If you have read a soap label and found the words sodium tallowate, you have found tallow. Not raw tallow. Tallow after it has become soap.
Start with the fat
Tallow is rendered beef fat. Like other fats, it is made mostly of triglycerides: three fatty acids joined to a backbone of glycerol. Tallow's fatty acids are mainly stearic, palmitic and oleic acid.
Add the alkali
To make bar soap, the fat is combined with sodium hydroxide, the alkali soapmakers call lye. The reaction is called saponification. It splits each triglyceride apart.
The fatty acids pair with sodium. Those sodium salts of fatty acids are soap. The glycerol backbone is released as glycerin.
When the fat is tallow, the soap that forms is called sodium tallowate.
So what is in the finished bar?
The finished bar contains sodium tallowate, water and glycerin. Sodium tallowate is the soap itself, and the reaction produces glycerin. When soap is made properly, no lye remains in the finished product. The FDA says the same in its frequently asked questions on soap.
The FDA’s soap definition has three conditions: a product composed mainly of alkali salts of fatty acids, cleaning through those salts, and marketed only as soap. Sodium tallowate identifies the soap made from tallow, but its name alone does not establish all three conditions.
Why Tallow Soap’s formulation says grass-fed beef tallow
The starting fat and the finished soap have different names. Grass-fed beef tallow names the fat. Sodium tallowate names the soap it becomes. A description of the starting fat is not a full finished-product ingredient declaration.
Tallow Soap uses one soapmaking fat: grass-fed beef tallow. That is what the brand’s one-ingredient position means. One fat. No coconut, no palm, no seed oils, no fragrance, no preservatives. Issue 25 covers what that leaves out.
Why the name matters when you read labels
Sodium tallowate tells you the soap was made from tallow. On a label with a long list, look at what else is there. If it sits beside other soaps, such as those made from other oils, the bar is a blend. If synthetic detergents contribute to cleaning, the product does not meet that part of the FDA’s soap definition.
Read the ingredients and the intended-use claims together.