Side effects of adding new yeast to a stuck fermentation?

[JonBrew]

Hello all,

Yes, sorry, I know, another stuck fermentation thread.

Basically, I've had german ale stuck on me for about three weeks now. My SG was 1.041, TFG 1.010 and i'm stuck at 1.022. I've tried all of the following repeatedly:

- swirling/rousing yeast
- increasing temp
- wrapping fermentor in towels etc

Nothing has worked and my gravity is still reading 1.022. I know it's considered controversial but I'm thinking about adding more yeast.

Why is it so frowned upon?
I've done it before with another brew - it worked and the beer ended up tasting OK, not great to be fair but still OK.
What are the possible consequences?

Also, I've heard a few folk talk about "sleeping" yeast and that it can take up to 7-8 weeks for beers to fully ferment. Is this true? If so, should I Just play the waiting game? Anyone had any experience with this?

 

[AerationStation]

Generally the reason people look down on the practice of pitching new yeast is that if the beer is pretty far along it doesn't make the best environment for new yeast. There is isnt as much sugar as the yeast would like and the alcohol already in solution will stress them even more.

If you're going to do it you'll want yeast that are already in fighting shape and ready to go. You can pitch a starter at high Krausen to make sure you've got the best yeast you can.

Another thing to think about is the kind of yeast. For beers with larger chain sugars (ie ruffinose, maltotriose) that are keeping the sg high consider pitching a lager yeast at high Krausen. They are more apt to chew away at those longer chain sugars than ale or champagne yeast.

Sent from my SCH-I535 using Home Brew mobile app

 

[scottballz]

Generally the reason people look down on the practice of pitching new yeast is that if the beer is pretty far along it doesn't make the best environment for new yeast. There is isnt as much sugar as the yeast would like and the alcohol already in solution will stress them even more.

If you're going to do it you'll want yeast that are already in fighting shape and ready to go. You can pitch a starter at high Krausen to make sure you've got the best yeast you can.

Another thing to think about is the kind of yeast. For beers with larger chain sugars (ie ruffinose, maltotriose) that are keeping the sg high consider pitching a lager yeast at high Krausen. They are more apt to chew away at those longer chain sugars than ale or champagne yeast.

Sent from my SCH-I535 using Home Brew mobile app

Everything this man said is right on the money. This is why I always do a starter the day before. The extra equipment, flask and stir plate, is well worth the money in my opinion.

 

[JonBrew]

Thanks to all.

Anyone actully had any experience of "sleeping" yeast, i.e. yeast that have stopped working then came back into action weeks down the line without intervetion?

 

[eastoak]

Hello all,

Yes, sorry, I know, another stuck fermentation thread.

Basically, I've had german ale stuck on me for about three weeks now. My SG was 1.041, TFG 1.010 and i'm stuck at 1.022. I've tried all of the following repeatedly:

- swirling/rousing yeast
- increasing temp
- wrapping fermentor in towels etc

Nothing has worked and my gravity is still reading 1.022. I know it's considered controversial but I'm thinking about adding more yeast.

Why is it so frowned upon?
I've done it before with another brew - it worked and the beer ended up tasting OK, not great to be fair but still OK.
What are the possible consequences?

Also, I've heard a few folk talk about "sleeping" yeast and that it can take up to 7-8 weeks for beers to fully ferment. Is this true? If so, should I Just play the waiting game? Anyone had any experience with this?

was this an extract beer or all grain? what kind of yeast?

 

[ncbrewer]

Thanks to all.

Anyone actully had any experience of "sleeping" yeast, i.e. yeast that have stopped working then came back into action weeks down the line without intervetion?

I haven't had this experience, but I wonder if it might have happened to someone because it got too cold, and then warmed back up.

 

[JonBrew]

was this an extract beer or all grain? what kind of yeast?

All grain BIAB. Kolsch ale yeast.

Watcha thinkin?

 

[Thedutchtouch]

but what temp are you fermenting at? that yeast likes 65-69, and doesn't handle dropping into 60 or below too well

 

[JonBrew]

66 - 69. variable cause I've not got any temperature control.

 

[morticaixavier]

I haven't had this experience, but I wonder if it might have happened to someone because it got too cold, and then warmed back up.

one of the saison yeasts (I think dupont) is famous for this. turns out (per whitelabs) if you run the whole ferment at like 90*f it won't stall but otherwise it will. I haven't tried it because I hate fusels. but yeah, yeast will drop out because it gets to cold and then they can become active again later.

 

[eastoak]

All grain BIAB. Kolsch ale yeast.

Watcha thinkin?

that if it was extract it may have reached it's limit but that's not the case.

 

[morticaixavier]

hydrometer or refractometer? either way has it been calibrated?

 

[morticaixavier]

also, mash temps and was the thermo calibrated.