In the soap-making world, knowing how to formulate a successful soap recipe is what sets you apart from the beginners. The key to formulating your own soap recipe is to know your oils and what properties they will bring to your handmade soap. Once you know the different characteristics of each oil, you can begin experimenting with your tried-and-true, basic recipe for something more elaborate.
A good place to start your research is online. If you go to soapcalc.com, you will find a lot of useful information. At the top of the page, you will see different tabs. If you click on the tab for SoapCalc9 WP, it will take you to a soap calculator. Along the left hand side, you will see a chart for hardness, cleansing, condition, bubbly lather, creamy lather, iodine and INS. To find out what these properties will mean for your finished soap, click on the “soap qualities” tab at the top. Scroll down a little bit and you will see a description of what each property is and a number range you might want to aim for with your soap recipe.
Now that you have some numbers to shoot for, you can go back to the calculator page. In the middle of the page you will see a list of oils listed alphabetically. By clicking on each oil, you will see the numbers on the property chart change. This enables you to see what each individual oil will add to your soap. If you need harder bar, add more oils or butters that have a high hardness number. If you enjoy a rich lather, more oil such as castor oil will give you what you are looking for.
By double clicking on each oil, it will transfer that oil into the recipe box on the right hand side. Here is where you get to play a little. Right above the list of oils, you will see a place to enter your total weight. This is the total weight of the batch you plan on making. I recommend starting off with a one or two pound plain, unscented batch so you can see how well your soap will turn out without any other factors influencing the outcome. It will also allow you to experiment without wasting a lot of supplies if it doesn’t turn out how you expected.
Decide how much of each oil you would like to add to your recipe. As you add more oils and hit “compute recipe” at the bottom, the numbers on the chart will change under the “combined” column. This is telling you how well your oils will perform when combined together. These numbers correspond with the numbers range you found on the “soap qualities” page. If you don’t find the combination you’re looking for the first time, increase and decrease the oils until you find the numbers you want.
You may notice that the higher the conditioning number is, the lower the hardness is. This is not to say that you may have a ball of soapy mush when your soap is cured. It just means it may need to cure longer than usual before all the water evaporates from your bars of soap.
Towards the bottom of the page, it will tell you how much lye and water you need to saponify the oils you have chosen. As always, for safety reasons, run each new recipe and each change you make to a recipe through a soap calculator to make sure you have the right amount of lye and water. Each oil has a different level at which it will saponify.
Once you have developed a recipe and have found you are happy with the finished product, then you can consider adding the extras, such as fragrance or color. When you are able to formulate your own recipe, it will give you a sense of accomplishment in your soap making endeavors.