Casting soap is much easier than you might think, and the results are beautiful! Soap pulp melts at 54°C, either in a water bath on the stove or carefully in the microwave. It is important to keep a close watch on soap pulp so that it does not begin to boil or bubble. If you use the microwave, heat on high for 10 seconds at a time (5 seconds once it's started to melt) and stir until the pulp is completely melted. Add colour and scent to the pulp before pouring into the mould. Attach soap stamps to the mould with melted soap pulp, with the design facing inwards.