During these cold weather months we frequently get questions about what happens to moist clay if it freezes. Clay that freezes isn't ruined, but it needs a lot of work before it can be used again. The thawed out clay needs to be wedged very, very well or run through a pug mill to make it usable.

When moist clay freezes and thaws, the physical water in the clay becomes unevenly distributed. Some parts of the clay will be dry and other parts will be mushy. The clay needs to be re-mixed to even out the distribution of water. Additionally, the expansion of the ice within the block slightly separates the tiny clay platelets leaving small fissures in the clay. If the thawed out clay is used without remixing, the object that is formed will develop a series of cracks.

It is best to keep your clay warm, but if your clay freezes, or even just gets a little frosty on the surface, don’t toss it out, just wedge it up really well and you’re good to go.

Bonus tip: Frozen glazes are typically fine to use if they are remixed and sieved after the glaze has thawed out.