The term describes a process where soap curds pass through a roller mill, typically three times. This rigorous milling procedure refines the soap base, eliminating excess moisture and air. An example would be a bar of bath soap advertised as being particularly long-lasting and having a creamy lather due to this manufacturing technique.
This method yields a harder, denser, and more uniform soap bar. The resulting product is generally longer-lasting as it dissolves more slowly. Furthermore, soaps manufactured in this way tend to produce a richer, more luxurious lather compared to their conventionally produced counterparts. Historically, the practice arose from a desire to create a higher-quality product with improved performance characteristics.
