I have heard that around 24 hours is best for stamping. Is this correct?
You may be able to stamp at 24 hours, it might be 7 days or even right out of the mold. Cold Processed soap is very individualistic and much of the, “Stamping Window” depends on the formula, amount of water, mold insulation, herbs, clays or additives to the soap formula, ambient air and humidity.
As you can see there are no set rules. I always suggest, systematic testing of samples, starting from right out of the mold to a week. Approach it as though you were a chemist running a series of tests.
The beauty of CP soap is the unique characteristics that you as the Soapmaker can impart to it. This does present challenges, because it is not as predictable as milled soap, forced through saponification, overcooked, mashed, crushed, dried, ground and then pressed into perfect bars.