I found this forgotten bar of soap after winter at my home in northern Sardinia. It had grown a coat of mould (pictured). What is the mould and how did it grow on soap, which is supposed to keep your hands clean?Patrizia Figoli Turcheteti, Bellaire, Texas, UK
To quote a recent Dilbert cartoon, "There isn't a big distinction between soap and cheese."Depending on the process and the amount of lye, we basically are washing with food.
Real soap is not specifically "anti-microbial", "anti-fungal", or event "anti-bacterial". Soap is simply an emulsifier which allows lipids (like food oils, machine grease, etc) to disolve in water so that it can be washed away. In fact, it's been shown that low concentrations of soap can increase the growth of bacteria in a body of water by reducing the surface tension (possible making nutrients more available?).
Yes as has been mentioned most soaps are not antimicrobial, unless specific microbicides are added. I suspect that this mould is feeding on the skin cells and proteins from the previous people who washed with the soap! They may even have left the mould spores themselves, a nice thought!
Apart from the fact that soaps (salts of fatty acids) are NOT essentially anti-microbial and largely act as a surfactant,...... i presume there could have been a chance that the soap sitting in the winter could have developed a dry surface and may have later accumulated enough moisture to enable the growth of the mould... i do research work with fungi/yeast and i would love to take a look at the soap..:)