Pottery Making: How Does Bisque Firing Work? - as part of the expert series by GeoBeats. Clay goes through two firings as you finish it: the bisque firing and the glaze firing. So we will take our trimmed, and finished pots and when they are completely dry they are ready for firing. We can see the difference in color between the leather hard pot and a bone dry pot. This is important because if you load your damp pots into the kiln, as the kiln heats up, the water in the pots will turn to steam and you will have an explosion. Generally, bisque firings are not as hot as glaze firings which will allow the pots to get hard but still remain porous so that they will accept the glaze, and generally bisque firings are a slow heating up process because there is a lot of organic material in the clay that needs to be burned out so that you will have beautiful looking pots when you apply the glaze. So, into the kiln go the bone dry pots and after the bisque firing you will have hard pots that are now ready for the glazing step.