The Chemistry of Soap
Posted on Nov 3 2011 at 06:29:18 AM in Cultures & Groups
Soap needs no introduction. You and I know soap. We've grown up with soap and use it on a daily basis. Be it a bar, powder or liquid, soap is ever present in our lives and is vital as part of our body hygiene as we use it to wash our hands at the very least.
However, do you know what soap is made of? How it's produced? It's easy to take soap as granted without knowing much about it. I can't say that I ever wanted to learn what soap was as a substance, but several visits from various cleaning W4 teams inspired the curiosity in me to research the topic and find out.
From what I read on the subject I can say that natural soap is the sodium or potassium salt of a fatty acid. This refers to the soap that was made in the olden days using animal lard and tallow to create soap and is still being made in the remote and less industrialized regions. What you need to learn in order to understand soap is the term 'fatty acid'.
Fatty acids are found in nutrition such as fats and oils, a reference to the lard and tallow in question. Although we don't directly consume lard, they are still present in the chemical composition of junk food that affects our health. Acids, by rule, react with alkali, which are called bases and mixing an acid with a base is one of the easiest way to incite a chemical reaction, which is exactly what the act of saponification is.
When you combine the tallow or lard with a strong base. The base then separates the fatty acid from the fat and allows it to bind with the sodium or potassium element of the base. This new chemical compound is the salt part of the definition above, thus effectively being soap. Simple, but that's not really the case with soap anymore.
Natural fatty acids from tallow have been substituted with petroleum based products. While natural ingredients might be used for the creation of modern soap, but they undergo high energy process that alter them beyond recognition. This is why modern soap tends to dry a person's skin, whereas the natural soap makes them oily.
Thank you for reading and thank you cleaning W4 teams for the inspiration.