To start with, it's a good idea, to know a bit about the soapmaking process. All soap (and by that I mean true soap, NOT detergent) is made by combining oils and fats with a strong base solution. This splits the oil or fat up into it's component parts, fatty acids and glycerine, and then further reacts with the fatty acids and turns them into soap.
Soap which is mass produced mechanically in a factory has the glycerine removed (the most common reason being that it clogs up the plodder - the machine which pounds it into bars), but handmade soap has all that lovely glycerine left in, which makes it nice and silky and is said to be good for the skin.
There are lots of oils/fats that can be used to make soap, and each one has it's own special properties. Coconut oil, for example, produces lots of small but profuse bubbles, whereas castor oil produces big bubbles, but not a lot of them. Palm oil will produce a rock hard bar of soap, whereas olive oil will produce a softer soap which dissolves quickly and can produce a slimey deposit if left sitting in water. For this reason, it's not always a good idea to use one single oil in a recipe, and through experience (and some trial and error) you will learn what is a good combination. I like to use about 50% palm oil, 25% olive oil, 20% coconut oil and 5% castor oil. You don't have to use these 4 oils if you don't want to. Some people like to use rapeseed oil, sunflower oil, even lard or beef dripping. The choice is yours.
The other vital ingredient, without which you cannot make soap, is sodium hydroxide (NaOH), also known as caustic soda or lye. Potassium hydroxide (KOH) is also used in soapmaking, but generally for liquid soaps, which is beyond the scope of this article. Sodium hydroxide can be bought in most hardware stores as drain cleaner. Make sure you check the ingredients, it should contain 99% sodium hydroxide.
Now the fun part starts! This is where you calculate the amount of caustic soda (lye) and water required to turn your oils into soap!
One more thing before you begin. It is important to make an allowance in your calculations for the "superfat". The superfat is a small amount of oil which will not be saponified (turned into soap). This is intended as a safety margin because fats and oils are not all the same, different batches from different crops will have variances in their fatty acid makeup. There may also be differences in the purity of the caustic soda purchased, varying from batch to batch. And if all the oil is turned into soap there is a high likelihood that there will be some caustic soda left in the soap rendering your batch harsh, unusable, and probably downright dangerous! Caustic soda is highly corrosive and will burn your skin, eyes, or anything else it touches. Consider yourself warned!
Ok, so, safety warning over. Because you'll be working with a dangerous chemical, it is important to wear suitable protection. I like to were a plastic apron, plastic gloves, and safety goggles.
So, assuming you're going to use my recipe above, and you want to make a kilo of soap, you will need:
500g Palm oil
250g Olive oil (pomace oil is best - but I don't recommend extra virgin)
200g Coconut oil
50g Castor oil
140g sodium hydroxide
350g water
Each oil has it's own SAP value (which is how much caustic soda is required to fully saponify 1g of oil), and to come up with 140g I took the SAP value for each oil and multiplied it by the number of grammes of oil used, then added all those values together. I then deducted 5% to allow for a small superfat. For the water amount, I like to use 35% of the weight of the total oils used. More than that and I tend to find my soaps shrink too much as they're drying out, less than that and it can seize during the soapmaking process making it impossible to pour into your mold.
If you would prefer a video guide on soapmaking, I highly recommend Soap Making Fun.
Click here to get it.
Now comes the really fun part.
- Measure out all of your ingredients. Use scales which go up in small increments. 5g increments will do. The water must be weighed as well. Note the recipe is in g, not ml!
- Find yourself a suitable mould. And old tupperware box or clean ice cream tub works well.
- Put your solid oils in a stainless steel pan (NOT aluminium - the caustic soda will ruin it!) and put it over a low heat to melt.
- Open your kitchen window and put your COLD water in a stainless steel, pyrex, or heat resistant plastic jug and SLOWLY stir in the caustic soda. Take care during this part. The water will get very hot and the steam which comes off is very caustic. Do not breathe it in or get into your eyes. Once the granules are all dissolved, set it to one side to cool for a bit.
- Once all your solid oils are melted, remove from the heat and stir in your liquid oils. Now, the temperature that you mix your caustic soda solution and oils together is not absolutely critical (though some die-hard soapers says it is). Just put your hand on the side of the pan and jug and if they are both roughly the same temperature and not too hot to leave your hand there, they're ready to be mixed. Start stirring with your spoon (stainless steel, of course) and slowly pour in your solution. Now, keep stirring. And stirring. And stirring. Eventually, the oils will begin to change and thicken. You will know when it is ready when it has the consistency of custard/pudding. This is called "reaching trace". You will know if it has truly reached trace because you should be able to pour some off your spoon and it should leave a trace on the surface. If it takes a very long time and your mixture is cooling down, you may mistakenly think it has reached this stage when in fact it is just the solid oils going hard again. If this happens, put the mixture over a low heat again and keep stirring.
- Alternatively, you could skip all this stirring and heating business and just whizz the whole thing up with a stick blender. You'll be amazed at how quickly this speeds the whole process up. A batch this size will take about 5 minutes at the most.
- Once your mixture looks like custard, carefully pour it into your mold. Leave to cool or preferrably overnight. Once it is cold, put it in the freezer for a few hours. This will make it much easier to get out of the mold. Once it's defrosted you can cut it into bars using a sharp knife. It is, however, still caustic at this stage, so now you need to place your bars on a shelf or tray and place it somewhere dark and dry for a month. Yes, a month! This is to allow your bars of soap to dry out and cure, resulting in a gentle, long-lasting bar.
And that's all their is to it. Of course, once you've made your first plain batch you'll want to experiment with colours, fragrances, packaging, etc, but I'm afraid that will have to wait for another day.
Before you go ahead and make your first batch, I have some recommended reading for you.
Check out Sandy Simmons' "The Super Soapmaking Book".
I hope I've given you an insight into how to make your own soap and you give it a go yourself.
Happy soaping!
