I have been asked by a friend on the Simple Savings forum to explain how I make my cold processed soap. Since a picture tells a thousand words though, I have decided to let the pictures (mostly) speak for me. Hopefully this helps some people on their foray into soap making. I have made an orange coloured and mango scented soap as requested by my son Harley. Orange is his favourite colour and he had great fun helping me prepared the mould and also taking some photos. Here goes.
Here are the ingredients I used. The caustic soda is also referred to as lye and is the chemical that causes the saponification reaction to turn these different ingredients into soap. I originally learnt to make soap from following a tutorial on the Down to Earth blog at http://down---to---earth.blogspot.com There is a link there to a fantastic lye calculator that I used to create my own recipe. I have learnt through experience and research that you need at least a 50/50 ratio of oils that are solid at room temperature to those that are a liquid at room temperature.
500g vegetable oil
250g rice bran oil
500g solidified oil (animal fat)
250g copha (coconut oil)
217g caustic soda
Here comes the process.
I keep all of these bowls, utensils and various other items specifically for soap making. They have all come into contact with the caustic soda mixture and are therefore unsafe to use for food preparation. I also have a stick blender that I will use later and is kept solely for soap making.
I then cut the solidified oil and copha into cubes so that it will melt quicker. This is then put to one side while I mix the caustic soda into the water.
This photo shows the safety precautions I have taken. I have put several layers of newspapers down to protect my benchtop. I also have a cheap pair of rubber gloves as they cover my wrists and forearms as well as my hands. I also have a bottle of rain water as it is best to use either rain water, distilled water or water that has been left sitting for at least 24 hours so the chlorine in the water can evaporate off. I like to measure my water so I get the full 570g.
Here I have my oils at the back of the stove as I will heat them last. I chose to use my stove for the caustic soda stage as I turn my rangehood onto high which sucks the fumes out and I don't breathe it in. I have measured out the 570g of cold water into my glass bowl. I have my 217g of caustic soda in the little purple bowl. Always pour the caustic soda into the water. If you reverse the process, you with have an explosion on your hands.
Here is the caustic soda mix just after I added it to the water. At the moment, the caustic soda is sitting in a layer on the bottom of the bowl. The fumes have not started to form yet.
Stir the mixture gently, being careful not to splash any of this liquid. The vapours are now forming and are sucked out by my exhaust fan. It is a similar consistency to stirring sugar into water as the caustic soda is granulated. During this process, a chemical reaction is occurring between the caustic soda and the water. This creates a large amount of heat.
I have now moved the bowl with the caustic soda mix to my paper covered bench. Now that the caustic soda has dissolved into the water, the fumes have all gone and it is safe to leave on the bench. It is still dangerous though and can cause chemical burns so should be handled with care. I have my candy thermometre in it to check the temperature. It is currently about 70 degrees celcius and needs to cool down to 50 degrees.
It is now time to heat the oils to melt the solidified fat and copha. I cut mine into cubes so they melt quicker. I heat mine over a low heat until almost melted and then turned the heat off. The residual heat in the melted oils finishes the job off for me and, usually, results in the oil being the required 50 degrees celcius.
It is now time to prepare my mould. If this is your first time making soap, I would advise that you prepare your mould first. I have learnt now that I have more than enough time to prepare my mould while I am waiting for the caustic soda solution to cool down. I am using a rectangular plastic container that I picked up in the $2 Shop. The plastic is flexible and will bend a little.
The first step to preparing a mould is to spray it with kitchen spray or cooking oil. I gave it a liberal coat so that the soap will come out easily.
I have lined this mould with greased proof paper. You need a lining that can stand up to heat. I have tried this mould before and didn't line it. I had a lot of trouble getting the soap out so I have lined it this time to make it easier on myself. I have taped the paper to the side of the container too as it will be easier to pour the soap into the mould.
The oil mix and caustic soda mix are both at the correct temperature now. I have added them together. You need to added the caustic soda mix to the oils for safety. Notice how the caustic soda mix has sunk to the bottom and has changed colour. This mix is still caustic and can burn so make sure you are still wearing your gloves.
This photo was taken as I started the stick blender. It takes between 5 to 10mins for the soap to become stable and reach the stage known as trace.
This photo shows the signs of trace. You know you have reached the trace stage when you can stir the mixture and ripples remain on the surface. The mixture is very runny originally. As you mix it, it thickens up in a similar way to making a white sauce or gravy on the stove. Once it is thick enough, the ripples form and don't break down when you stop stirring. The soap is now stable and can be put into a mould to set. If you choose to use colours or scents, now is the time to add them.
In this photo, I have added some orange soap colour and also a mango scented oil. I am mixing it with a spoon at this stage as I find it provides a more even consistency. It smells lovely at this stage.
The soap is now ready to be poured into the mould. You can clearly see the trace in this soap. It is holding the patterns I have made in the top of the soap and has even withstood several bangs on the bench to smooth it out!
This is the last photo for now. I have transferred the soap to my dining table to cool down where it is not in the way. I have covered it with 2 towels so the the whole container is enclosed and it can cool down slowly. It takes about 24 hours until it is cool enough to set and can be unmoulded. I will cover the un-moulding and cutting of the soap in my next post.
I hope this has helped to make the process of cold process soap making so much more achievable and less daunting for you. Have fun with it. I must warn you though, once you start, soap making is quiet addictive. Most of my family and friends will be getting home made soap as a part of their presents this year!!