Sunday, October 5, 2008

Gel phase and Unmoulding of CP Soap

A good way to understand if your soap is coming out properly, is to have a quick peek after 2 to 4 hours after pouring. By this time, properly mixed and insulated soap will have reached gel phase, and will look translucent and *much* darker then when you poured it. This is perfectly normal, and really, I think this is the only way to be sure that what you've done is going to be soap.... soon! :-)

Since there's no precise steps to follow at this stage, I will simply give you a list of notes and comments:

*Try and keep the soap in gel state as long as possible (that is, do not move the moulds or remove the insulation layer).

*After 12 to 24 hours, the soap should be ready to unmould.

*Properly made and insulated soap is opaque and solid, and should not be covered by any "soap dust".

*Soap dust is a white powder that may appear on the surface(s) of the soap exposed to air. Chemically speaking, this may or may not be sodium carbonate, a mild alkaline salt that forms when the still caustic soap mixture reacts with the air surrounding the soap, and is totally innocuous. Another theory is that this white powder is simply "dry soap". Discussions abound on this subject, and my personal conclusion is that it's not worth worrying (too much) about it.... :-)

*Unmould the soap and leave to cure at room temperature.

*Arrange the soap on your chosen "cooling racks" (for instance, clean carboard trays, such as those used by greengrocers for exotic fruit) so that air can circulate around each soap.
If you live in a very humid climate, it might be safer to cure the soap in air tight plastic containers. Experiences and opinions on this subject are not unanimous - my personal experience is that a humid room is a lot more "dangerous" than an air tight plastic box, and I know of soapers (in tropical Australia) who simply avoid making soap during the monsoon season.

*Curing is basically needed to get rid of the excess water, as well as an extra precaution to make sure no free alkalis are present.

*Well cured soap has a richer lather and lasts much longer than fresh soap.

*If you have precise pH strips, you can test the alkalinity of your soap. At the end of the saponification process, natural soap will read between 9.0 and 10.5.

*On the pH of soap, I recommend Ann Perius-Parker's article, available from Kathy Miller's fantastic soap info site.

*In my experience, the pH of properly prepared, mixed and insulated soap does not change over time.

*There are more empirical ways for testing the alkalinity of soap. The most popular is called "tongue test", and I personally like the way "Hersh" (James Hershberger) describes how to do a tongue test without burning one's tongue off.

*A simpler and less painful method, is to wash your hands with the soap. If it burns, or if it leaves you with a "boiled skin" feeling (similar to what happens after soaking in a hot bath for a long time), or if the lather feels slimy and rinses off with difficulty, then the soap is still caustic.
This might change over time. So before deciding your soap is too caustic, leave it to cure for another few days.

*If the burning/slimy/boiled skin sensations are still present after one week from unmoulding, then there is too much free caustic soda in the soap. Double check your recipe and notes: did you leave one of the base oils out? Did you check the accuracy of your scales? Did you double check the initial calculations using a reliable SAP calculator?

*In my experience, soap that still feels caustic after two weeks from unmoulding is most likely a "lye heavy" batch.

*The fact your soap is lye heavy doesn't mean you must throw it in the bin. On the contrary! Soap can always be rescued - for instance, you can rebatch the soap adding some extra oils, or you can make some laundry gel.

I hope you've found this information useful. If you would like to discuss further, you might like to consider joining a qualified soap making list, such as Soap Naturally.



Source: http://www.aquasapone.com.au/soapmaking/coldprocess_soap3.html

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