We have been very lucky here to host Isa from Brazil who taught us and our PDC students how to make basic laundry-type soap from used cooking oil.
Used oil (cooking oil) is not easily disposable. You can compost it with lots of wood chips. I suppose you can give it to your chooks in small amount, and pigs perhaps. You can burn it in your converted diesel car, truck or tractor but that requires very large quantities.
So in reality, we don’t quite know what to do with it.
(There is always the option to burn that in oil candles but realistically, who does that anymore?)
Permaculture principle to Create no Waste is fully demonstrated in soap making as we transform a waste product into a useful product.
I’d like to share Isa’s recipe and process below.
I will share her recipe of cosmetic-type soap -Castille Soap- in a future post, and this one uses olive oil, clean, pure, un-used olive oil.
- 3kg used cooking oil (we used food-grade linseed oil which edibility had expired)
- 900gr cold water
- 408gr caustic soda (sodium hydroxide, minimum of purity 97%).
- Stick blender
- A (plastic, or glass, or stainless steel) bowl to measure liquids
- A (plastic, or glass, or stainless steel) bowl to mix the liquids
- A kitchen scale
- A piece of clean pantyhose, to separate solid particles from the oil
- A plastic spatula or a plastic spoon
For your safety, please wear:
- protective goggles
- protective gloves
- a mask
- an apron
- closed shoes
- Do note make the mixture inside the house (with doors and windows closed).
- Do not mix with children and pets around.
- Do not use aluminum utensils.
How to make:
- Separate the solid particles from the used oil using the pantyhose.
- Place the oil in a plastic bowl.
- In another container place the cold water, then add the soda (not the other way around – danger!).
- Dissolve the soda in the water thoroughly and wait about five minutes. This becomes lye water.
- Add the lye water to the oil.
- Then blend with the stick blender, for about three minute or until the consistency of the mixture looks like jam (or mango purée!).
- Put this mixture into a mold, which can be made of plastic, wood or silicon, but never use aluminum!.
- Let the mixture turns into the soap in a place with constant temperature.
- After one or two days (depending on the weather) you can cut the soap.
- Cure these pieces of soap for, at least, four weeks before using them.
Thank you Isa for teaching us your skills! See you soon!