Trub Question from 1st timer

[Piston Broke]

Hi
I have just left behind the kits ( except muntons smugglers which i thing is fantastic) after a year of quite successful brewing and am just into the 3rd day of a recipe from Graham Wheeler's British real ale book ( brakespears special). I have noticed that there is a load of black "stuff"/ dark folicles floating on the head.
It states in the book on page 77 to "skim these off tsking care to cause the minimum of disturbance to the head". My question is do i need to take it all off, if so i wo'nt be left with much head as its pretty much covered in it. If i don't skim what are the implications and thirdly do i need the head if the lid is on?

thanks

Nick

[soupdragon]

Hi Piston Broke

I presume you're talking about the " bits " that sit on top of the yeast during fermentation? You can leave them there but some of the more serious brewers may skim the crap from the top. One thing to think about is the more often you whip the lid off your fermenter, the more chance of introducing wild yeast and causing an infection. Generally speaking, yeast knows what it needs to do and if left to get on with it you shouldn't have too many problems

Cheers Tom

[Wolfy]

An active top-fermenting yeast will usually produce a rocky 'head' on-top of the fermentor, the active yeast will be a creamy colour.
Floating ontop of the yeast you may have darker brown/black flecks and flocks, these are often hop particles, and other proteins that have an undesired bitter-type taste, this gunk will often stick to the sides of the fermentor, or under the lid too.
Depending on your process and ingredients you may have a lot or a little of this material, and this is what the book is suggesting you remove, not all of the yeast that is floating and fermenting your beer.
If you do choose to remove the gunk, it should be done while the fermentation is active, and before the yeast starts to fall back into the beer, often this is 1 or 2 days after the yeast has been pitched.

I'm not sure of too many people that skim the gunk off, but the practice may be more wide-spread than I am aware, and it is suggested in the book.

To answer your other questions:
If you do skim, just take the thin layer of dark/brown/black stuff off the top, but try to leave the clean milky coloured yeast that is also there (at day 3 the yeast/head may already have started to fall back into your beer and it may be too late, just depends on the yeast and your fermentation).
If you don't skim some of that gunk will end up in your beer, its not something I have ever worried about, I have been more concerned with leaving the lid on the beer and letting the yeast do its own thing without interference or adding additional chances of infection.
Most of the foamy looking head should be milky-colourd yeast, so you do need it, skim the stuff off the top if you wish, but try to leave the bulk of the yeast behind (unless you wish to top-crop and save some for re-use).

[TC2642]

A lot of this will stick to the side of the FV when the transfer is being done, I personally don't bother skimming unless I have to i.e. the yeast head is coming out of the top of the FV, and have not seen any deterioration in flavour when I've had less aggressive fermentation and the head falls back into the wort.