Cold break is the material that falls out of your wort when it chills. You can leave it in the pot or dump into the fermenter. Opinions vary. Yes you can clear a beer with gelatin. Buy the clear Knox gelatin from your grocery store. Put half a packet into 1 cup of warm water. Let it sit for 15 min and then almost bring to a boil. Do not boil!! Then add to your beer (works better when added to cold beer) a couple of days before you bottle or when you keg.