Stuck fermentation with a high abv beer

Discussion in 'General Brewing Discussions' started by Djjolt, Dec 8, 2018.

  1. Djjolt

    Djjolt New Member

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    I have a stuck fermentation, what do I do? Here’s the details and tricks I’ve tried.
    Brewing a strong scotch ale, this is a 1 gallon batch, target final gravity 1.035.
    OG-1.148, fermentation started about 24 hours at ~60-68 degrees, it fermented normally for a couple days then stopped around ~1.077-1.070, and I kept the temp in the 60-68 range.
    I also use a “tilt” digital hydrometer, it’s floats inside the fermentor, so I can get instant readings of temp and gravity without disturbing fermentation or having to take a sample.
    So after monitoring for a few days an slowing raising the temp to ~70-72 and swirling the fermentor to rouse the yeast, the gravity has stayed at ~1.074-1.070.
    After 3 days with the same gravity range nowhere near the target gravity, I mixed a cup of water with 2 tablespoons of brown sugar and 1/4 teaspoon of yeast nutrient at 75 degrees then added about 1/3 packet of dry yeast, waited to make sure the yeast was active and then added that mix to the fermentor, and 48 hours later keeping the temp ~70-72, the gravity is still ~1.072.
    So is this beer a dumper, or is there another trick I can try? I don’t want to spend any extra money on things like liquid yeast.
     
  2. thunderwagn

    thunderwagn Well-Known Member

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    Did you happen to use a yeast calculator? That's a huge beer, and you need enough strong, healthy yeast to handle it.
     
  3. Head First

    Head First Well-Known Member

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    What yeast are we talking about?
     
  4. Djjolt

    Djjolt New Member

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    I used about 2/3 a packet of safale 04, for the original yeast pitch, and about 1/3 of a packet for the stuck assist, as this is only a 1 gallon brew.
     
  5. thunderwagn

    thunderwagn Well-Known Member

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  6. Hogarthe

    Hogarthe Well-Known Member

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    That's already at 12% abv. It might be more than s04 can handle, if you can get a high gravity yeast to finish it you might have better luck. One trick for really big beers is to aerate the wort at pitching and add more the next day. The yeast need lots of oxygen for such a big gravity, and they will use it all up, even the second addition so no need to worry about stale flavor.
     
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  7. Djjolt

    Djjolt New Member

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    So I should be safe to add another packet of yeast. Do I need to hydrate it because of the amount of alcohol already in the beer or can I just sprinkle it in and stir like mad and reseal it.
     
  8. Hawkbox

    Hawkbox Well-Known Member

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    Fermentis says just sprinkle it on top, so I wouldn't worry to much.
     
  9. Djjolt

    Djjolt New Member

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    22D1E080-3F4C-44A5-9244-8CC6633DE626.png Thanks for all the info. I pitched a whole packet of yeast and stirred it like crazy and it already dropped to 1.060.
    I’ll attach a screen shot of the graph that the “tilt” produces so you can see what I’m seeing.
     
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  10. Nosybear

    Nosybear Well-Known Member

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    You started at 1.148? Answer's simple: Alcohol killed your yeast. Using the alternate formula in the ABV calculator, more accurate in your situation, you're at 12.15% alcohol. That's using the 1.074 ABV I see as the more likely FG value from your chart. I'm guessing that rapid dip was some kind of measurement error in the digital hydrometer you're using. If you want to get this any lower, you'll need some highly alcohol tolerant yeast - a champagne yeast (EC 1118) might drop your gravity some more. And one more question: Why did you think you needed to start a beer with a wort higher in sugar than most wine musts? If you were to get to 1.035, you'd have 18% alcohol, the upper limit of champagne yeast's tolerance. Under perfect conditions. In other words, your problem is simple: Your beer is too damned big.
     
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  11. Mark Farrall

    Mark Farrall Well-Known Member

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    Before you spend too much time stuffing about with getting it going again grab a sample and see what it tastes like. It's amazing how often you'll see a high FG and think it'll end up tasting like treacle, but when you try it it's completely drinkable (assuming you're the type of person who drinks imperials and based on your recipe I expect you are).

    Even if you decide that it's a dumper it's still worth bottling half a dozen or so, giving them three months and then see how the beer changes by opening one each month or so. You may end up pouring 90% down the sink but it's still some return for your effort.

    Edit: Oops, you've already pitched more. Well take this as a comment in case you disappear down the rabbit warren of champagne or sake yeasts.
     
  12. Nosybear

    Nosybear Well-Known Member

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    I agree with Mark. I don't think this is going to go any lower so taste it. If it's in your "good" range, package it and drink it. If it's too thick, cut it with water. It might even start fermentation again if you get it below an ABV toxic to yeast.
     
  13. Djjolt

    Djjolt New Member

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    The yeast I added dropped it about 10 points down to 1.059, and I think that batch of yeast died. I did taste it when I was adding the yeast, it was actually really good, nice toasted caramel flavors, so I’m just going to let sit a few more days until I have time to bottle it (maybe it will drop a couple more points). Should I be concerned about putting a beer with a gravity that high in bottles?
     
  14. Mase

    Mase Well-Known Member

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    Gotta look for a consistent gravity reading over at least 3 days at fermenting temps, that will let you know if fermentation is complete.
     
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  15. Nosybear

    Nosybear Well-Known Member

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    Gravity that high isn't the issue: Do you have sugars in it? If so, you could be making bottle bombs by bottling it. There's a test - used to be used for testing urine samples for sugar (diabetes) but works well for beer/wine if you can find it. I believe they're called Clinitabs, you add the tab to a sample of liquid, it goes through its reaction and the color tells you how much sugar is left. But they're expensive and hard to find. If you've dropped it to 1.059 you're in the 14% alcohol range, that should be enough to keep anything that can digest the residual sugars and dextrines from doing anything. Kind of a meandering path but if your measurements are accurate, you shouldn't have any problems bottling it. Carbonating it may be a different story.
     
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  16. Mark Farrall

    Mark Farrall Well-Known Member

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    Yep, guessing you've laid waste to whatever yeast you've got left. If there's any simple sugars left they're too buggered to ferment it. But at this stage better to play it safe and not add any bottling yeast, just the bit of sugar. May take many weeks to get any carbonation, but beers that big can carry off a lower carbonation than most.
     
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  17. Djjolt

    Djjolt New Member

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    Thanks everybody for all of the info, I bottled it after it sat at 1.059 for a few days, I didn’t add any priming sugar and tasted it at bottle time, it’s very thick silky and sweet in a good way lots of caramel, and molasses notes, it should be tasty, in about a month or two or five, if it doesn’t carb that’s ok.
    But thanks again for the help, I learned a lot from this brew, it somewhere around my 30th home brew, and I did work in brewery for a while years ago, so it goes to show I’m still learning and growing.
     
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  18. Head First

    Head First Well-Known Member

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    If you are happy with the end result that is what matters, right? You probably already have a plan for this but I would give it 2 to 4 weeks and check one out. If for some reason it decides to finish lower and is over carbing, if you have room you can put it in the frig and still enjoy it without it blowing.
     

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