Stalled Fermentation Options

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Rob2010SS

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I have a co pitch sour in the tank currently. I made the mistake of using OYL 011 as the yeast instead of my standard US 05 and it stalled at 1.041 when the expected FG was 1.027 (OG was 1.080). I'm trying to get it to finish. What I've done thus far...

1. Tried warming it up a bit.
2. Tried warming it up again and rousing the yeast by pushing a little CO2 in through the bottom dump port.
3. Added 5 packs of US-05 and warmed it up again to the max recommended temp for that yeast (75F). I did this on Wednesday night. No activity as of right now.

I know that I pitched that yeast into a hostile environment so I'm giving it till the end of the weekend before I call it and say that's not going to work.

My question: What are my other options to try and get this going again?

Now, this beer was going to get 20lbs of pureed fruit added after fermentation. I was thinking that MAYBE by adding that fruit and all that sugar, might kick off fermentation again. I know that's not guaranteed though and I could end up with a very sweet, fruited sour.

I also know I could make a large starter, let it get active and pitch that in. However, I question if that would work if pitching 5 packs of US 05 into 17.5 gallons doesn't work.

Any other ideas?
 
The other thing I forgot to mention is pH is at 3.3.

I suppose worst case scenario, it'll just be a tad sweet and only 5.2% as opposed to 7%. I mean, I could still drink that. I like sweet beers anyway... If 450 North can dilute product down to 3% and people like it, I think people will still like this!

(still open to other ideas if anyone has any)
 
A couple of thoughts:

Your ABV is around 5% right now. That’s not crazy high, but I’ve read that alcohol can shock the cells of young yeast. Option 1 would be to try pitching the s-05 with a starter....give the yeast a chance to acclimate to alcohol before just throwing it in.

It’s possible that your fermentable sugars aren’t available for sacchoramyces...but will be for the Brett. I think Brett can ferment other sugars that sacc can’t. Does your sour recipe include a Brett strain? brett can take a little longer.

I’ve had a stuck fermentation before and it can be a pain to figure out. Mine have always been high ABV beers though....never had a sour get stuck.

good luck!
 
There is no brett going in it. It was essentially a kettle sour with the souring done in the tank.

I thought about the starter as well but again, if 5 packs of yeast didn't do anything, not sure a starter would help. Then is be adding in that starter wort for nothing.

It's been roughly 4 days with no activity from the us05 yeast. I think we're going to take our chances with adding the fruit and see how it goes.
 
Firstly, how are you measuring gravity - refractometer or hydrometer? Refractometers don't work after fermentation has started because the alcohol skews the reading, so they need an adjustment calculation. If you've been using a hydrometer, so gravity really is too high, try using an acid-shock starter to acclimatise yeast to the acidic environment before they need to start doing their job. The process is well described here Milk the Funk
It's normally used for bottling long-aged sours, but is worth a shot for your stuck ferment. Note that you shouldn't use wine yeast and apple juice (as described in the process) because it won't ferment maltose. Use a beer yeast and malt extract. I've used US05 down to 3.3pH without problem before, so I think it can get the job done here.
 
I thought about the starter as well but again, if 5 packs of yeast didn't do anything, not sure a starter would help.

The problem with adding dry yeast directly to a sour beer is that the cells are trying to rehydrate in a hostile environment. When they rehydrate, they basically suck in whatever's in the solution around them - in this case, lots of acid and alcohol which means they're likely to be kaput. Even rehydrating in water would be a huge help over pitching dry.
 
Here are a couple of thoughts, 1- pitch a diastaticus yeast starter at high K with the fruit, 2- Kveik strains yield a much lower pH in the finished beer,maybe they can take the acidity at high K( always at high K ). I like the idea of brett on a sour (have a 25 gal lambic barrel) but you could be waiting a year or so. My .02
 
Firstly, how are you measuring gravity - refractometer or hydrometer? Refractometers don't work after fermentation has started because the alcohol skews the reading, so they need an adjustment calculation. If you've been using a hydrometer, so gravity really is too high, try using an acid-shock starter to acclimatise yeast to the acidic environment before they need to start doing their job. The process is well described here Milk the Funk
It's normally used for bottling long-aged sours, but is worth a shot for your stuck ferment. Note that you shouldn't use wine yeast and apple juice (as described in the process) because it won't ferment maltose. Use a beer yeast and malt extract. I've used US05 down to 3.3pH without problem before, so I think it can get the job done here.

Yep, US 05 is my usual go to for kettle sours. It has gotten the job done for me every time. This is my first batch where I pitched the lacto and the yeast in the fermenter. PRIOR to this batch, I've ALWAYS kettle soured to 3.2 pH and pitched US05 dry, no rehydration. I always just overpitch by 1 packet and it's done phenomenal for me. Never failed to start, never stalled. So, that's why I decided to pitch it dry into this one.

I have never done an acid shock starter but I will definitely look into that. That will be handy for future batches.

On a positive note, I added the fruit to this batch and it MAY be fermenting again. I have not taken a measurement but the tilt hydrometer is showing activity, which I know is not necessarily a true sign it's fermenting. And the bubbling has sped up this morning compared to last night after I added the fruit. So we'll see.
 

Yeah, this thread was talking about the same batch. However, wasn't getting much feedback so I started a different thread with a slightly different topic. I took half of your advice from that one and pitched the US05 yeast. While part of the reason that I didn't rehydrate was that US 05 has always worked for me in an acidic environment, there was a second reason also. Rehydrating 4 or 5 packets of yeast is a lot of water and I did not have the room in the fermenter to add that much. So that was the other part of the reason I did not rehydrate.
 

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