Home made play dough will crystallise because it has salt in it. Commercial trademarked stuff? Who knows? The manufacturer refuses to let anyone know what's in it. Could be toxic or a carcinogen or cause autism for all anyone knows. read more
According to the manufacturer, Play-doh is made of flour, salt, and water. Apparently, under certain conditions, Play-doh can dehydrate, causing the salt within it to crystallize. read more
I was cleaning up my room, and I found some old Play-Doh I used for a project once. I opened the Play-Doh and it had crystal-like spikes sticking out of it, and sugary crystals growing on the top. read more
PLAY-DOH crystallizes because of one of its ingredients which is salt. Crystallization can be prevented by storing the compound in a cool and dry place. read more