When I embarked on my very first batch of cold process soap, two of these questions came to mind as I melted the oils, added lye water, mixed and poured the batch into the prepared mold.
Still, I wondered what constituted a fully cured bar and how I could know. I mean, six – eight weeks? Did that mean that any point between six and eight weeks the soap was ready, or was I looking for specific signs that the soap was cured? Surprisingly, I found no one who could clue me in.
It took several years, but I am happy to say that I now know the answers to each of the original questions.
Is it soap yet? Although trace is the hallmark sign of saponification, the mixture actually
becomes soap once the oils and lye water come together and emulsify, which occurs before trace. Soapmakers who want as much time as possible to create designs quit mixing at this point. Whether you choose to wait until trace or stop at emulsification is entirely up to you, but if more time to design is important, begin as soon as the oils and lye water combine and do not separate.
When may I try the soap? Soapmakers are always eager to try their creations and may do so as soon as no lye is present in the soap, but it is likely more harsh than a fully cured bar and some report skin irritation at this point, so take care. Please be clear that this bar is for testing purposes and personal use only. Do not give baby bars away or sell them at this point. The soap is not cured.
How do I know when soap is cured? It was several years before I found an answer to my query, but I learned that soap is cured when it stops losing weight.
Here is the procedure for curing and judging a cured soap: Make a batch sheet form or at least an index card. Record the date the soap was created and the date it was ready to cut. On cutting day, choose one bar and mark it somehow to weigh the same bar each time. Weigh the bar carefully and record the date and weight. Repeat this procedure each week until the bar weighs the same two weeks in a row. The soap is now sufficiently cured and ready to wrap.
Now, if you feel strongly that a longer cure is a better cure, by all means, cure longer. Soap does indeed continue to dry out and become milder as it is affected by the acidity in the environment.
Now you have it. Go forth and make soap!
Until next time, may your days be filled with bubbles and wax.
Beth Byrne for Making Soap, Cosmetics & Candles
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