Making Glycerine Biodiesel Soap

Glycerin

Glycerin is one of the byproducts from the process by which bio-diesel is made. Biodiesel is made from vegetable oil through a chemical process as transesterification, which yields biodiesel and glycerin. Soap made from this glycerin is good for industrial purposes because it can readily clean grease. For household use, dyes and fragrances can be added to alter the color and smell. Glycerin obtained from the transesterification reaction should be filtered to remove any impurities.

Other Ingredients

Most soaps are essentially a mixture of glycerin, lye and water. Changing the amounts of lye and water can affect the properties of the soap that is produced. Adding more lye makes a stronger soap that is very good at cutting grease. However, large amounts of lye also dry out the skin. Adding extra water helps the soap generate a thicker lather. As a starting basic, one quart of water and 6 oz of lye for every gallon of glycerin is a good benchmark.

Process

The glycerin should first be heated to between 150 and 175 degrees Fahrenheit to remove any methanol and ethanol that may be contaminating it. Then, the lye should be added to the water. This mixture should be heated to 100 degrees F and then added to the heated glycerin. This mixture should be mixed slowly for about 20 minutes, after which it can be poured into a storage container for cooling. After 24 hours, the soap can be cut into bars, and allowed to cool further. After 4 to 7 days, the soap will be ready for use.