Making Soap - Tips and FAQ

Basic Recipe
Pictorial Recipe
Tips and FAQ
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Notes on Lye:
Lye will react with some metals, including aluminum, zinc, and tin.  Do not use containers made of these materials.
Contact with lye can cause injury, as can ingestion or exposure to fumes.  Exercise care when handling lye!

"Green" Soap:
Soap that has hardened (2-3 days or so) but not yet cured is still very caustic.  Exercise the same care when handling it as you would with pure lye.

Mixing Temperature:
It is very important that the lye and fat are the same temperature when mixing begins.  If no thermometer is avaliable, this may require some trial and error.


Q:       How can I tell when the soap is ready to pour into the molds?
A:       The mixture is ready when it "traces".  Allow some soap to drip back onto the heating soap.  When  is ready it should leave a small mound.  Alternately, draw a line in the liquid soap with the stirring utensil- It will leave a trace for a few seconds when ready.

Q:        Why is my soap seperating as it cures?
A:        Soap will re-seperate into lye and fat if cooled too rapidly.  You can re-melt the soap and pour it back into the molds, taking care to keep it warmer as it hardens.

Q:       Why is there a white powder forming on my curing soap?
A:        The white powder which can form on the surface of soap as it cures is soda ash, formed as lye reacts with carbon dioxide.  You can try to prevent it from forming by covering the soap with plastic or waxed paper while it cures, if avaliable.  If not, the soda ash can simply be cut or washed off after the soap has cured completely.

Q:         Why are there bubbles of clear liquid in my soap?
A:          If you cut the soap before curing and see bubbles of clear liquid, it is pure lye.  Be careful!  Reduce the amount of lye or increase the amount of fat you use in subsequent batches.

Q:        Why does my soap smell like a rotting animal carcass? 
A:         If too much fat is used, some of it will not combine with the lye, and will go rancid.  Adjust proportions accordingly.

Q:        Why is my soap slimy?
A:         "Slimy" soap can result from incorrect portions of ingredients.  Take care to make accurate measurements.

Q:        How can I cut the soap?
A:         If you are making a large quantity of soap or do not have any molds, you may wish to mold one large slab of soap and then cut it into smaller bars.  This is easily done with a piece of wire, as a knife will chip the cured soap.  Alternately, you can cut the soap with a hot knife when you remove it from the molds, before curing.

Q:        Can I make soap that doesn't smell like nothing?
A:        You can add just about any aromatic oil or other fragrance you can think of to a basic soap recipe to make scented soap, as well as milk, honey, herbs, or countless other additives that serve a cosmetic or medicinal purpose.  See the links page for ideas and recipes