My kiln will be 950? while I'm making beads and for a short time after the last bead goes in. Glass expands when it is heated and contracts as it cools. Letting the beads sit at this temperature removes any stress within the beads that can occur as different layers of glass are applied during the creation process. Once I'm done making beads for the day, I set the kiln to cool down at a controlled rate. This process is called annealing and ensures that the bead will not crack after it's made.