Unlike other soap-making methods that involve external heat sources, cold process soap relies on the heat generated during the saponification process, where oils and lye react to form soap. This method allows for more control over ingredients, making it suitable for incorporating a variety of oils and additives with specific skincare benefits. Cold process soap often retains more glycerin, a natural moisturizer, compared to some commercial soaps. Additionally, it allows soap makers to create unique designs and customize formulations to cater to various skin types or specific needs. The curing time required contributes to a harder, longer-lasting bar of soap.

Charcoal in cold process soap can serve multiple purposes. Activated charcoal is often used for its ability to absorb impurities and toxins from the skin, making it beneficial for those with oily or acne-prone skin. It can help detoxify the skin by drawing out excess oil and impurities.

Cold process soap is made through a saponification reaction between oils and sodium hydroxide (lye), creating a solid bar made from natural ingredients, like olive oil, coconut oil, shea butter, cocoa buter, etc. Upon saponification, no lye remains in the soap. Body wash, on the other hand, is a liquid cleanser typically formulated with synthetic detergents.