I brewed my second extract batch last Sunday: an Irish Red Ale. I pitched Nottingham into it that night, but became worried after there was no activity whatsoever the next morning. I started poking around online and found out I had used one of the bad Nottingham lots, so I repitched a package of Safale-05 that afternoon. By then there was some minor activity, but after pitching the second time it took off like it should.
The only problem was that the krausen only rose about 1/4 of an inch, and now that its fallen back down there's a layer of krausen scum laying across the surface of the beer.
I took a quick taste today and noticed an astrignent bite at the very back of the sip that definitely wasn't there two days ago. I'm worried that the bitter scum is beginning to diffuse back into the beer. Its in a carboy so I can't skim it off.
Are these two related as I seem to think? And if so what are my options? Primary fermentation has slowed down considerably in the last twelve hours and should be just about done, although I do need to take a reading today. Should I consider going ahead and rack to secondary if I'm near my FG and leaving the yeast cake and krausen scum behind?