Just what is soap?
There are a few different ways to make soap and different types. These are the ones you might have heard of
- Cold process soap
- Melt and Pour Soap
When people first start making or even buying soap, they tend to encounter melt and pour. These are blocks of stuff that you literally “melt and pour”. You cut off a chunk, melt it in a microwave or over a heat source, add fragrance and colours if required and pour into moulds.
You can make the “see through” type glycerine soaps or the more opaque types. This type of “soap” also lends itself well to the industrial process for large scale manufacturing. Nothing wrong with it, but it’s not the same as cold process or hot process soap making.
Cold process soap is making real soap from scratch with a batch of ingredients which are usually hard fats; either from plants or animals and liquid oils and you can control exactly what goes into them and tweak your recipe as you wish. Here at Bewitched Botanicals Soap Co we only use plant based fats and oils.
How is soap formed and what happens during the curing process?
When you mix fats/butters and oils which are also known as triglycerides with sodium hydroxide they break down in to their core components namely glycerine and fatty acids. Depending on your choice of butters and oils some will be short chain fatty acids and some will be longer chain fatty acids - more about that in a moment. The chemical formula of sodium hydroxide is NaOH. Na is Sodium and Hydroxide is OH. Hang onto the OH for a bit….
Fatty acids combine with the OH (hydroxide) to create sodium salts also known as soap but the process is not complete at this stage. The sodium salts need to further align themselves into complex structures called soap crystals.
Whilst the soap batter is still liquid, short chain fatty acids begin to form into salt crystals together with some of the longer chain fatty acids. Saponification is complete within around 48 hours, ie all the hydroxide has been turned in to sodium salts but during the continuing cure time the longer chain fatty acids are still busy queuing to rearrange themselves into soap crystals and this is what helps soap to become harder as time goes on not just the water evaporation which mostly occurs within the first 2 weeks. The by-product of this combination by the way is glycerine, that sticky gloopy moisturising substance and that stays in the soap. Industrial manufacturers often remove it.
If you use soap before it has fully cured it will dissolve more quickly not just because it has a higher water content but because not all of the longer chain fatty acids have formed soap crystals at that point and it is the crystalline component of soap that is predominantly made up of longer chain fats which gives hardness and durability.
So, at this stage it is best to leave the soap to cure, which basically means that the process can continue, and the water can evaporate, and the soap bar can harden. As it does this it becomes even more moisturising.
We at Bewitched Botanicals Soap Co make good old fashioned Cold Process Soap, which is why when we run out it can take up to a month for us to have the next batch ready. And, you never know how much to make as different fragrances sell out at different times of the year, even our best sellers !
Don’t let the chemistry scare you off! Chemistry is life, our bodies are made up of a myriad of chemicals, so is our food and life itself. Stay tuned and in another blog post we will discuss terms such as “Natural” & “Organic” and what it means and what folk think it means !