Soap Making 101

Soap Making 101 covers the basic concepts of the various soap making processes such as the hot process, cold process and melt & pour.

The Basics

Soap is created by a process called saponification. This process happens when fats or oil which contain fatty acids are mixed together with an alkali base (such as a lye). Soap can be made through a cold process, hot process, melt & pour or through a continuous process (commercial manufacturing). The hot process was very popular in colonial America while today many hobbyists use the cold process or melt & pour.

When oil or fats (acid) come into contact with the lye or sodium hydroxide (base) the saponification process converts the oil/fat into two substances: fatty acids and glycerin. At this point the sodium or potassium part of the alkali mixes with the fatty acid. The point at which the solution begins to thicken is called a trace. At this stage the solution can be poured into molds where it will begin to harden and eventually be ready to be used as soap.

Soap Today

The soap you buy at the store today is quite different from the one made through out history and the ones that you can make your self at home. Many of the commercial based soaps contain detergents which are made from petroleum based products and contain a very small percentage of natural and pure products.

Lye soaps have a 'creaminess' that just can't be duplicated by any of the soaps you find in stores. Lye soap is wonderful on your skin. The making of lye soap causes it to produce a large amount of natural glycerin as a by-product. This is stripped off in commercial bar soap production and sold for other commercial uses like lotions, but in homemade soaps the glycerin is left in the soap.

Hot Process

The hot process was a very popular soap making method through out history especially in colonial America. The soap is made of lye which is a liquid solution of potash as well as fat. There are three basic steps for this method of soap making:

1. Making the liquid solution of potash called lye.

The lye that was used was made by slowly pouring water over hot ashes until a brownish liquid was produced. The lye dripped into a collecting vessel and was used to mix with the fat.

2. Rendering the Fat

The fat used in soap making was taken from animals where it was rendered (The cleaning of fats is called rendering). The cleaning consists or removing all impurities contained in the fat

Animal fat, when removed from the animals during butchering, must be rendered before quality soap can be produced. This rendering removes all meat tissues that still remain in the fat sections. Fat obtained from cattle is called tallow while fat obtained from pigs is called lard. The cleaning process usually is done by boiling the fat along with water.

3. Mixing the fats and lye and boiling the solution

The last part of the hot process was done in a kettle over a fire where the solutions were combined and mixed. This boiling process could take up to six to eight hours depending on the amount of the mixture and the strength of the lye.

Cold Process

The process that more advanced hobbyists and small business owners use is called cold process soap making or CP. Even though it is called a cold process, the various mixtures are boiled in a pot. Heat is also derived from the reaction of water and lye mixing and their incorporation into the oil or fat. This is evident when the lye is poured into the water as it heats up the water immediately. This process basically relies on the proper ratios of the lye (sodium hydroxide) and water to fatty acids that form a chemical reaction known as saponifaction. During saponification, the oils/fat and lye mix and become soap.

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). The soaps made by this process are a lot gentler to the skin, have a nicer scent and are of better quality then the ones discussed in the hot process section but are more difficult and time consuming than the ones done via the melt & pour process.

The equipment needed for this process includes many items that can be found in most kitchens such as pots for boiling, containers for the mixing, a scale, a thermometer and safety equipment such as goggles and gloves which should be worn during this process!

Soap molds are also needed in order to provide shape for your soap. There are many different shapes of molds that produce very interesting designs. Make sure you use molds that are good quality and are resistant to high temperatures.

You will also need fat or oil and lye for hardening. Various fats or oils may be used such as beef fat, lard, tallow, palm oil, olive oil, coconut oil, cocoa butter or shortenings. If using fat it may need to be cleaned (rendered) unless you purchase ready made tallow. Other wise it will have to be melted to filter out the impurities. In order to achieve a desired scent or color you will also require special dyes for coloring and fragrant oil or essential oils for the scent. These ingredients are also available on our site.

The next step involved is boiling and mixing the various ingredients (water and lye) with the fat or oil, scents and coloring. Once this is done the mixture is added to a mold and cured for at least 2 weeks.

Melt & Pour Process

Melt & Pour soap making is the easiest of all the methods and is by far the least time consuming. It is intended for hobbyist, casual or first time soap makers and even children. The time is saved by avoiding the curing process (which can take 6-8 weeks) that comes in making soap via the cold process in which glycerin is produced. 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.

By purchasing premade glycerin soap blocks such as Stephenson soap bases from a distributor you can save a lot of time and hassle. They are usually available in either opaque or transparent blocks.

These glycerin soap blocks can be easily melted in a microwave. Once melted you can mix in your scent (essential oil or fragrant oil), dye (color), and any other additives you wish such as botanical extracts, raw materials or butters. It is recommended though that all your additives do not exceed 2% of the entire soap solution.

You may even insert objects inside the soap if you feel extra creative such as:

• Photographs or business cards (with a plastic coating)
• Small toys
• Small pearls or sea shells
• Mini silk flowers (such as roses)
• Dried herbs or leaves (do not use flowers as they tend to discolor high heat)
• Ultra-fine cosmetic-grade prisma glitter
• Whole coffee beans (and instant coffee for added color)

The solution is then mixed and poured into soap molds and within about 12-24 hours the soap is ready for use. You may place them in a freezer to solidify them quicker.

For a much more detailed analysis of a melt & pour soap making project see our recipe section