Slow fermentation

[lyacovett]

OK, this is not a stalled fermentation thread, or anything of the sort. I have a question about my "slow" fermentation though.

I pitched s05 in a batch at 1.060 11 days ago. Fermentation kicked off quickly and the airlock continued for 9 days, then slowed down and stopped. So I checked and there was still a krausen. It has been almost 2 weeks, and I still have a krausen, the gravity doesn't seem to be dropping any more, it seems to have quit at 1.011.

My question is this. I top cropped at high krausen. Could this possibly have something to do with the krausen not falling yet? The active fermentation process has appeared to quit, but I still have a krausen, it has receeded some, but doesn't seem to be dropping any farther. If after another week it hasn't dropped, is it ok to keg?

 

[TipsyDragon]

right off hand i would say you have head not krausen. its been what a total of 3-4 weeks now and your gravity has stopped falling. fermentation is done. allot of people on here wait 6 weeks before bottle/keging. you can keg now if you like.

 

[Revvy]

Interesting point you brought up about high krausen yeast. Are you saying that the yeast you pitched was from the yeast you cropped at high krausen?

We may be having a similar issue.

I have a wit beer that I pitched yeast over two weeks ago (Dec. 26th), that STILL has a 2" krausen on it. But on Saturday I took a grav reading and it had reached terminal gravity, 1.010.

The yeast I pitched was from bottle harvested hoegaarden yeast. I had capture the yeast from a dozen bottles back in late summer and jarred a bunch of it. Then a few days before brewday on this wit, I made a starter with two mason jars worth of the yeast.

I just realized from your post that it was one of only two times that I actually was able to pitch the starter itself at high krasuen.

And almost immediately it formed this huge, rocky krausen. And like I said, and over two weeks it still has it, though I'm at 1.010, AND the hydrometer sample actually tasted like the other time I brewed this recipe.

I am going to wait my whole normal month in primary, and then probably go ahead and bottle, the thing is, if it doesn't fall, the krausen should float on top of the beer as you are racking and as the volume lowers in the primary.

The thing is, I am wondering if it will be worth it to wash this yeast. If I it's so lowly flocculating in this first generation, won't that mean all generations will be low flocullating as well?

I wonder if I can mutate it with a high flocculating strain somehow.

 

[Revvy]

right off hand i would say you have head not krausen. its been what a total of 3-4 weeks now and your gravity has stopped falling. fermentation is done. allot of people on here wait 6 weeks before bottle/keging. you can keg now if you like.

Head in a fermenter???? THere's no such thing.

 

[TipsyDragon]

well Revvy. if i understand you, you harvested yeast from a bottle conditioned beer. right? i may be wrong here but those yeast are some of the least flocculating yeast out of what ever strain was used to brew the beer. so when they multiplied they of course passed those low flocculation genes onto the next generation of yeast. but seeing as people harvest yeast in this way all the time i cant see it being a real problem.

 

[TipsyDragon]

yea thats what the foam part of the karusen is. when you pour your beer the CO2 bubbles up creating the head. when you ferment the yeast produce CO2 that bubbles up producing foam. its the same foam in both cases. there is just more junk in the karusen.

 

[Revvy]

yea thats what the foam part of the karusen is. when you pour your beer the CO2 bubbles up creating the head. when you ferment the yeast produce CO2 that bubbles up producing foam. its the same foam in both cases. there is just more junk in the karusen.

I hate to say buddy, but I totally disagree with you on this concept. Part of the action of "heading" comes from the actually pouring of the beer into a glass, which also reacts with any nucleation sites/flaws on in glass, which releases the co2 and also reacts with any head specific proteins in the beer itself that comes from certain head specific grains or adjuncts (like wheat and carapils/dextrins).

Pretty much anything in primary will either be a krausen the remnants of a krausen or a pellicule.

you harvested yeast from a bottle conditioned beer. right? i may be wrong here but those yeast are some of the least flocculating yeast out of what ever strain was used to brew the beer. so when they multiplied they of course passed those low flocculation genes onto the next generation of yeast. but seeing as people harvest yeast in this way all the time i cant see it being a real problem.

I think you may be on the money here. IIRC you are right about bottle yeast being the least flocculant of yeasts. And it being a big harvest from lots of bottles, prolly just magnified that characteristic in the yeast.

But I am still wondering if catching a yeast at HK, whether it's cropping it, or pouring a starter at HK, means we are catching the little buggers at a certain point in their "cycle." Like before the flick on the "flocculate now" genetic switch.

And so we are catching that switch in the off position and reproducing it?

It's interesting to say the least.

Thanks for you insight tipsey,

 

[lyacovett]

yeah, I am probably going to just have to keg thorough the krausen. the funny thing is, I top cropped from this batch, and did starter right away. The starter went from 1.060 to 1.010 in 2 days on the stir plate, and completely dropped out. The krausen reformed in the primary after the harvest in about an hour, so I'm thinking maybe some less flocculant yeast got in the krausen the second time ??? who knows .....

 

[Revvy]

yeah, I am probably going to just have to keg thorough the krausen. the funny thing is, I top cropped from this batch, and did starter right away. The starter went from 1.060 to 1.010 in 2 days on the stir plate, and completely dropped out. The krausen reformed in the primary after the harvest in about an hour, so I'm thinking maybe some less flocculant yeast got in the krausen the second time ??? who knows .....

Can you cold crash? I can't unless I open a window and stick it on the connecting roof of my loft. But cold crashing SHOULD pull the krausen down. I would think.

AND have you simply tapped on the side of the fermenter? That might knock it free.

 

[TipsyDragon]

if the yeast have the low flocculate gene it wont matter when you pitch them. when the "flocculate now" switch does get flicked on it will still be on low.

now you may be able to sway the yeast culture back the other way toward the high flocculation end by harvesting yeast out of the bottom of the yeast cake in the primary. in theory these where the first to flocculate and have the better genes.

 

[Revvy]

now you may be able to sway the yeast culture back the other way toward the high flocculation end by harvesting yeast out of the bottom of the yeast cake in the primary. in theory these where the first to flocculate and have the better genes.

That may be a good idea.

I gotta tell you it's made for a clean tasting hydro sample and a beautiful tasting wit.

Funny before this discussion this morning I actually had considered top cropping this yeast.

If i end up racking under the krausen, I may try to use my auto siphon and pull up as much of the bottom yeast as possible so as not to get much of the top stuff.

Thanks tipsy & lyacovett for this great discussion. :rockin: