Here you see bone dry clay being broken up with a hammer. This clay comes from one of my ‘scrap’ buckets and has dried out. I have some clay that is still in the original plastic bag that it was shipped in years ago and has dried out. The nice thing about clay is that it has no expiration date; afterall, it laid in the ground for a couple million years first! I break my dried clay into chunks about 1/4″-3/8″ in diameter. When you do this, always were a respirator approved for clay dust and do it in a well ventilated location.