Care & Feeding of your Milky Way Molds
Because opaque cold-process soap undergoes a chemical reaction in the molds, there are a few extra considerations to keep in mind. (Note: these considerations don't apply to Melt & Pour or transparent soap since it's neutral when poured. Transparents also lack "Stickiness" so there shouldnt be any problem unmolding them).
1. Soap needs a certain amount of heat to saponify properly. Heat is easily lost in the individual 3-ounce or 4-ounce molds. Heat your soap to 115F-125F when using these molds.
2. When filling many cavities, realistically consider just how much working time you have before your soap begins to thicken beyond the "easy-pour" stage. If your soap does thicken before all the cavities are filled, spoon the soap in and tap the molds lightly on the counter top. The clear plastic will allow you to see if any air bubbles remain on the mold's detail surface.
3. Superfatted soap and/or soap high in soft oils such as canola, avocado, safflower, etc. are a bit sticky, and therefore may unmold with more difficulty than firmer soaps high in palm oil or tallow. These softer soaps will unmold easily if placed in the freezer for 1/2 hour.
4. More on unmolding soap. If the soap is allowed to remain in the molds for 12-24 hours after cooling down, it releases much more easily than unmolding it immediately upon cooling. (During this extra time it's both shrinking and crystallizing.) One final option: If you'd like to experiment with a fairly effective mold release, melt one part paraffin wax (by weight) then stir in 3 parts mineral or baby oil. Best used when hot and liquid, but if applied ot the molds when cold (as a soft paste) use a stiff brush to ensure thin and even application, otherwise inconsistencies can mar the smoothness of the finished soap.
