First question: Are you leaving the sediment behind in the bottle? If you're pouring the sediment in, you're pouring in a bunch of yeast, and that will cloud up the beer VERY quickly. If you're leaving the sediment behind, and it's actually the beer that's cloudy, not a bunch of extra yeast, then it's chill haze.
Chill haze is something that plagues even many pro brewers. It's proteins that dissolve at higher temperatures, but start to come out of solution at lower temperatures.
There's a few ways to handle it:
-Quick chilling after the boil will help, but sometimes that isn't enough
-A number of different finings that will help, from kettle fininings like Irish Moss or Whirfloc, to stuff like Isinglass or PVPP or Brewer's Clarex. Each work in different ways at different times.
-Normally, just enough time when cold will cause it to the haze to drop out on its own.
Worth noting that when using something on the post-fermentation end (like filtering or Isinglass, gelatin, whatever), it helps to have the beer cold (near freezing). If you filter at one temp, then chill it down more after that, you'll still get haze. The filtering will only remove the proteins that came out of solution at the warmer temp, but won't touch the stuff that's still dissolved, only to show up when you cool it down further.
Not at expert by any means, but that's my understanding at least.
For me, if I want a really clear beer, I use Whirfloc at the end of the boil, chill as rapidly as I can, give the beer at least 3, usually 4 or 5 weeks in the primary fermenter, rack it to secondary, chill it down further (I can go to about 40F in my swamp cooler) for another month, and in the very last week of that period, hit it with gelatin while it's already cold. If you or anyone who drinks your beer is a vegetarian, that's not going to be doable. But it makes for beer that's almost up to a filtered level of clarity.
