How long should krausen hang around?

[philistine]

Hey all,
I've got a batch of a blonde wheat which has been in the fermenter since last Saturday. I used white labs 300 yeast which I'd made into a starter the night before and fermentation and healthy looking activity started within about 4-5 hours of pitching.
The fermenter was initially kept at about 22c for the first 2-3 days but then I was able to move it into a controlled temp and brought it down to a very consistent 18c and it's been sitting on exactly 18c ever since.
The thing is, there is still a decent layer of krausen on the brew and I would have thought that after 8-9 days it would have almost gone. I'm still pretty new to all this so maybe this is normal, but the last few batches I've done have all settled down and looked "flat" after 4-5 tops (although they were all small 5l batches made with extract - this is 20l partial mash)
Is it possible that the ferment has stalled?

 

[Midnight Brew]

I doubt the ferment has stalled its more then likely finished but test with a hydrometer to be certain over at least 2 days.

WLP300 being a german hefe strain would be a top cropping yeast. They throw big heads and like to party for several days after fermentation has complete on top of your beer. If you want it to settle out so you can package you can cold condition it for a few days in the fridge and it will all drop out.

 

[TimT]

Nah, wheat beer just forms a really really thick cloud at the top. After the first few days it's not really krausen anymore (since it's just the after result of active yeast - 'yeast woz ere'). Probably forms a good protective blanket, though. Your beer sounds fine, maybe do a gravity reading or two to see if it's finished fermenting or not?

 

[jaypes]

300 was a monster last time I used it, can hang around for 2 weeks. Dont let a krausen or lack of be an indication of fermentation - same goes with an airlock.

 

[philistine]

thanks guys, good to hear!