High krausen for 3 weeks

[jceg316]

3 weeks ago I made 20l of kolsch using safale K97. I took a gravity reading last week and it was close to 85% attenuated which for that yeast is done, but was really cloudy so thought I'd leave it another week for the yeast to clear up and flocculate. This is in a SS FV so I can't see inside, opened the lid today to have a look and there's still a lot of krausen going on. Seems odd it's still there after 3 weeks. Anyone else experienced something similar?

 

[Cestrian]

If you cool it to 12C and gently stir to break the krausen up, it will stick to the bottom of the fv like a pancake in 24 hours.
What temperature did you ferment at? I have just finished my second brew with this yeast over the last few weeks, both fermented at 18C and there was a strong smell of bananas at the end of the fermentation on both.

 

[MickDundee]

K97 has a weird thick Krausen that won’t go away until cold crashing even if fermentation has finished.

When I used it I’d read to tap the side of the FV with something and it will slowly sink.

 

[An Ankoù]

3 weeks ago I made 20l of kolsch using safale K97. I took a gravity reading last week and it was close to 85% attenuated which for that yeast is done, but was really cloudy so thought I'd leave it another week for the yeast to clear up and flocculate. This is in a SS FV so I can't see inside, opened the lid today to have a look and there's still a lot of krausen going on. Seems odd it's still there after 3 weeks. Anyone else experienced something similar?

Had a similar experience with Opshaug Kveik. It just wouldn't finish! The beer I made (a Simmonds Bitter) was fine with a touch of "sea breeze" about it and it's not over-attenuated, but I'm not sure I'll use that yeast again.

 

[Pennine]

ive read somehwere that it makes an excellent open fermenting yeast because of this.

ive used it a couple times but do not recall much about it. one of those things i keep meaning to do is sample yeasts side by side.

 

[jceg316]

Had a similar experience with Opshaug Kveik

I've used that yeast before for a doppelbock, took ages to ferment and eventually got stuck at ~1.022. I tried pitching some US-05 but it didn't do anything.

ive read somehwere that it makes an excellent open fermenting yeast because of this

I've read this too, and I found someone on another forum saying even though the krausen is there you can still bottle from underneath it. I will have to fact check this before I bottle. He also said the window for top cropping this yeast is very big, so I might try top cropping as well.

 

[An Ankoù]

I've read this too, and I found someone on another forum saying even though the krausen is there you can still bottle from underneath it. I will have to fact check this before I bottle. He also said the window for top cropping this yeast is very big, so I might try top cropping as well.

I've had a sachet of this knocking around in my yeast box for several years as I've never really known what to do with it. I think it's about time I gave it an airing. Any recommendations? I get the impression it's difficult to clear.

 

[jceg316]

I've had a sachet of this knocking around in my yeast box for several years as I've never really known what to do with it. I think it's about time I gave it an airing. Any recommendations? I get the impression it's difficult to clear.

The packet says suitable for wheat beers but the majority of reviews have said it's far too clean for that sort of style and is very similar in flavour to US-05, so I bought it for a kolsch. Upon doing extra research I think it was made for open fermentation of wheat beer styles as it seems open fermentations increase esters and phenols.

This post Review of Safale K-97 German Ale -- Great for Open Fermentation is probably the best source I've found so far; a homebrewer who seems to have used it a fair amount.

I've used this yeast twice before and both times it under attenuated. I did the usual: rouse the yeast, increase temp, but no more movement on FG so I bottled, but that seemed to get the yeast going again and I had bottle bombs. This time it's attenuated well though, not sure what the difference was.

 

[jceg316]

If you cool it to 12C and gently stir to break the krausen up, it will stick to the bottom of the fv like a pancake in 24 hours.
What temperature did you ferment at? I have just finished my second brew with this yeast over the last few weeks, both fermented at 18C and there was a strong smell of bananas at the end of the fermentation on both.

For some reason I completely missed yours and @MickDundee's message first time! Anyway, I've been fermenting at around 20c, it's not been temperature controlled but the room it's sitting in is a pretty stable temp. I've got a fridge set up now which I will stick it in once it's free.

 

[Cestrian]

I think the K in K97 is for kolsch. They’re meant to make a good altbier too. If I used it again I would ferment it cooler 15C to try and avoid that banana aroma. Hope that fades in the final beer.
I am getting an altbier on at the weekend, but I have got a WLP1007 starter on the go. It’s meant to be similar to K97 but cleaner.
It takes a while to clear up, so I’m leaving my last batch in the fridge for a month before I bottle it.
With regards to attenuation, my last brew seemed a bit slow so I stirred the krausen back in after 5 days, but checked again after 8 days fermenting and it had got down to 1012 from 1058.