Leaves are burning right now. It is definitely one of beautiful season in Rochester.
Thermal shock. If you pour water in ice cube, it cracks. It is similar to that. Sudden change of temperature makes the clay and the glaze to expand, if their rates are not the same, it cracks.
If you throw the pot unevenly, it may causes the thermal shock. If the clay and glaze do not fit, the properties of the clay, list goes on. It is good idea to put a spoon (metal) in a cup when pour the hot boiling water, and start with the cold oven. I usually put a dish in 355F oven as long it is room temperature (not from fridge), though. I read somewhere that 400F is too hot. I stop making the pie dish long time ago, as everyone bakes differently, and sometimes it broke beyond my control, but I replaced them anyway.
I am testing a white glaze recently. I used to use the Vivika’s white glaze until I start using the white stoneware and it started to crazing. I am not sure how I am going to apply it. This glaze does not show any crazing on the current clay.