PSA: Foolproof Stuck-Ferment-Fixer

[Evan!]

I get stuck fermentations here and there. It's just in the course of business. Not often, but once in a good while. Doesn't matter how big the starter is, how much I oxygenate the wort, sometimes the yeast will just poop out a little too high. Dumping dry yeast on it never helps. Even making a starter from a liquid culture and dumping it at high krausen has never worked for me.

So couple months back I ended up with a Saison that finished at 1.017...way too high. I tried raising the temp, rousing the cake, nothing. Just by happenstance, I had a Forbidden Fruit cake from a witbier sitting there waiting to be washed and harvested, so I dumped the Saison on that cake. Bam, a couple days later I was at 1.010!

So last weekend I brewed a Southern English Brown with a nice healthy starter of WLP002. It pooped out around 1.020 3 days later. Well, I thought, now's a good time to test out my hypothesis. So I had a batch of a very simple ale that I fermented with S-05 and it was highly attenuative (will one day be a kriek) that was ready to be racked. Last night, I racked it off the cake and racked the SEBA onto it. As expected, this morning, there's a nice little mini-krausen and some airlock activity.

So there's my PSA. You got a stuck fermentation? Just wait until you have a healthy cake (meaning, that beer attenuated fully with it), and dump the stuck beer right on top of it. I'm batting 1.000 so far...and I'll keep updating this thread if I have any future experiences with the technique.

EDIT: I'm not taking credit for this technique, it's nothing new, I just wanted to start a PSA thread for everyone to see. Credit for giving me the idea in the first place goes to ColoradoXJ13!

 

[Special Hops]

Nice tip! Thanks

 

[david_42]

And it's a good excuse to make another quick batch.

 

[Evan!]

And it's a good excuse to make another quick batch.

WHOOO, you ******* right. :rockin:

 

[Glibbidy]

Nice tip. I'm presently dealing with my very first stuck fermentation myself.
Anyone got a nice healthy yeast cake I can dump my imperial pilsener on?

 

[Evan!]

Nice tip. I'm presently dealing with my very first stuck fermentation myself.
Anyone got a nice healthy yeast cake I can dump my imperial pilsener on?

bes' git brewin!

 

[Desert_Sky]

do you really get stuck fermentations that often?

 

[bradsul]

That's a great technique I've used before as well.

But did you really consider it stuck after only 3 days or did I read that wrong?

 

[Evan!]

do you really get stuck fermentations that often?

Not that often, but yeah, here and there, like I said. I'd say 95% of my beers finish fine, but there are just those times when it happens. No rhyme or reason. I use big 2L starters, I oxygenate correctly with pure 02, it's just, sometimes, the yeast says, "ah, screw this, I'm going to sleep".

That's a great technique I've used before as well

But did you really consider it stuck after only 3 days or did I read that wrong?

You read correctly, sort of. Fermentation pretty much stopped after 3 days. It was going strong, then the krausen dropped, airlock activity subsided, and I took an SG reading. 1.020. Took another one last night (3 days later) and it hadn't changed. The yeast had flocculated into a compact cake (you know, that nice, highly-defined line between the cake and beer), the top of the beer was smooth as glass, and it was done. I've lorded over enough fermentations to know when they've finished, but my SG reading confirmed it.

 

[bradsul]

You read correctly, sort of. Fermentation pretty much stopped after 3 days. It was going strong, then the krausen dropped, airlock activity subsided, and I took an SG reading. 1.020. Took another one last night (3 days later) and it hadn't changed. The yeast had flocculated into a compact cake (you know, that nice, highly-defined line between the cake and beer), the top of the beer was smooth as glass, and it was done. I've lorded over enough fermentations to know when they've finished, but my SG reading confirmed it.

Gotcha, thanks for the clarification!

 

[ColoradoXJ13]

so where'd you get that idea...

http://homebrewtalk.com/showthread.php?t=61314&highlight=yeast+cake

 

[eschatz]

Thanks for the PSA. Duely noted.

 

[Evan!]

so where'd you get that idea...

http://homebrewtalk.com/showthread.php?t=61314&highlight=yeast+cake

Sorry, I didn't mean to imply that I came up with the idea, I'd forgotten that you'd suggested it...I just wanted to put a PSA thread out there to help people who didn't happen to see my Saison thread.

Duly noted, duly changed. Thanks, brother!

 

[MrFebtober]

I'm not sure I understand how this is different than making a new starter of S-05 and re-aerating the beer. Isn't that all that you are doing by dumping onto a yeast cake: aerating and introducing a new healthy yeast population? Or is there some cakey goodness aspect I'm missing? I guess it would introduce less water to use a cake over a starter, but also introduces more oxygen because of the transfer technique (unless you didn't literally mean "dump").

 

[Evan!]

I'm not sure I understand how this is different than making a new starter of S-05 and re-aerating the beer. Isn't that all that you are doing by dumping onto a yeast cake: aerating and introducing a new healthy yeast population? Or is there some cakey goodness aspect I'm missing? I guess it would introduce less water to use a cake over a starter, but also introduces more oxygen because of the transfer technique (unless you didn't literally mean "dump").

First off, unless you make a 5-gallon starter, then it's going to be less than your cell count here. I think it's the high amount of viable, ready-to-roll cells in one place that makes a restart much more likely. And no, I don't literally mean "dump", I rack of course. Reintroducing that much oxygen at this point will almost certainly give you problems with oxidation.

 

[Glibbidy]

bes' git brewin!

Catch 22. I can only lager ten gallons at a time. I best check on it tonight to see if it has dropped any in the past ten days.

 

[Evan!]

Catch 22. I can only lager ten gallons at a time. I best check on it tonight to see if it has dropped any in the past ten days.

how bout a steam beer?

 

[Glibbidy]

how bout a steam beer?

Now that is a brilliant idea. I'll have to check my schedule and see if I can fit it in.

 

[MrFebtober]

First off, unless you make a 5-gallon starter, then it's going to be less than your cell count here. I think it's the high amount of viable, ready-to-roll cells in one place that makes a restart much more likely. And no, I don't literally mean "dump", I rack of course. Reintroducing that much oxygen at this point will almost certainly give you problems with oxidation.

Gotcha. that makes sense.

 

[WBC]

Evan,
Do you always stay within the yeast fermentation recommended temperatures? Do you control temperature in a refrigerator?

 

[ColoradoXJ13]

Sorry, I didn't mean to imply that I came up with the idea, I'd forgotten that you'd suggested it...I just wanted to put a PSA thread out there to help people who didn't happen to see my Saison thread.

Duly noted, duly changed. Thanks, brother!

hey, no worries, just bustin' your balls.

I think the fact that the yeast cake is already acclimated to alcohol is a big factor too, whereas the yeast in a starter (usually pretty low SG) isn't all that used to it, that and cell count as you mentioned matters. Usually one is going to get a stuck ferment due to:

1) poorly attenuating yeast in a big beer (the 'saison' issue)
2) too small a starter for your beer
3) temperature problems
4) poor fermentability of extract/wort

the poor attenuating yeast problem can certainly be overcome with a nice hearty strain, as can issues 2 and 3, you are basically f'd if your problem is 4.

 

[Evan!]

hey, no worries, just bustin' your balls.

I think the fact that the yeast cake is already acclimated to alcohol is a big factor too, whereas the yeast in a starter (usually pretty low SG) isn't all that used to it, that and cell count as you mentioned matters. Usually one is going to get a stuck ferment due to:

1) poorly attenuating yeast in a big beer (the 'saison' issue)
2) too small a starter for your beer
3) temperature problems
4) poor fermentability of extract/wort

the poor attenuating yeast problem can certainly be overcome with a nice hearty strain, as can issues 2 and 3, you are basically f'd if your problem is 4.

Good points...though, at least with #4, if you're bottling, you won't end up with gushers or bombs, right?

 

[Evan!]

UPDATE: Not 2 days later, the SG is at 1.015, exactly where the FG for a SEBA should be.

triumphant again!

 

[ColoradoXJ13]

Good points...though, at least with #4, if you're bottling, you won't end up with gushers or bombs, right?

in theory...my first saison finished at 1.028, I bottled it, had no problems other than it being really sweet...

 

[MgMt_Home_Brew]

I've got a sort of old Rasputin clone sitting in a primary after 2 weeks(In know that it's only 2 weeks but the krauzen dropped and it looks done) the SG is 1.036. The OG was 1.114. I pitched 2 packets of US-05 dry yeast and was questioning if it was going to be enough.

Think I should try a starter tomorrow? Leave it for a couple more days then sample again to see if it moves? Or leave it, brew another small batch and rack on that cake?

This is the largest brew that I have done so I am just thinking I wasn't prepared with my measly 2 packets of dry yeast.

what do you think?

Edit: I have this sitting around 65-64 degrees

 

[thelorax121]

Nice, thanks for the tip

 

[Evan!]

I've got a sort of old Rasputin clone sitting in a primary after 2 weeks(In know that it's only 2 weeks but the krauzen dropped and it looks done) the SG is 1.036. The OG was 1.114. I pitched 2 packets of US-05 dry yeast and was questioning if it was going to be enough.

Think I should try a starter tomorrow? Leave it for a couple more days then sample again to see if it moves? Or leave it, brew another small batch and rack on that cake?

This is the largest brew that I have done so I am just thinking I wasn't prepared with my measly 2 packets of dry yeast.

what do you think?

Edit: I have this sitting around 65-64 degrees

Don't bother with the starter at that alcohol level. I'd bet a hunned dollas it'd do nothing.

What you need to do is brew a small, neutral ale with a yeast that has a high alcohol tolerance. Try an OG around 1.040. Ferment it out, let it clear, then rack this RIS onto it. Warm it up into the low 70's. See what happens. If nothing happens, then you just have a really high FG stout...with an RIS, that's okay.

 

[neumann]

Sorry to rouse a dead thread, but I just wanted to add another +1 to this tip. My Holiday Spiced Ale quit at 1.040 and I was ready to toss it. I had a Pale Ale that just finished. I gave this a shot and 24 hours later my gravity is down to 1.020 and falling. So, ya, just my little +1.

 

[claphamsa]

woa! coincidentaly I have a wee heavy sitting at 1.040... and a fully (over) attenuated APA in a bucket.........

 

[neumann]

Go for it. What I had wasn't worth drinking so I had nothing to lose. Don't know about you.