Krausen scum didn't blow off

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?

Sounds like most fermentations to me. When the krausen falls, I always get gunk floating on the surface for a good week afterwards. It falls back in and the solids eventually settle out in the yeast cake.

Dunno about the astringency, but fermenting beer can have all kinds of odd smells and tastes as it's going. If it's not jumping out and smacking you in the face, odds are it's fine.

I'd let it sit in the primary for another week and then start taking hydrometer readings... Once it doesn't change it's time to rack and bottle.

Okay, so I sounds like this is a pretty normal event. My first batch blew off hard, and by the time it settled all the krausen was stuck to the sides and the beer surface was clear.

I know beers can have all kinds of weird flavors in the middle of fermentation and I normally wouldn't be so paranoid. It's a combination of the fact that I know I have one of the bad packages of Nottingham sitting in there, and this beer is supposed to be a gift to a good friend's father at his wedding reception, so I want it to be a good product.

Now that I think about it, maybe it is just because the krausen scum is beginning the process of traveling down to the trub on the bottom. I guess that would cause a temporary increase in astringency until it all settled down.

I think the lesson I need to take from this is to quit tasting it. For now I'll just let it sit and forget about it for a week. Thanks for the reassurance.

Yep, sit it and just check your temps. come back in a week or two or three and then start checking the gravity. Just brew another two or three batches and that will keep you busy enough that you won't want to keep tasting and checking on it all the time.