Thicker mixtures may have to be ladled in. Tap the mold onto hard surface to break any air pockets that may have formed. Fill as completely as possible without overflowing and allow to film over. Once the soap is frozen solid, pop them out onto plastic canvas drying rack and leave to cure for at least two weeks. Sometimes longer for larger molds.
Check bars about once a week.
If they've warped, turn them over. Some soaps will not need to be turned. I have chosen my favorites and those that may be more likely used medievally. Add the sand and pumice and stir until thick. This will sink unless you stir continuously and until rather thick.