Fermentation radically stopped after ~72 hours

[Plasse_D]

Hello everyone,
Last weekend, we brewed 40 litres of a farmhouse type beer. 20 litres went into a glass carboy and the other 20 litres went into another identical glass carboy. In each we pitched 1 vial of WLP670 American Farmhouse blend from White Labs (http://www.whitelabs.com/yeast/wlp670-american-farmhouse-blend). We ferment in a freezer with a temp controller at 21C/~70F. Each carboy is rigged with a tube thus creating a blow off (the other end of the tube ends in a 1 gallon water filled jug). OG of the beer was 1.060 /*14.7 Plato.

After 12 hours, the fermentation was going top notch. Good esters were coming from the carboys. Bubbling, activity, movement, everything norma (I’ve been brewing with this "method" for ~2 years). After 48 hours, fermentation was still going A1. See picture 01.jpg.

After 72 hours, one of the carboy seemed to be "dead". No more foam head. No more bubbles coming from the end of tube. Almost no activity/movement in the carboy (see pictures 02 and 03.jpg).

Anyone ever had this or something similar happening to them? What should I do? Should I try and restart the fermentation? Should I measure the gravity to see what happened? Thanks.

 

[Yooper]

Yes, that happens every batch. Fermentation gets active, then finishes up. When it finishes up, the krausen drops and the beer will start to clear.

 

[BrewKnurd]

Yes, that happens every batch. Fermentation gets active, then finishes up. When it finishes up, the krausen drops and the beer will start to clear.

Well sure, all batches stop... but this one radically stopped!

Sorry, OP, I couldn't resist. But you're fine. If you like, you can take a sample and check the gravity to verify, which you should do at some point before packaging anyway.

 

[Plasse_D]

Thanks guys. Like I said, I’ve been brewing for a bit more than 2 years ; I know fermentation stops at some point...

The thing that bothers me is that one carboy (of the same beer, same yeast, etc.) is still fermenting strong while the other is completely "dead". That does not seem strange to you guys?

 

[Plasse_D]

Correction : I should have said after ~55 hours. Not 72 hours the fermentation stopped. It’s kinda fast (too fast), don’t you think?

 

[BrewKnurd]

The thing that bothers me is that one carboy (of the same beer, same yeast, etc.) is still fermenting strong while the other is completely "dead". That does not seem strange to you guys?

Given that you pitched different vials of yeast that could have had significantly different viabilities into the carboys, that does not seem particularly strange.

Correction : I should have said after ~55 hours. Not 72 hours the fermentation stopped. It’s kinda fast (too fast), don’t you think?

Nope.

BTW, given that you're dealing with a farmhouse yeast, its quite possible that fermentation isn't done, even if it looks like it. Farmhouse/Saison yeasts have a tendency get off to a rocking start and then take a good long while (looking like they're not doing much) to get to FG.

 

[Plasse_D]

Thanks a lot BrewKnurd! Appreciated.

Do you think we should blend the two in one 45 litres carboy? The problem is that carboy does not fit in my temp-controlled freezer and temp will be oscillating from 16C to 18C (it’s in my basement). So we’ll loose the 21C , which I guess is not the end of the world once the "big krausen" part is over? Is it?

 

[BrewKnurd]

Thanks a lot BrewKnurd! Appreciated.

Do you think we should blend the two in one 45 litres carboy? The problem is that carboy does not fit in my temp-controlled freezer and temp will be oscillating from 16C to 18C (it’s in my basement). So we’ll loose the 21C , which I guess is not the end of the world once the "big krausen" part is over? Is it?

I would not advocate cooling down a farmhouse yeast that's past the most active stage of fermentation. If anything, this is the time frame where you'd want to start slowly raising temperature to help it finish out.

 

[duboman]

I would not advocate cooling down a farmhouse yeast that's past the most active stage of fermentation. If anything, this is the time frame where you'd want to start slowly raising temperature to help it finish out.

Definitely ^^this^^
Begin raising the temp, even as high as mid 80's. these strains like heat and helps them finish in a more timely manner

 

[kh54s10]

It looks to me like you have 2 different sized carboys there. If they are different, and you could not pitch a precise amount of equally viable yeast samples I would not be surprised that they fermented differently. The only way you will know if the one stalled or finished too early would be to take and compare gravity samples. I would wait until 10 days or so.

 

[Plasse_D]

Again, thanks a lot guys!

Okay, this is kind of a weird work around but what if I blended the two carboys in my big carboy than re-separate them in my 2 20litres carboys and put them back at 21C/70F. That should help?

 

[kh54s10]

Again, thanks a lot guys!

Okay, this is kind of a weird work around but what if I blended the two carboys in my big carboy than re-separate them in my 2 20litres carboys and put them back at 21C/70F. That should help?

I definitely would NOT do this. Way too much chance of making things worse. Infection, oxidation etc.

I would work more to determine that you actually have any real problem before taking any action.

 

[BrewKnurd]

Again, thanks a lot guys!

Okay, this is kind of a weird work around but what if I blended the two carboys in my big carboy than re-separate them in my 2 20litres carboys and put them back at 21C/70F. That should help?

Help what? You haven't identified any actual problem. And unless you have an actual problem, what's the point of trying to fix it?

I just don't see what positive this would accomplish.

In other words, what kh54s10 said. Since I'm just now reading that he basically said the exact same thing. But since I've taken the time to write it, I'm posting it.

 

[Plasse_D]

kh54s10 : I have two identical 20 litres carboys and also one 45~50 litres carboy that can hold the two 20 litres.

I thought that mixing the two together could help "re-launching" the dead carboy. Surely, I’m aware that there are risks of also mixing infection, creating oxydation, etc.

So, yes, I’ll start by taking a measure tonight when I get home. There’s also a chance that I can taste/smell if there’s any infection going on.

Thanks a lot guys, very appreciated.

 

[BrewKnurd]

I thought that mixing the two together could help "re-launching" the dead carboy. Surely, I’m aware that there are risks of also mixing infection, creating oxydation, etc.

But this is all still based on the premise that the "dead carboy" needs "re-launching". I've not seen anything that supports that premise in any sort of conclusive way.

 

[Plasse_D]

But this is all still based on the premise that the "dead carboy" needs "re-launching".

Yep. I totally get it! Thanks.

 

[Plasse_D]

So I just took a measure. 73F and gravity reads 1.01
I guess it just went really fast! Tastes good (like a young beer usually tastes : lots of rough yeast aromas/flavors and lots of rough cereal flavors).

Cheers!

 

[isac777]

Finishing fast aint always bad. Heheheh

Couldnt resist "softball"

 

[Plasse_D]

finishing fast aint always bad. Heheheh

couldnt resist "softball"

:d