What and why is this thick hard "krausen" on top after fermentation finished?

[Metalhead_brewer]

Hi everybody this is the second time it happens, fermentation has stoped and this thick "krausen" layer apears on top is not foamy, is harder and compact than normally, beer has a odd flavor and smell that increases with time becoming undrinkable, is not soury is more like strong fermented flavor, it happened twice now one time with a kolsch and this time with a cream ale both light and almost hopless beer one with a s-05 and other with k-97 both have been made before but with good results nice, clean and crispy flavor, oh and both with more than 2 weeks to finish fermentation and higher FG. Any idea of what is causing this?

 

[hotbeer]

Yeast.

And perhaps some other stuff that will or would have eventually just been trub on the bottom or stuck to the sides in the headspace.

I'm thinking you pitched a lot of yeast.

 

[balrog]

Use same process as before? Reusing yeast? What temps? Leaving it alone or checking it by opening the bucket lid every 34 seconds?

As a living thing, yeast gonna do what yeast gonna do. I've had hard sludgy krausens on different yeasts before, just stick the autosiphon into the clear beer between the krausen and the bottom sediment and rack away.

 

[Metalhead_brewer]

yes everything is same process and beer is clear but the poblem is that weird smell and flavor it gets, first time it happened i just kegged it but with time (2-3 weeks) that smell and flavor increases and becomes undrinkable.

 

[hotbeer]

Weird smells are what you want to be coming out of the beers while they ferment so they don't stay in it to smell when you drink them. The weirdness depends on recipe and other stuff.

Though I've never had as thick a crud layer on top of mine, I don't see anything that you should currently be concerned with other than the possibility you are opening the fermenter too much which might possibly result in infection.

Regardless, once it's in the fermenter, I don't know anything you can do to save it if it is infected. Just wait till the hydrometer shows it's at FG along with some amount of additional time to clean itself up and then bottle/keg it and see whether it's good beer or bad beer.

What yeast and how much did you use? Fresh or several brews old slurry from the bottom of your other batches?