What is Cold Process Soap?

Soap has been a vital part of human civilization for thousands of years. From ancient cultures to modern times, soap making techniques have evolved with different methods yielding varying results. One of the most traditional and highly regarded methods is “cold process” soap making. In this article, we’ll explore what cold process soap is and compare it to other soap making methods like “hot process” and contemporary “melt-and-pour”.

Cold process soap is made through the traditional method of combining oils or fats with an alkali, such as lye, in a chemical reaction called “saponification”. As the saponification reaction takes place, heat is generated by the breaking down of fats which then helps the chemical reaction continue as the soap cures. What makes cold process soap unique is that it involves mixing these ingredients at room temperature without using additional heat and only relies on the heat produced by the chemical reaction itself. Because of this, the final stages of the saponification reaction take place over multiple weeks as the soap gradually cures. The slow curing process allows the soap to be mild and hydrating, making it ideal for those with sensitive skin or specific skincare needs. Cold process soap also retains more of the natural glycerin produced during saponification, which helps to moisturize the skin, as excess heat can cause larger amounts of this glycerin to evaporate from the soap.

Hot process soap making is another popular method, with one key difference being the use of heat to speed up the saponification process. In hot process soap making, after the oils and lye are combined the mixture is heated to accelerate the reaction. This results in a much faster saponification, which allows the soap to be used within a few days rather than weeks. Although one of the main advantages of hot process soap is that it can be used much sooner than cold process soap, many enthusiasts and soap makers still prefer the traditional cold process due to its gentleness and the fact that it allows for a greater preservation of the oils’ properties. This is especially important for soaps that are made entirely from natural ingredients as these materials tend to be more sensitive to degradation from heat than their synthetic counterparts.

Melt-and-pour soap is a somewhat separate method from both cold and hot process soap making. It involves purchasing pre-made soap bases that are melted down, mixed with additives, and poured into molds. This method is quick and doesn’t require handling lye as this part of the soap making process has already been done by someone else, making it ideal for beginners or those looking for a more straightforward approach to soap crafting. While melt-and-pour soap is convenient and easy to use, it often lacks the rich natural properties that cold process soap boasts, both because of its dependence on heat and the frequency with which melt-and-pour soap bases are made from undesirable ingredients like synthetic additives, detergents, and preservatives.

Cold process soap remains one of the most beloved and traditional methods of soap making, offering a high quality result. While it requires more time and patience compared to faster methods like hot process and melt-and-pour soap, the product is typically much more gentle and moisturizing. For those who appreciate the art of soap making and seek a natural product, cold process soap stands as the gold standard in the world of handcrafted soap.