dry ice is gonna freeze it,no need to freeze extra. shake the bag with ice and fresh material in it for a minute or so and filter through. letting it dry before making hash will bring other green parts into your hash. best way to make dry ice hash and get pure resin is to make it directly after cutting without drying and putting it to freeze. trichomes get separated from buds and leaves quickly and no green parts mix into it.Works great for me. pre-freeze might create mold, I would avoid that.