Soap Making Methods

There are many ways to make soap. When people talk about the soap “Grandma used to make,” they’re not talking about the pretty and colorful creations you see lining the windows of upscale salons and boutiques today. This article will discuss the basic types of soap; it is not meant to be a “How To” article on making soap. There are some great books, such as “The Soapmakers Companion” by Susan Miller Cavitch.

Melt and Pour Soap

Technically, all hand made soap is “Glycerin Soap.” In many commercial soaps, all the extra glycerin (formed naturally by the cold process soapmaking method) is harvested out. Thus, all handmade soap is glycerin rich (since hand made soapmakers don’t harvest out glycerin in their soap).

In today’s market, the term “Glycerin Soap” is commonly used to refer to clear soap. Generally, the clear soap has extra glycerin added to it to produce a very nourishing, moisturizing bar. Glycerin is a “humectant.” It draws moisture to itself; the theory is that if you wash with glycerin soap, a thin layer of glycerin will remain, drawing moisture to your skin.

Clear soap base can be purchased in large blocks to be melted down, colored and fragranced, and placed into molds (or used to make loaves of soap to be sliced). This type of soap is called “Melt and Pour” and the artistry of melt and pour is called “Soap Casting.” Melt and Pour soap making is gaining in popularity because of its ease of use. There are no significant safety measures (other than basic common sense – don’t put your hand in the hot soap, don’t cut your finger off with the knife etc…) needed for soapcasting. Children can do it. It’s a great outlet for creative types.

You can also make clear soap from scratch. This method involves all the aspects of cold process soapmaking, but takes it a few steps further by adding alcohol for clarity and a glycerin and sugar mix to suspend and enhance the clarity. It is a dangerous process because of the alcohol vapors. If you wish to make clear soap (which will not melt down like melt and pour – it’s one pour only soap), please read “Making Transparent Soap” by Catherine Failor. This is an excellent resource for anyone wishing to make clear soap from scratch.

View our Melt and Pour Soap making tutorial.

Cold Process Soap

The type of soap Grandma made is called “Cold Process” soap (commonly referred to as “CP” soap). It is made by combining fatty acids 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.

Cold process soapmaking requires the use of lye 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).

View some easy Cold Process Soap recipes.

Hot Process Soaps

There are variations on the cold process method. Hot process soap is an interesting take on the cold process method. The simple explanation is that you take all your ingredients, and add them to a pot (that is then placed over a heat source, such as a stove) and stir frequently until the soap goes through various stages. The excess water is evaporated off and the soap is ready to use once cooled. For more information on Hot Process soap making, there are some interesting articles in The Saponifier and on Melanie Dunstan’s website.

Rebatching Soaps

Rebatching, also called French milled, or Triple milled soap, is another form of cold process soapmaking. You make your cold process soap from scratch, grate it up, place it over a heat source, in a kettle, with a little liquid (water works very well), and the mixture melts down into a mushy mess that you add colorant and fragrance too. This method is often used to preserve the scent or the healing properties of some essential oils.