Formulating Soap Recipes - Copyright of Lisa Wood-Bradley
You can make formulating soap recipes easy or complicated depending on what you are trying to achieve with your end soap. We'll look at both ways here.
If you just want to make a straight forward basic soap that cleans well, feels good, lasts a good length of time and has easy to find ingredients .... what do you look for?
A long lasting bar of soap will need to have good percentage of hard oils (solid at room temperature in most seasons. Some hard oils may liquify or soften in hot weather, such as coconut oil.) Except for olive oil which does result in a hard bar of soap when aged for a suitable length of time, all other soft oils (which are liquid at room temperature all year round, ie sunflower) will make for a softer bar of soap. Softer soaps do not last as long with use as harder bars do.
All oils, fats and butters when saponified properly and turned into soap clean well. Some clean better than others but this is mostly a consideration when making laundry soap, for example. For cleaning the average human being any oil will do!
Because handmade soap is naturally high in glycerine (a by-product of the saponification process) it tends to feel kinder on your skin than commercial soaps do (because the glycerine is removed during commercial soapmaking process for use in other products). And when a soap is superfatted (where less than 100% of the alkaline (ie caustic soda) needed to make oil into soap is used and therefore free fatty acids remain) it is even kinder to the skin, leaving it feeling cleansed and moisturised.
Easy to find ingredients? Check out the supermarket! In the refrigerator section you will see all sorts of goodies that can be used to make soap. Copha is coconut oil and makes for great lather, a hard bar, as well as being a good cleanser. Frymasta (the yellow wrapper) is actually palm oil. Supafry (the red wrapper) is tallow. Both of these help make a long lasting bar of soap. Lard is another good fat for aiding soap longevity, it also has lovely fluffy lather and is conditioning.
In the oil section you have all sorts of goodies, such as sunflower, canola, macadamia, grapeseed, olive oil, safflower and so on. All of these are great in soap and conditioning to the skin. Just remember if getting a blended oil to make sure you know what oils and in what percentages are contained in the blend, so you can accurately enter the figures into the soap calculator.
Of course in the cleaning aisle is the caustic soda! (NaOH). Get the brand (usually Digger's) which is 98-99% pure.
Also your liquid ... there is milk, de-ionised water and spring water that you can use.
Okay, the supermarket has all the ingredients you need ... now what?
You decide on what percentages to use of hard and soft oils. You want your soap to last a decent length of time so aim for between 40% to 60% hard oils. Soft oils can be more conditioning than some hard oils (for example olive oil is more conditioning than palm oil). So aim for a good proportion of soft oils in your recipe, at least 40%.
Once you have decided on what oils and/or fats you want to use in your recipe you need to calculate the recipe using a Soap Calculator. This will tell you how much water and caustic to use to make your soap. I usually aim for 5% to 7% superfatting range and 30% water in my basic soaps.
And that's it ... done!
Okay ... maybe "complicated" isn't the right word ... I wouldn't say that below is a complicated way of formulating a soap recipe as such. It just takes into consideration some of the other properties of the oils. All other bits remain the same.
There are a couple of considerations I take into account when I am making soap recipes. What does the oil do? For example is it healing/soothing like emu oil? Is it rich in vitamins like avocado oil (unbleached)? What other essential fatty acids does it have? What am I trying to achieve with the recipe?
In the Carrier Oil page you will find that the properties of the oils has been listed there. I pour over this information when formulating new recipes for specific soaps, such as shampoo bars, skin soothing, shaving or facial soaps. It's a good starting point in deciding what oils to use in your recipes.
I will also look at the fatty acid break down of the oils too, the lauric, linoleic, oleic, palmitic, ricinoleic, stearic and iodine values), to determine how conditioning a soap it will be, or how hard or how big the lather is. (I love fluffy lather!).
lauric acid for cleansing, big lather, hard bar
linoleic and oleic acids for skin conditioning
palmetic and stearic acids for consistent lather and a hard bar
ricinoleic acid for skin conditioning with consistent big lather
iodine the lower the value the harder the bar
When making specific soaps, as opposed to regular bath soaps, I tend not to be so concerned about whether or not the soap has a good portion of hard oils for longevity. I can always add stearic acid to the recipe if it is particularly soft (ie has a lot of hemp or avocado oil for example). Or I can just take it into consideration that it will be a softer bar and make sure that I don't leave it sitting in water for too long and use a bath scrubby rather than washing with the soap directly (as this aids longevity).
I also consider what other additives I may want in my soaps. For example do I want to infuse any herbs in the oils? For a skin soothing bar I'd look to infusing calendula, chamomile or lavender in one of the oils. Do I want to include clays? For shaving soaps kaolin or white clay is a great additive as it makes for an easier glide of the razor. Pink and green clays are great for facial soaps. Do I want to add any exfoliants? Is this a soap for "hard wearing" body areas such as elbows and feet? Exfoliants would be good in these soaps.
I often superfat higher with specialty soaps as well, particularly those with butters or emu oil in them. Around 8% to 10%. I want to get all the extra benefit of the free fatty acids!
Once I have worked out what I want the soap to achieve, and work out what oils and additives I need to get this result, I just plug in the oil amounts into the Soap Calculator as with the basic recipe and away I go!