If you have ever produced a liquid soap before, but looks cloudy; then this post it for you. In this post, I will be shearing with you an old age secret to make your liquid soap crystal clear. But before then, you need to understand the common solvents used in Liquid soap.
Liquid Soap Solvents
These solvents alcohol, glycerin, and sugar are what enable a soapmaker to transform opaque bar soap into transparent soap. The solvents literally dissolve the soap crystals and then hold them in suspension, allowing the light to pass through.
Solvents are very useful in liquid soap-making. The soap can be dissolved and cooked in alcohol, and small additions of alcohol, glycerin, and sugar will improve the brightness and clarity of the finished liquid.
Alcohols are solvents. In liquid soapmaking, solvents can speed saponification as well as lower a liquid’s cloud point, or the point at which insoluble substances precipitate out of solution. When liquid soaps are slightly cloudy because of excess fatty acids or minerals, a small addition of alcohol often clarifies the solution. Excess alcohol, however, reduces the foaming action of the soap.
The liquid soapmaker has a choice of two types of alcohol: ethanol or isopropyl alcohol.
Note: Alcohol, glycerin, and sugar lower the cloud point of liquid soap, helping create crystal clarity.
Ethanol: Colorless and odorless, ethanol is produced from the fermentation of sugar, starch, and other carbohydrates. Scientific supply houses sell denatured ethanol in gallon containers a much cheaper option than pure liquor store ethanol. When ordering denatured alcohol, be sure to specify SDA (specially denatured alcohol) 3A or SDA3C, two cosmetic grades approved by the FDA. Both have been denatured with trace amounts of isopropyl alcohol and methanol.
Isopropyl alcohol: Common isopropyl alcohol, or rubbing alcohol, can also be used for liquid soapmaking. As a solvent, it’s weaker than ethanol, but because potassium soaps are so soluble, this weakness isn’t a handicap. The strong odor of isopropyl alcohol can potentially taint the finished liquid, but this problem is easily rectified by evaporating the alcohol out of solution at the end of the soapmaking process.
All drugstores carry isopropyl alcohol, usually at a 70 percent strength (the remaining 30 percent is water). For the purposes of liquid soapmaking, stronger concentrations, in the range of 90 to 99 percent, are desirable. Many pharmacies stock the stronger solutions on the shelf, and some will special-order 99 percent concentrations; otherwise, contact the nearest scientific supply house.
A natural by-product of saponification, glycerin is technically an alcohol. Added to finished liquid soap, it lowers the cloud point the same way alcohol does, helping clarify residual milkiness. In addition, it functions as a humectant, drawing moisture from the air and holding it to the skin. Like ethanol or isopropyl alcohol, excessive amounts of glycerin dampen the foaming action of soap, though small amounts actually boost the foam.
Other Key Ingredients Used To Make A Clear Liquid Soap
Small percentages of sugar solution added to liquid soaps help dissipate cloudiness. Ounce for ounce, sugar is a more effective clarifier than glycerin, though it lacks glycerin s moisturizing properties.
Soft or Distilled Water
Minerals in hard water react with fatty acids to form insoluble fatty acid salts. The result? Cloudiness, much like the cloudiness formed by insoluble palmitic and stearic acid soaps mentioned earlier. For this reason, the use of soft or distilled water is essential for all phases of liquid soap production.
Pears, the very first transparent soap, was formulated with rosin. Distilled from the oleoresin of pine trees, rosin saponifies much like an oil, but without any resulting glycerin. It imparts clarity to soap and a smooth cold-cream finish to the lather. It also acts as a detergent and preservative. Sold as fragrant, amber-colored crystals, rosin can be purchased through the suppliers listed in Resources.
Borax, or Sodium Borate
Borax is one of the best all-around additives for liquid soaps, possessing many desirable qualities. It s a viscosity modifier (thickener), an emulsifier, a water softener, a moisturizer, a foam booster and stabilizer, a pH buffer, and a preservative. Pharmacies carry borax (often behind the counter, so ask if it s not on the shelf), or it can be obtained from the suppliers listed in Resources.
Like borax, Calgon brand bath preparation enhances foaming, softens hard water, and triggers gelling in liquid soaps. Calgon is a blend of various sodium salts, mainly sodium carbonate and sodium hexametaphosphate. Buy the nonfoaming bath variety. One drawback of Calgon is that the finished soap turns blue because of the dye in the powder.
Potassium soap bases are quite sticky and viscous; stirring them is almost as difficult as stirring hot tar. One additive used by old-time liquid soapmakers to loosen the soap was potassium carbonate, or pearl ash. Pearl ash is a salt of potassium. When it is added to a potassium paste, the molecules of the carbonate actually insert themselves between the molecules of potassium hydroxide, making the soap much more pliable. Potassium carbonate is an optional ingredient, but if you’d like to experiment with it, purchase it through any scientific supply house.
Note: Rosin, which is readily available from soapmaking suppliers, enhances the clarity and texture of liquid soap.
Liquid Soap Preservatives
The most effective preservative for liquid soap is complete saponification. Oxygenated fats trigger rancidity. Because oxygen attaches most readily to free fatty acids, it follows that thoroughly neutralized soap offers no oxidation sites. Fresh, clean-smelling soft oils are also very important because soft oils are by their very nature unsaturated and are more receptive to oxygen than saturated fats such as coconut oil and palm oil. A completely saponified rancid oil will produce a rancid-smelling soap. No amount of cooking reverses preexisting rancidity.
Many additives in liquid soap such as borax, glycerin, alcohol, rosin, and citric acid also act as preservatives. Certain essential oils, such as clary sage, also have preservative properties.
If you wish to use preservatives, use a mixed-tocopherol vitamin E. Vitamin E is composed of many types of tocopherols, such as alpha, gamma, and omega. The alpha tocopherols are effective for healing skin but not for preserving soaps. If you specifically purchase mixed-tocopherol vitamin E, you’re getting the optimum preservative in vitamin E form.
Many soapmakers use grapefruit seed oil for its supposed preservative properties, but grapefruit seed oil functions as an antifungal and antibacterial agent, not as an antioxidant.