Most of us grew up using commercially, mass-produced soap brands. Who knew that these products are not technically soap in the traditional sense. They are formulated as syndet bars, which stands for "synthetic detergent bars." Syndet bars are not made from the saponification of fats and oils with lye (as in the case of traditional soap); instead, they are made from synthetic surfactants and other ingredients.
Cold processed soap, also known as CP soap, is a method of making soap from scratch using lye (sodium hydroxide) and various oils or fats. The term "cold process" refers to the fact that heat is not externally applied to the soap-making mixture during saponification (the chemical reaction between lye and fats that creates soap). Instead, the chemical reaction generates its own heat.
Here's a basic overview of the cold process soap-making process:
-
Ingredients: You start by selecting a combination of oils and fats that will provide the desired properties for your soap, such as lathering, moisturizing, or hardness. Common choices include olive oil, coconut oil, palm oil, and various other vegetable and nut oils.
-
Safety Precautions: When working with lye, it's crucial to take safety precautions. This includes wearing protective gear like gloves and goggles and working in a well-ventilated area.
-
Lye Solution: The lye is dissolved in water to create a lye solution. This solution is then allowed to cool down.
-
Oils and Fats: The selected oils and fats are melted and combined in a separate container.
-
Mixing: The lye solution and the oil mixture are combined, and the mixture is stirred or blended until it reaches trace. Trace is the point at which the mixture thickens and becomes uniform, indicating that saponification is occurring.
-
Additives: At this point, fragrances, colors, and other additives can be incorporated into the soap.
-
Molding: The soap mixture is poured into molds, where it will harden and continue to saponify over the course of a few days to several weeks, depending on the specific recipe.
-
Curing: After the soap has been removed from the molds, it's left to cure for a period of time, typically around 4-6 weeks. During this time, excess moisture in the soap evaporates, resulting in a milder and harder bar of soap.
Cold processed soap-making retains the natural glycerin produced during the saponification process, which can be beneficial for the skin. It's this natural glycerin content that helps to moisturize the skin, leaving it soft and hydrated. CP soap doesn't usually contain the harsh detergents, synthetic fragrances, and preservatives that are often found in commercial soaps which reduces the risk of skin irritation or allergic reactions.