Formulations for cleansing bars that incorporate rendered animal fat, specifically from swine, represent a traditional approach to soapmaking. These recipes utilize the saturated fatty acids present in the rendered fat, which, when saponified with a strong alkali such as sodium hydroxide or potassium hydroxide, yield a product with specific cleansing and lathering characteristics. Examples include recipes specifying a ratio of lard to lye, often in combination with other oils, to achieve a desired hardness and lather quality in the final product.
The utilization of rendered animal fat in soap production offers several advantages. Historically, it provided an accessible and economical ingredient for soapmakers. In the context of modern formulations, rendered animal fat contributes a hardness and a stable, creamy lather to the finished bar. Its presence can also influence the moisturizing properties of the soap, depending on the overall formulation and superfatting levels. The practice of using rendered animal fat dates back centuries and reflects a resourcefulness in utilizing available materials.