Sesame oil in soap making
Published by The Soap Brain Team
Sesame oil is a conditioning soap-making oil rich in linoleic acid (41%). A gram of it turns to soap with about 0.137 g of NaOH (lye). It makes a mild, gentle bar and pairs well with a harder, cleansing oil. Most soapers use it at 5–15% of their oils.
Fatty-acid profile
Sesame 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.
Sesame oil is about 14% saturated fat and 80% 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 |
|---|---|---|
| Linoleic acid | 41% | a polyunsaturated fatty acid that is very conditioning but oxidises readily — a driver of DOS (dreaded orange spots) at high levels |
| Oleic acid | 39% | a monounsaturated fatty acid that makes a gentle, conditioning, moisturising bar with a slick, lower lather and a slower trace |
| Palmitic acid | 9% | a saturated fatty acid that builds a hard, long-lasting bar with a stable, creamy lather |
| Stearic acid | 5% | a saturated fatty acid that adds hardness and a thick, stable lather; a large share can speed up trace |
Sesame oil in the bar
Sesame oil gives a mild, low, slick lather on its own. Blended with a bubbly, cleansing oil it contributes body and mildness while the partner oil supplies the bubbles.
Sesame 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 Sesame 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 Sesame oil
Out of Sesame 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) |
|---|---|---|---|---|
| Sesame oil (this oil) | 14 | 0 | 80 | 0.137 |
| Argan oil | 13 | 0 | 80 | 0.135 |
| Soybean oil | 15 | 0 | 83 | 0.136 |
| Corn oil | 15 | 0 | 83 | 0.135 |
| Olive oil | 16 | 0 | 83 | 0.135 |
Using Sesame oil in a recipe
One gram of Sesame oil needs about 0.137 g of NaOH (sodium hydroxide) to turn fully to soap, within a documented range of 0.133–0.139 g/g across sources. The calculator below uses this value; always confirm the lye weight before you mix.
Its iodine value is about 109 — a higher value, pointing to a softer, more conditioning bar that is more prone to rancidity (DOS). 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 Sesame oil at roughly 5–15% of their oils.
Maker's note: Mild conditioning; traditional/Ayurvedic soaping oil.
Calculate lye for Sesame oil
The calculator below is pre-loaded with Sesame 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).
Loading the calculator…
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.
- Codex Alimentarius CXS 210-1999 — Named Vegetable Oils (Tables 1–2) — SAP 186–195 mg KOH/g
- From Nature With Love — Saponification Chart — SAP range
- Artiz Soap — SAP Value Table — SAP cross-check
- The Conscious Life — Sesame oil (USDA SR28) — fatty-acid profile
SAP data last updated · 51 oils covered.
Sesame oil soap FAQ
- Can you make soap with 100% Sesame oil?
- It is not recommended. Sesame oil shows its best in a blend, usually up to about 15% 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 Sesame oil?
- A 5% superfat is a safe, common starting point for recipes using Sesame 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 Sesame oil speed up or slow down trace?
- Sesame 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.