with a stable, creamy lather |
| Stearic acid | 14.1% | a saturated fatty acid that adds hardness and a thick, stable lather; a large share can speed up trace |
| Linolenic acids (C18:3) | 0.3% | the polyunsaturated C18:3 family — deeply conditioning but the most prone to rancidity; keep the combined polyunsaturated total modest |
Tamanu (foraha) oil in the bar
Expect a dense, low-bubble, creamy lather from Tamanu (foraha) oil — rich and steady rather than foamy. Pairing it with a bubbly oil adds the fluffy bubbles it lacks.
Tamanu (foraha) oil traces at a fairly typical pace; how fast the whole batch moves will depend mostly on the other oils, your temperatures and any fragrance you add.
In a blend Tamanu (foraha) oil is the conditioning, skin-feel component and can often make up the bulk of the oils. Add a firmer, more cleansing oil — coconut, palm or a hard butter — to bring hardness and bubbles the finished bar would otherwise miss.
Closest substitutes for Tamanu (foraha) oil
Out of Tamanu (foraha) oil? These oils behave most like it in a bar — ranked by how close their hardness, cleansing and conditioning profile and lye (SAP) requirement are. The numbers are predicted properties for a 100% single-oil bar, not a safety guide; always recalculate the lye when you swap an oil.
| Oil | Hardness | Cleansing | Conditioning | SAP (NaOH) |
|---|---|---|---|---|
| Tamanu (foraha) oil (this oil) | 30 | 0 | 68 | 0.139 |
| Cottonseed oil | 26 | 1 | 69 | 0.137 |
| Baobab oil (refined) | 24 | 0 | 70 | 0.135 |
| Emu oil | 30 | 0 | 60 | 0.138 |
| Marula oil | 22 | 0 | 76 | 0.139 |
Using Tamanu (foraha) oil in a recipe
One gram of Tamanu (foraha) oil needs about 0.139 g of NaOH (sodium hydroxide) to turn fully to soap, within a documented range of 0.128–0.147 g/g across sources. The calculator below uses this value; always confirm the lye weight before you mix.
Its iodine value is about 89 — a moderate value, a good all-round balance of hardness and conditioning. Iodine value is only a rough guide, not a hard rule, but it gives you a feel for how a bar built around this oil will wear.
Most soapers use Tamanu (foraha) oil at roughly 1–5% of their oils.
Maker's note: Rich, dark conditioning oil; its strong scent, colour and cost keep it to a small amount. Do NOT make medical claims about it.
Calculate lye for Tamanu (foraha) oil
The calculator below is pre-loaded with Tamanu (foraha) oil. Enter your weights, add other oils, and it works out the exact NaOH (lye) weight, water and quality numbers. Always weigh lye, oils and water — never measure by volume, wear gloves and eye protection, and add lye to water (never the reverse).
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Where these numbers come from
Every figure on this page is backed by at least two independent references, listed below — so you can check our work instead of taking our word for it.
- From Nature With Love — Saponification Chart — SAP range
- ResearchGate — Tamanu oil purification trials — SAP 180 (refined) → 206 (crude); oleic 25–40%
- PMC (2025) — Calophyllum inophyllum seed-oil characterisation — fatty-acid profile (GC-FID, Table 1): palmitic 15.75, stearic 14.08, oleic 38.13, linoleic 29.77, α-linolenic 0.25
- OCL Journal — Tamanu oil properties — iodine index 82–98; the contested high-stearic cluster (30.2 ± 4.36%)
SAP data last updated · 51 oils covered.
Tamanu (foraha) oil soap FAQ
- Can you make soap with 100% Tamanu (foraha) oil?
- It is not recommended. Tamanu (foraha) oil shows its best in a blend, usually up to about 5% of the oils. On its own the bar would be unbalanced — too soft or low-lathering for everyday use.
- What superfat should I use with Tamanu (foraha) oil?
- A 5% superfat is a safe, common starting point for recipes using Tamanu (foraha) oil; adjust to taste once you know how the finished bar feels. Never drop to 0% or below without a deliberate reason — the calculator will ask you to confirm it.
- Does Tamanu (foraha) oil speed up or slow down trace?
- Tamanu (foraha) oil traces at a fairly typical pace; how fast the whole batch moves will depend mostly on the other oils, your temperatures and any fragrance you add.