Simple question. Does extract have a lot of trub like you would have in all grain brewing? I just hope the "trub" at the bottom of my fermenter is not undesolved extract.
If it was, the yeast would still find it an eat it. What's at the bottom is dead yeast, living yeast, dormant yeast, hop particles and anything else solid that yeast can't eat. Don't sweat it. Even in extract brewing you get a thick layer of trub.