I wouldn't grind it, maybe let it thaw out in warm water and then smash it in a pestle and mortar? That seems like it would to the trick. it just depends though, if this is kava root straight out of the ground, still with all of its juices and enzymes in tact, just frozen, them I'm all in. But if it's just dried roots that are frozen and shipped, I'll pass. I'll try and contact rex with detailed questions tomorrow or so. If he is still selling it, I'll definitely be the guinea pig lol