Soapmaking Soap is a surfactant, which acts as a link between water and dirt particles, decreasing surface tension in order to attract away dirt. Its beginning can be traced as far back as 2500 BC, where it is mentioned on Sumerian clay tablets, describing the use of soap to wash wool. Before that, plants with surfactant properties, such as yucca, soapwort, and horsetail, were used for bathing, and washing laundry. During the Roman Era, bathing was considered popular, even luxurious, a pastime whose popularity coincided with the building of the Roman baths in 467 AD. However, with the downfall of the Roman Empire, so came a decline in bathin