Glycerine may be used for other purposes and is therefore separated from the soap mixture. The soap, by this time forms a curd. It is boiled again, in order to remove all traces of salt. After this, the soap is given the colour and perfume. It is then left as long bars to cool and later cut and wrapped for the commercial market.
Detergents are materials that aid in the removal of dirt or other matter from contaminated surfaces.
Until the 1940s, soap was the only important detergent. This led the soap manufacturers to look for soapless or synthetic detergents. Today soap is one of many detergent products. Detergents contain comparatively large molecules. One part of the molecule is soluble in organic material, and the other part is soluble in water.