Rice bran oil in soap making
Published by The Soap Brain Team
Rice bran oil is a conditioning soap-making oil rich in oleic acid (42%). A gram of it turns to soap with about 0.133 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
Rice bran 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.
Rice bran oil is about 23% saturated fat and 75% 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 | 42% | a monounsaturated fatty acid that makes a gentle, conditioning, moisturising bar with a slick, lower lather and a slower trace |
| Linoleic acid | 33% | a polyunsaturated fatty acid that is very conditioning but oxidises readily — a driver of DOS (dreaded orange spots) at high levels |
| Palmitic acid | 21% | a saturated fatty acid that builds a hard, long-lasting bar with a stable, creamy lather |
| Stearic acid | 1.6% | a saturated fatty acid that adds hardness and a thick, stable lather; a large share can speed up trace |
Rice bran oil in the bar
Rice bran 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.
Rice bran 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 Rice bran 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 Rice bran oil
Out of Rice bran 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) |
|---|---|---|---|---|
| Rice bran oil (this oil) | 23 | 0 | 75 | 0.133 |
| Baobab oil (refined) | 24 | 0 | 70 | 0.135 |
| Marula oil | 22 | 0 | 76 | 0.139 |
| Wheat germ oil | 18 | 0 | 80 | 0.133 |
| Avocado oil | 17 | 0 | 80 | 0.133 |
Using Rice bran oil in a recipe
One gram of Rice bran oil needs about 0.133 g of NaOH (sodium hydroxide) to turn fully to soap, within a documented range of 0.128–0.142 g/g across sources. The calculator below uses this value; always confirm the lye weight before you mix.
Its iodine value is about 98 — 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 Rice bran oil at roughly 5–15% of their oils.
Maker's note: Mild lather; adds a "sheen"/gloss to the bar surface.
Calculate lye for Rice bran oil
The calculator below is pre-loaded with Rice bran 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.
- Codex Alimentarius CXS 210-1999 — Named Vegetable Oils (Tables 1–2) — SAP 180–199 mg KOH/g; Table 1 fatty acids: C16:0 14–23, C18:0 0.9–4.0, C18:1 38–48, C18:2 21–42, C18:3 0.1–2.9
- SoapCalc oil list — SAP, iodine
- From Nature With Love — Saponification Chart — SAP range
- The Conscious Life — Rice bran oil (USDA SR28) — stearic 1.6, palmitic 16.9, myristic 0.7 g per 100 g of oil — a ~95% basis, the glycerol backbone being the rest
SAP data last updated · 51 oils covered.
Rice bran oil soap FAQ
- Can you make soap with 100% Rice bran oil?
- It is not recommended. Rice bran 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 Rice bran oil?
- A 5% superfat is a safe, common starting point for recipes using Rice bran 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 Rice bran oil speed up or slow down trace?
- Rice bran 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.