A cold process soap is made when you mix fixed oils like coconut oil, olive or palm oil with an alkali which can be lye or sodium hydroxide to create a bar of soap, this chemical process is called as Saponification. You have complete control over the ingredients for making this type of soap. If you judiciously use the ingredients then you can extract a long lasting bar of soap.
Making your own cold process soap is wiser than buying the commercial soaps. You are well aware of all the ingredients used in your hand made cold process soap which would be completely healthy for you. In commercial soap there is always uncertainty about the ingredients used. There maybe chemicals used in commercial soap which can be harmful for your skin. It’s better to learn making soap at home which would be healthy for your skin than risk using commercial soaps.