The important thing to remember with making soap from scratch is that raw soap is caustic and can burn if you get it on your skin. Particular care also needs to be taken with the caustic (lye/NaOH) and water mixture, you need to ensure that no one drinks it or splashes it on themselves. If you do splash it on yourself you need to immediately rinse the area with cold water until the burning stops. If the burn is significant or the caustic and water mixture or raw soap is splashed in the eye or consumed internally please seek IMMEDIATE medical attention.
After 72 hours or so after being made and moulded, the chemical reaction (called saponification) should have mostly taken place and the soap should no longer be caustic and you can touch it with bare hands without any worries. Prior to this you should touch the soap only when wearing gloves else you may find it harsh on your hands.
I know all of the above sounds quite alarming (!!) but a healthy appreciation of the nature of soapmaking is necessary to ensure that accidents don't happen. It really isn't difficult to actually make soap at all and the end result is well worth it. Just ensure that you take proper precautions and keep kids, animals and husbands or wives out of the way.
A good recipe for handmade soap from scratch is:
450 grams olive oil
250 grams coconut oil
250 mls chilled water (spring or de-ionised)
90 grams caustic soda (sodium hydroxide/NaOH)
20 mls of essential or skin safe fragrant oils
1/4 cup ground herbs or ground oatmeal
1 tablespoon of cosmetic clay
Another Soap Recipe
250 grams macadamia nut oil
Macadamia nut oil is a lovely oil to use in soaps. Macadamia nut oil is very close (molecularly) to our own skin sebum so it is nourishing to have in soap.
The coconut and castor oils make for great big bubbles. The coconut and palm provide initial hardness, with the olive adding to that later as well.
600 grams olive oil
This recipe can be soft at first and needs a good six to eight weeks to age. As with all soaps high in olive oil once they are thoroughly cured and aged they make for a very hard and long lasting bar.
The ingredients in this recipe are very nourishing and this soap would suit those with sensitive skins.
These recipes make about 8 full sized bars of soap.
Cover benchtops with newspaper and also put a layer on newspaper down on the floor in case of any splashes. If you get any splashes on benches etc wash area and then apply vinegar to neutralise. Wear safety goggles, rubber gloves, long sleeves/trousers and footwear. Use accurate scales to measure your ingredients.
Measure your chilled water and pour into a tall sided pliable plastic jug or bucket. While wearing safety gear measure your caustic soda and then pour the caustic soda INTO your chilled water, stir well with a plastic or stainless steel long handled spoon until the sodium hydroxide dissolves. Set aside in a safe place and allow to cool to at least 40°C (use a stainless steel thermometer). This is best done in a well ventilated room. You will get some initial fumes - try not to breathe them in. I mix this caustic and water mixture in the kitchen sink to contain any spills.
Measure your oils and, in a large stainless steel saucepan or small stainless steel stock pot, heat them gently. Once the solid fats and oils are melted allow the temperature to drop to 40 or 45° C.
Slowly pour the caustic and water solution into the melted oils. Be careful not to splash while combining the mixtures. Stir with a long handled plastic or stainless steel spoon until the mixture traces. If tracing takes more than 15 minutes, which it often does, stir for the first 15 minutes, then stir for 5 minutes at 15 minute intervals. Tracing looks like a thickened homemade custard. To test if your mixture has reached trace, dribble a line of soap across the top of the mixture. If the line remains visible on top then the soap has traced. If it sinks into the mixture quickly then you need to continue stirring. If you have a handheld stick blender you can use that to reach trace, give it short steady bursts and stir in between.
Once tracing occurs you can add the 20 mls of essential or skin safe fragrant oils. Stir in well. You can also add ground herbs or oatmeal for texture (I usually add about 1/4 of a cup but it's a personal thing and you may find you like less or more). The more finely ground the herbs or oatmeal the better, coarse herbs/oatmeal can be unpleasantly scratchy rather than exfoliating. Cosmetic clays can also be added. Mix them with a little bit of water first before adding at trace (so they incorporate easily). You can mix thoroughly for a solid colour or just gently stir through once or twice for a swirled effect.
Pour the soap into your mould. A good mould for this recipe is a 1 litre washed milk carton or a 1 litre takeaway container lined with a freezer bag. Put a piece of clingwrap over the top of the filled mould and put it aside (somewhere out of the way) and loosely wrap around a couple of towels to insulate the soap. After a day or two the soap can be turned out of the mould (or with the milk carton the mould is torn off). If the soap is very soft still (dents easily), allow it to cure for a few more days to further firm before cutting (it cuts best when the texture/firmness is like cheddar cheese).
Cut soap into bars and set the bars out on a cake rack to cure and dry. This will allow the bar to further firm and finish saponification. Let them sit for 4 weeks to fully harden and to allow as much water to evaporate out as possible. I use a paint scraper to cut my bars as it is thinner than a knife and sometimes knives can be too thick and cause the soap to chip and crack whilst you cut it. The more time that soap is allowed to sit the harder it becomes and the longer it will last when being used.
Continue to wear rubber gloves when washing up all the utensils.
Making up a recipe yourself, using one from the net or a friend or changing one you've been given? ALWAYS re-run your recipe through a soap calculator to make sure that the amount of caustic soda (NaOH) is correct. Typos *do* happen! Much better to spend a few minutes double checking than to ruin a batch or worse.
Accuracy in weighing is IMPORTANT. Inaccurate measuring can make for a very harsh or very soft soap.
Only use pliable plastic jugs, plastic or stainless spoons and stainless steel saucepans. The caustic nature of raw soap does not react well with glass, brittle plastic or metals other than stainless steel.
Store soap which is not in use in a cool dry area. In a paper bag in the linen closest is always a good spot.
Don't let handmade soap sit in water between uses or sit directly under running water for any long duration as it soaks the water up and gets mushy (the technical term!).
Want to add colour to your soap? This is easy with ultramarines or oxides. A medium strength solid colour is approximately 1 teaspoon per kilo of oils. You can add this colour to your caustic water or at trace. It helps to blend the ultramarines and oxides with a little water first if adding at trace, to help them incorporate in better. Give a good stir with the stick blender to get a nice even solid colour. If you are wanting to swirl these colours through you may only need 1/2 teaspoon of colour. If swirling remember to add your scent first before you colour. Pour off into a jug a small amount of soap, mix the colour in thoroughly, pour the coloured soap back into the pot, stir the mixture gently (once) and then pour off into the mould.
If buying caustic soda from the supermarket don't get Drano, it contains additives. You need to get a brand which says 98-99% pure, commonly Digger's Brand.