Why 'Real' Soaps Don't Require Preservatives

 hi all.

Today's question from a reader was that why soaps that are handmade using lye and carrier oils like coconut, olive etc; made using the cold process or hot process method doesn't need preservatives.

If you have read my previous post on preservatives and why we need it in products that has 'water' you would realise that most of them will need preservatives.

You see; very long ago; in this world we live in; scientist came to realise that besides us; there were many other 'living' things in the air; and that includes bacteria, fungus, and virus (thanks to coronavirus you cant say its made up anymore; yes it is airborne!)

so anyways; just like all other living things (virus excluded as it only activates when its on a host); but bacteria and fungus; it needs to live in a comfortable conditions. That includes having nice weather (temperature), having nice food (nutritions), having nice condition (pH), and having air to breathe (water H2O=oxygen).

so this would mean; in order for the microbes to live; it would need all the conditions met so that they can live happily and reproduce (beranak) as much as possible.

To get this; they will need the temperature to be at 20-30 degrees Celsius (thats our 'room temperature' in Malaysia), Nutritions met (thats usually from extracts and all the other extra vitamins we put into our products), pH between 6-7.5, and having water (or water like ingredients like hydrosols, liquid extracts etc) to give it oxygen to breathe. 

Now because of this too; remember that microbes cant live in a 100% oil products (like balm/ Face Oil); because oils would inhibit oxygens; causing microbes to suffocate and die. (similar to metals if we didn't want it to rust; we put oil so that it doesn't get oxygen from air to rust).

So now back to the soaps.

If you notice; most soaps that are handmade uses lye (sodium hydroxide/ potassium hydroxide).

These soaps have high pH (remember school form 4 the one with pH 9 is usually soaps; the olden day soaps not those surfactant 'soap-free' soaps we have nowdays).

and so because it has high pH; we dont need preservatives. Simply because its not a favorable condition for the microbes to live. They will practically die in the war zone against these not nice condition to live in.

and so because of that; you dont need to add preservatives to your 'real' soap.

Nisha.