I don't understand how conicals work...how do you get the trub and yeast out? I understand it collects at the bottom, but how do you remove it without dumping your beer at the same time? Do you just let it out a little bit, real fast or something? And when you open it up, air has got to get in...doesn't that disturb the trub? I know when someone explains it, I'll feel stupid, but I just don't get it.