You know how, when making a mel, you rack into the glass carboy and get maybe a few inches of crud up on top? Stays up there and the gas pushes through it. Eventually it useually falls to the bottom and starts circulating, but sometimes it gets stuck up in the neck of the bottle. Is there any reason to worry about this stuff in terms of being an environment for mold or such? Do you guys poke it down or leave it alone?