i think i was reading in the joy of home brewing that the brown stuff contributes to the fusel alcohols when it drops back in the beer, but you're risking contamination too much if you try to get it out.
Yeah well the Joy of Homebrewing was written over 20 years ago...it's a good resource for basic stuff, BUT a lot of the science of brewing has evolved.....it evolves every day...
When that book was written rinsing with bleach was thought to be the state of the art in sanitization...
Leave the krausen to fall and it will help scrub your beer clean especially if you leave your beer 3-4 weeks in primary...
Unless a book gets constantly updated it only represents the author's and the common knowlegebase at the time it was written which could be at the minimum 3, or even 10 or 20 years old. It's simply a snapshot, not a "holy text" unchangable (even Holy texts aren't unchangeable, btw) and far from perfect.
If the author doesn't revise it, or if he writes a sequel and no one reads it, then that doesn't mean that the NEW info doesn't exist or that the author still believes what he had originally written...
The thing with the internet and podcasts is that the author might have actually said he was wrong about something, or learned something new that renders what he originally wrote no longer valid, and it might have happened only yesterday...So the common wisdom has not caught up with it unless someone like me who tries to keep up with everything new and constantly tries to learn as much as he can reports it back to you...case in point...
Didja know that John Palmer has retracted most of what he wrote about IBU's in How To Brew?
He attended a high end academic conference on hops that totally blew away he felt what he wrote in the book....And he did an entire basic brewing podcast on it..