Is this a new batch of aspen, or is it your infested aspen? If you haven't already, ditch the old stuff. I've personally never baked aspen, but if you freeze, definitely don't moisten!! Otherwise you'll end up with a sloppy mess when it thaws lol. I used to freeze my aspen, but don't any more. Not worth the hassle IMO. Never had a mite problem either *knock on wood*.