Types of Handcrafted Soap
There are many types of handcrafted soaps, all created using different methods. The chemical reaction that creates the final product, however, is always the same. Called saponification, it occurs when fatty acids react with an alkali.
Handcrafted soap can be made from scratch by a cold or hot process, or the soapmaker might chose a ready-made soap base. Regardless of method, the Handcrafted Soap & Cosmetic Guild recognizes any soap as handcrafted if it is created by these methods and at least 50% of the process, from mixing ingredients to final packaging, is done by hand.
While handcrafted soap comes in a variety of shapes and sizes, soap starts as a liquid and is often poured into a mold to harden. The mold determines the final bar shape, whether poured into individual molds or into a “loaf” or "bar" mold, which is later sliced into bars.
Types of soap include:
The method most used by those preparing soap from scratch. It is called "cold process” because no additional heat is added during the soapmaking process. However, the process itself does generate heat.
Soaps produced via the cold process method are opaque and usually have a creamy feel to the bar. Without any additives that change the color, the soap ranges from white to creamy-tan, depending on the oils used in making the soap.
The feel of the lather varies, also dependent upon the oils used to make the soap. The lather can range from tiny, very slippery, long-lasting bubbles (as with pure olive oil soap), to big, fluffy, short-lived bubbles (as with pure coconut oil soap).
The hardness of the bar is determined by the selection of oils, the amount of water used and how long the soap was dried. Cold process soaps will continue to get harder as they age because additional water evaporates out of the soap.
Most cold process soaps are made with a combination of oils, in a recipe developed by the soapmaker to create a good lather and hard bar, as well as to provide benefits with additional ingredients.
Hot Process Soap
Additional heat is applied to the soap mixture during the hot process method. The chemical reaction is the same but occurs much faster than cold process and the heat typically generates a more “rustic appearance”. Hardness depends oils, amount of water used, and time allowed for water evaporation.
As with cold process, hot process soap is opaque and ranges from white to creamy-tan depending on the oils used, although clear or transparent soaps can be produced (see below). The type and quality of the lather and other benefits of the soap are determined by the oils and other ingredients selected chosen for the recipe.
Typically made using the hot process method, liquid soap is created using a different type of lye (potassium hydroxide instead of sodium hydroxide) with more water added. Usually off-white to amber in color, depending on the oils used, most liquid soaps are clear or mostly clear.
*Important: Commercial products labeled "liquid soap" or "soft soap" are not truly soap. They are made with synthetic detergents – not the saponification process, explained above.
Also made using the hot process method, transparent soap includes additional ingredients and steps to make the soap clear. While some highly skilled soapmakers can produce transparent soap from scratch, most rely on a natural, ready-made base to create this type of soap.
A by-product of saponification (the chemical reaction of soapmaking), glycerin is typically removed during commercial soapmaking. It is then purified and sold for use in other uses including food, cosmetics, industrial production, and explosive manufacturing.
Because removing glycerin from soap is complex, requiring special equipment and skill, handcrafted soaps made from scratch retains glycerin and all its beneficial properties. Technically, it is all "glycerin soap." When most people use the term "glycerin soap" they are typically referring to transparent soap.
Ready-Made Soap Bases
Rather than make soap from scratch, some artisans choose to purchase ready-made soap bases which they melt into liquid form, adding unique color, scent, or other ingredients before pouring into molds.
Using a ready-made soap base makes it easier for the handcrafter to craft more complex and unique shapes and colors. This is because the chemical reaction to create soap has already occurred. Many of the most artistic handcrafted soap products can only be achieved using ready-made soap base.
While some ready-made soap bases are "true soap" (made via chemical reaction explained above) others contain synthetic detergent as part of all ingredients. While still considered handcrafted, these soaps do not have the same food-quality ingredients.