Can greenware that has been frozen and then dried be fired?

Yes, greenware that has been frozen and then dried can be fired. This process is called freeze-drying or lyophilization and it is commonly used to preserve food and other perishable items. When greenware is frozen, the water content in the clay turns into ice crystals and the clay particles become less tightly bonded. This makes the clay more porous and easier to dry. When the frozen clay is then placed in a vacuum chamber and heated, the ice crystals sublimate and turn directly into water vapor, bypassing the liquid phase. This process preserves the shape and structure of the clay and prevents it from cracking or warping. Once the frozen and dried greenware is completely dry, it can be fired in a kiln.