Tallow (beef fat) in soap making
Published by The Soap Brain Team
Tallow (beef fat) is a hardening soap-making oil rich in oleic acid (43%). A gram of it turns to soap with about 0.138 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 20–50% of their oils.
Fatty-acid profile
Tallow (beef fat) 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.
Tallow (beef fat) is about 52% saturated fat and 46% unsaturated — that saturated majority is what lets it firm up a bar and hold a stable lather.
| Fatty acid | Share | What it does in soap |
|---|---|---|
| Oleic acid | 43% | a monounsaturated fatty acid that makes a gentle, conditioning, moisturising bar with a slick, lower lather and a slower trace |
| Palmitic acid | 27% | a saturated fatty acid that builds a hard, long-lasting bar with a stable, creamy lather |
| Stearic acid | 22% | a saturated fatty acid that adds hardness and a thick, stable lather; a large share can speed up trace |
| Myristic acid | 3% | a hard, cleansing, bubbly saturated fatty acid that usually travels alongside lauric acid |
| Linoleic acid | 3% | a polyunsaturated fatty acid that is very conditioning but oxidises readily — a driver of DOS (dreaded orange spots) at high levels |
Tallow (beef fat) in the bar
Expect a dense, low-bubble, creamy lather from Tallow (beef fat) — 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, Tallow (beef fat) 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 Tallow (beef fat) 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 Tallow (beef fat)
Out of Tallow (beef fat)? 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) |
|---|---|---|---|---|
| Tallow (beef fat) (this oil) | 52 | 3 | 46 | 0.138 |
| Palm oil | 49 | 1 | 49 | 0.142 |
| Mango butter | 48 | 0 | 49 | 0.136 |
| Cupuaçu butter, deodorized | 50 | 0 | 41 | 0.135 |
| Cupuaçu butter, refined | 50 | 0 | 41 | 0.135 |
Using Tallow (beef fat) in a recipe
One gram of Tallow (beef fat) needs about 0.138 g of NaOH (sodium hydroxide) to turn fully to soap, within a documented range of 0.136–0.14 g/g across sources. The calculator below uses this value; always confirm the lye weight before you mix.
Its iodine value is about 44 — 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 Tallow (beef fat) at roughly 20–50% of their oils.
Maker's note: Hard, stable, classic long-lasting bar; historic laundry-soap base. NOT vegan.
Calculate lye for Tallow (beef fat)
The calculator below is pre-loaded with Tallow (beef fat). 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.
- Soaper's Choice — SAP Values — SAP (industry consensus)
- 7VIRIDES — Soap Making Oils Encyclopedia — SAP + fatty-acid profile
SAP data last updated · 51 oils covered.
Tallow (beef fat) soap FAQ
- Can you make soap with 100% Tallow (beef fat)?
- It is not recommended. Tallow (beef fat) shows its best in a blend, usually up to about 50% 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 Tallow (beef fat)?
- A 5% superfat is a safe, common starting point for recipes using Tallow (beef fat); 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 Tallow (beef fat) speed up or slow down trace?
- Because it is rich in palmitic and stearic acids, Tallow (beef fat) 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.