The cold process is very similar to the hot process, except that the mixture is not heated throughout the entire stirring process; the fat is heated, but the lye, water, and fat mixture is not heated. Some people claim that the cold process produces a soap that is softer on skin.
Both the cold and the hot process rely on lye, which is a very dangerous chemical that can burn skin on contact and is fatal if ingested. Therefore, people who use lye to make soap need to be very careful and follow detailed directions. Many people have tried to find a way to make soap without using lye, but this is impossible. Even the soap in the melt and pour soap kits was processed with lye, although people using these kits do not have to handle the lye themselves.
Children, beginners, and people who have a healthy fear of caustic chemicals are probably better off using the melt and pour method. Traditionalists might prefer the hot process, which is the oldest method that humans have used to make soap. And people who want to pamper themselves with extra conditioning soap might like the cold process.
The type of soap my Great-Grandma made is called “Cold Process” soap (commonly referred to as “CP” soap). It is made by combining fatty acids (oils) and sodium hydroxide (lye) together. Fatty acids can be almost any oil – from beef tallow to olive oil to hemp oil. The combinations for making your own personal recipe are endless.
Cold process soapmaking is a combinations of an art and science. The condensed version of this type of soapmaking is that there is a certain proportion of lye (sodium hydroxide) and water to fatty acids that forms a chemical reaction called “saponifaction.” During saponification, the oils and lye mix and become soap – the process takes approximately six weeks to fully complete. Soap has to harden and dry before it can safely be used.
Cold process soapmaking requires the use of lye (you can’t buy it just anywhere anymore) and the use of safety equipment, such as goggles and gloves. Please do not attempt to make cold process soap without researching the method thoroughly. Cold process soap is known for its hard, long lasting quality. Depending on the oils used, the bar can have great lather (coconut oil has excellent lathering properties), be incredibly mild (olive oil is renowned for its gentle qualities) or be very moisturizing (with the addition of oils, such as shea and cocoa butter or hemp oil)
From Soap Making for Beginners
Want to know what the laws are concerning soap? FDA: http://www.fda.gov/Cosmetics/ProductsIngredients/Products/ucm115449.htm
The Handcraf ted Soap and Cosmetic Guild Trade Association http://www.soapguild.org/ Another resource for soaper’s Find a member in your part of the Country, Your favorite soaper may be a member
The National Association of Women Business Owners http://nawbo.org/