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Kokum butter in soap making

Published by The Soap Brain Team

Kokum butter is a hardening soap-making oil rich in stearic acid (56%). A gram of it turns to soap with about 0.134 g of NaOH (lye). It firms up a bar with a stable, creamy lather and blends well with conditioning oils. Most soapers use it at 5–15% of their oils.

Fatty-acid profile

Kokum butter is mainly a hardening oil: its saturated fatty acids give a firm, long-lasting bar with a stable, creamy lather, and it is usually blended with more conditioning oils to keep the finished soap mild.

Kokum butter is about 59% saturated fat and 38% unsaturated — that saturated majority is what lets it firm up a bar and hold a stable lather.

Fatty-acid composition of Kokum butter
Fatty acid Share What it does in soap
Stearic acid 56% a saturated fatty acid that adds hardness and a thick, stable lather; a large share can speed up trace
Oleic acid 38% a monounsaturated fatty acid that makes a gentle, conditioning, moisturising bar with a slick, lower lather and a slower trace
Palmitic acid 3% a saturated fatty acid that builds a hard, long-lasting bar with a stable, creamy lather

Kokum butter in the bar

Expect a dense, low-bubble, creamy lather from Kokum butter — rich and steady rather than foamy. Pairing it with a bubbly oil adds the fluffy bubbles it lacks.

Because it is rich in palmitic and stearic acids, Kokum butter tends to bring a batch to trace quickly and set up fast, so work briskly and keep fragrances that accelerate trace in mind. The upside is a firm bar that usually unmoulds within a day or two.

In a blend Kokum butter is a hardening, bar-firming component. Use it in small amounts; combine it with conditioning liquid oils so the bar stays mild rather than brittle.

Closest substitutes for Kokum butter

Out of Kokum butter? 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.

Kokum butter compared with its closest substitute oils
Oil Hardness Cleansing Conditioning SAP (NaOH)
Kokum butter (this oil) 59 0 38 0.134
Illipe butter 61 0 38 0.135
Cocoa butter 62 0 38 0.137
Sal butter 51 0 40 0.132
Cupuaçu butter, deodorized 50 0 41 0.135

Using Kokum butter in a recipe

One gram of Kokum butter needs about 0.134 g of NaOH (sodium hydroxide) to turn fully to soap, within a documented range of 0.13–0.139 g/g across sources. The calculator below uses this value; always confirm the lye weight before you mix.

Its iodine value is about 35 — a low value, pointing to a hard, long-lasting bar with good shelf life. 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 Kokum butter at roughly 5–15% of their oils.

Maker's note: Very hard butter with strong structural firmness; a good shea substitute.

Calculate lye for Kokum butter

The calculator below is pre-loaded with Kokum butter. 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.

SAP data last updated · 51 oils covered.

Kokum butter soap FAQ

Can you make soap with 100% Kokum butter?
It is not recommended. Kokum butter 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 Kokum butter?
A 5% superfat is a safe, common starting point for recipes using Kokum butter; 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 Kokum butter speed up or slow down trace?
Because it is rich in palmitic and stearic acids, Kokum butter tends to bring a batch to trace quickly and set up fast, so work briskly and keep fragrances that accelerate trace in mind. The upside is a firm bar that usually unmoulds within a day or two.