Tallow is a hard, white rendered fat traditionally obtained from cows and sheep, although it may also be derived other animals such as deer (Pig fat, however, is known as lard). Among other things it is used in the production of soap, candles and as lubricant. It is one of the main ingredients in many shaving soaps. It is often listed in its saponified form as potassium tallowate or sodium tallowate.
Chemical Composition
Tallow is in actuality not a single type of fatty acid, but rather a mixture of various fatty acids. The composition of tallow typically includes stearic acid, palmitic acid, myristic acid, oleic acid, linoleic acid, and alpha-linolenic acid, all of which are saponifiable. The major constituents are oleic acid, palmitic acid, and stearic acid, in that order. Interestingly, oleic and palmitic acid are also the major constituents of palm oil, another oil widely used in the production of shaving soaps.
Tallow as a source of glycerin
It is a common misperception that tallow-based soaps do not contain glycerin. Glycerin is a byproduct of the saponification (soap-making) process, and soap derived from tallow is no exception.
Many of the fatty acids in tallow are triglycerides, which are molecules composed of three fatty acid chains chemically bonded to a single glycerol, as it's more commonly known glycerin, head. During saponification, the three fatty acid chains react with a strong base, such as sodium hydroxide or potassium hydroxide, resulting in soap. At the same time, the reaction produces glycerin at the rate of three soap molecules to every one glycerin molecule. The glycerin then can either remain in the soap, or the glycerin may be removed by distillation and sold for use in other industries.
Many of the fatty acids in tallow are triglycerides, which are molecules composed of three fatty acid chains chemically bonded to a single glycerol, as it's more commonly known glycerin, head. During saponification, the three fatty acid chains react with a strong base, such as sodium hydroxide or potassium hydroxide, resulting in soap. At the same time, the reaction produces glycerin at the rate of three soap molecules to every one glycerin molecule. The glycerin then can either remain in the soap, or the glycerin may be removed by distillation and sold for use in other industries.
Tallow vs. Non-tallow Soaps
A common source of debate among wet shavers is the inclusion or exclusion of tallow in shaving soaps. Many feel that the inclusion of tallow as a source of saponifiable fatty acids is essential to producing a superior shaving soap. However, it is worth noting that the fatty acid composition is similar to that of palm oil. Furthermore, palm oil is commonly blended with various oils, most commonly palm kernel oil, to produce oil blends that closely mirror the fatty acid composition of tallow. Such blends are widely used in the production of commercial soaps, and often in soaps reformulated to avoid the use of animal products.
Tallow soaps vs. Microwave
Tallow cannot be melted in a microwave. The most efficient procedure to transfer a tallow soap into a smaller/different container is to grate it. Follow this link to know how to mill any soap into a container.