Making cold pressed soap - focusing on the process

20 May 2009
I made a batch of soap last weekend. For me, soap making is one of those defining tasks of a simple life. Like bread making, it is a powerful reminder that the products needed in the home can be made better, and often more economically, than those bought at the supermarket. Those two tasks, more than any others, also connect me to my past. Making soap and bread would have been a normal part of our ancestors' lives. Now let me qualify what I just wrote. You can buy soap cheaper than you can make it, but that soap will contain almost no glycerin - the moisturising and nourishing part of soap, and it will contain a lot of chemicals to make it smell good, and to make it lather. When you make your own soap you need only three ingredients - fat, caustic soda/lye and water. So homemade soap is not cheaper than commercially produced soap like Palmolive, but it is cheaper than the "natural" soaps you buy in the organic shops. All soap, no matter what the label says, even the "natural" ones, have been made with caustic soda/lye. The process of soap making neutralises it and after having the soap sit on your shelf for a few weeks, you will have the finest soap money can buy. Caustic soda/lye is Sodium Hydroxide (NaOH).

I have written about this in the past and there seems to be a reluctance by some to take up soap making, mainly because of the safety issues. And you are well advised to be cautious of this process - you need to work with caustic soda / lye and that will burn your skin, your benches or floor if it falls from your container. It is wise to be cautious, particularly if you have children or pets around. So I thought that it might be helpful if I focused on the process rather than the recipe. Seeing it being done in steps, might help some of you work out a way you can make soap that you feel safe and confident with.

My soap is made with olive oil, rice bran oil, copha (solid coconut oil), water and caustic soda/lye. Here is my soap making tutorial. There is a soap calculator here. Basically, you find what you have in the cupboard, or buy your preferred oils, enter them in the calculator and it will estimate the amount of water and caustic soda/lye to add. Soap making safety, read this.

So now let's focus on some of the issues you might encounter when making soap.

Before you start, make sure there are no children or pets around. Put on your safety gear. Work in a well ventilated space. When you add water to the caustic soda/lye, it will emit fumes. Traditionally, soap making ingredients are measured as solids, not liquids. Get yourself a good scale and weigh your ingredients according to the recipe. Remember that as soon as moisture is added to the caustic soda/lye, and that might just be a bit of moisture on your hand, it will start to burn.

I use a Pyrex jug to mix my caustic soda/lye and water. As soon as you add water, it will start to heat up. You do not have to add heat, it heats up itself. I place my pyrex jug on a board so it doesn't damage the bench top. I use rain water from my tank. If you only have tap water, measure out a bit more that you need and let it sit in a bowl for 24 hours. That will allow the chlorine to evaporate off.

As soon as you add water, the reaction will start. You can see small bubbles in the water here as soon as the caustic soda/lye was added.

And less than a minute later, the solution has reached 90 C (180F).

This photo shows the combined oils before the caustic soda/lye was added. The mixture is clear. Basically, soap is made by mixing the caustic soda/lye with water and letting it cool down. While this is happening, you heat up the oils on the stove. The aim is to get both solutions at the same temperature. When that happens, you mix them together, then start mixing. It's really a simple process, made more difficult by the danger of burning.

When the caustic soda/lye is added, the mixture is opaque.

My bowl was very full, so I placed some tea towels around the mixer to prevent splash damage on the bench.

After mixing for about six or seven minutes, I reached trace. Trace is the stage of the process when ripples made on the surface of the mix, stay there. You can clearly see this in the photo above. When you reach trace, you stop mixing. If you want to add an essential oil, you add it when you reach trace. I then poured it into the moulds, covered them with a few towels and left them over night. You don't want it to cool too fast.

The next day the mix was solid, so I took it out and cut it.

I like to cut my soap into long bars instead of square or thin bars. I like a solid piece of soap that will last a while. You can cut the soap any way you like or you can use various moulds to shape the soap. Leave the soap on a rack to cure for a few weeks. This also hardens the soap so that it will last much longer.

So I have made 20 good bars of soap at a cost of about A$17.40 or 87 cent a bar.

When the soap is cured, wrap it in greaseproof paper and store in the cupboard until it's used.

For those of you who kill your own animals or poultry for food, Carla Emery has some fine recipes for soap making using tallow - page 615 (updated edition 9). Her soap making section contains a lot of good information, including info on water and fats and how to make your own lye. It starts on page 610.

If you are new to soap making and are still apprehensive about it, I encourage you to go to your library and get Carla's book. The ability to make your own soap is a fine skill to have. When you get over the first soap making session you'll realise it's quite a simple process that, when combined with prudent safety precautions, produces soap that is much better than what you buy at the supermarket.