Many people are awesome in Australia, these awesome people also make biodiesel from used cooking oil. I am also an awesome person and I make soap from used cooking oil. The ingredients are actually the same, except for one key ingredient, this key ingredient is either water or methanol (alcohol).
To make soap the ingredients are:
oil, lye and water.
To make biodiesel the ingredients are:
oil, lye, methanol (alcohol).
We have a challenge in the Western world, and that is to make use of material that would be discarded into land fill or worse still, poured down the drains. I believe that as a society we have a responsibility to re-purpose this material. There is so much used cooking oil to save even just locally and we don’t have enough room to store it.
Many soap makers use new oil that they purchase. Whilst I combine some new oil - that of coconut oil, shea butter, and cocoa butter, I predominantly use re-purposed vegetable oil once used for cooking, as a base for my Simple Soap, Sharp Shave, Manly Mate and Grunt Work. In this way the product is carbon neutral because it is made from oil that has already been manufactured and used for cooking.
I use reclaimed vegetable oil that I source from my local cafes and restaurants – which means it is rescued from ending up in landfill, or worse, poured down the drain! Sourcing the oil in this way means it is carbon neutral, is good waste management, is recycling a product and contributes to my local circular economy. The Soap i make is 100% safe and I PH test every batch ensuring a PH of 9 or lower is maintained.
I filter the oil through a sieve and cheese cloth several times. I then boil the oil with a mixture of water, let it cool then separate the oil off the top. Cleaning the oil and making soap in this way ensures it is 100% completely safe. You will be surprised at the texture, lather and lusciousness of the soap.
When I make the soap, I use the cold process soap method and I ensure there is a very minimal superfat ratio. This means that ALL the oil has been transformed (saponified) into soap, with no remaining remnants of oil.
I would love it if more awesome Australians and other awesome people around the world would use left over cooking oil to make soap. Watch a video here - demonstrating how i filter the cooking oil before using it to make soap.