Before you get started, there are some specialized soapmaking terms you need to understand. Most of these terms will apply to the other techniques in this book. You'll find that soapmakers often use these terms, but there is some variation from location to location and process to process.
A trace state is described from “light” to “heavy.” A soap is said to have reached “full” trace when it is at the state desired to do what you need it to do next. When a soap mixture “traces,” it has reached a certain level of saponification and you will add color, scent, and other materials at varying levels of trace. As you gain experience, you'll be able to recognize the signs of trace with no problem at all.
Oils and lye just combined. Note transparency.
When the oils and lye solution are first mixed, the solution will be transparent, and as you stir, it will become less so. Opacity and a slight graininess lets you know that your soap is tracing. There is also a subtle “soap smell” that comes at the same time. It isn't possible to describe it, but you'll come to recognize and be reassured by it.
What exactly is cold-process soapmaking?
The cold-process soapmaking technique is relatively simple and gets easier with practice. A blend of oils is mixed with a simple solution of lye and water, stirred until thickened, and poured into a mold. It's as simple as that.
If you've made gravy or pancake batter, you've experienced the changing texture that many soapers compare to trace. A light trace may be like a thin pancake batter, a medium trace like a medium-thick gravy. If your soap gets gloppy, you've got a heavily traced batch, and you need to get it into its mold as soon as possible.
Showing a medium trace.
Trace issues will cease to be issues at all as you make more and more soap. You must stir your soap to trace before pouring. If your soap hasn't traced, it will likely separate and remain unsaponified in layers of oils and lye solution. There are some recipes that have special trace needs, and they are indicated in the recipe instructions.
The saponification process continues until all the alkali and acid (the lye and the oils) have reacted. In cold-process soapmaking, this can take a few weeks or more. As the soap ages, the reaction slows down considerably, and eventually no unreacted alkali remains. “Young” soap will still have some alkalinity, and this level decreases as the soap ages.
Alkalinity, and acidity as well, is measured on the pH scale. This scale is divided into a range of pH measures from 0 to 14. Substances with low pH factors, such as lye, are “alkalis” or “bases,” while those with high pH factors, like vinegar, are “acids.” Neutrals are found in the middle, around pH 7. Your soap should have a pH between 6 and 10.
A soap is said to be “fully saponified” when there is exactly enough oil and lye to fully react. Since you usually want a little extra oil in your soap, for gentleness and moisturizing benefit, most soaps are formulated with slightly more oil than will completely saponify.
This is called “lye discount” or “superfatting.” You may create a gentler soap by calculating a lye discount into your recipe. A lye discount is a reduction from the total amount of lye needed to saponify the oils to a lesser amount. Another way to create a gentler soap is to superfat, by adding extra oils at the end of the stir, before you pour. Overly lye-discounted or super-fatted soap is softer and prone to rapid spoilage. Lye-heavy soap is a worse problem, as it makes harsh, caustic, and unusable soap.
The lye soap recipes in this book are created with a 5- to 7-percent lye discount, and most of them contain one or more superfatting agents. If you want to add more superfatting agents, keep it to 1 tablespoon per pound of oils, or you'll get soap that is soft and spoils more quickly. You may prefer to add the superfatting agent at the beginning and calculate it into the oils when you make your own formulae.
It is a good idea to clean up as you go. With lye soaps, use kitchen sink to corral the lye-touched objects as you finish with them. Rinse the lye pouring pitcher with water and a splash of vinegar, then fill it partway with water and more vinegar so you can place the other things in a neutralizing bath.