Stuck fermentation idea

Discussion in 'General Brewing Discussions' started by Forrohan, Sep 8, 2020.

  1. Forrohan

    Forrohan New Member

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    I'm an all-grain brewer and finally encountered my first stuck fermentation after 80 batches. My OG is 1.072 and I have made this recipe before and I usually get an FG of 1.021. But my FG has been stuck at 1.042 for three straight days now. I'm not too worried about what caused this at the moment but more wondering if my solution can possibly bring me to my desired 1.021 FG.

    I have a 15 gallon conical fermenter with 12.5 gallons of wort. My thinking is to cold crash with my glycol chiller and drop the yeast and then dump it. Then gradually warm up the wort to around 68 degrees and pitch some new yeast and hopefully that will eat up the 1.042 wort. Sort of like starting from scratch but instead my new OG is now 1.042!

    Sooooo...is my thinking flawed and am I missing something?!?
     
  2. Nosybear

    Nosybear Well-Known Member

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    Before you do a lot of potentially oxidizing your beer, first let's figure out if it really is stuck. First, how are you measuring gravity? It matters if you're using a hydrometer or refractometer once there's alcohol in the beer - the number you cite sounds like an uncorrected refractometer reading. Second, what yeast are you using? Some Belgian yeasts are notorious for looking like they're stalled - they're not. Third, maybe that's really your final gravity. It's awfully high but it still could be. The final possibility is you did something to kill all your yeast, that's hard to do but it could somehow happen.

    No need to go through all the machinations, if you can eliminate measurement problems as the cause, just pitch the new yeast. Stir up a starter and pitch it at high krauesen (the starter's), no need to chill, dump, etc. If your old yeast is truly dead, it won't mind a few new cells eating through the remaining gravity, if there is any.
     
  3. SabreSteve

    SabreSteve Well-Known Member

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    I just got my refractometer yesterday and even though I'm planning on letting my batch sit close to another week (brewed a week ago today) I decided to take a reading to try it out. I came to the same conclusion that my fermentation was stuck because the SG was way too high. This was crazy to me because the fermentation took off so quickly it nearly blew off the airlock. Then I remembered being told I'd need software to correctly use a refractometer. So I plugged the numbers into the calculator here on BF and discovered that it isn't stalled, it's reached it's FG after all. Just something to consider if you've recently switched from a hydrometer to a refractometer.
     
  4. Mark Farrall

    Mark Farrall Well-Known Member

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    I'd try a forced fermentation with a litre or so, to see if there's any point to adding new yeast. Then if that kicks off you can add that at high krausen to revive things.

    Worst case with your approach is it was a mashing mistake and it's just a really unfermentable wort, so adding more yeast will never change the equation. It may need some enzymes to fix up the conversion, either exogenous, or from something like WLP-099.
     
  5. BOB357

    BOB357 Well-Known Member

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    Remember, if you want accurate readings you'll need to caculate the wort correction factor, which is specific to your refractometer.
     
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  6. Craigerrr

    Craigerrr Well-Known Member

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    This SabreSteve kid, the undrafted 29 year old rookie, he is looking right at home, isn't he!
    You are learning a lot there, aren't you Steve, before you know it, you will be answering questions that you don't yet know to ask.
    So, who are you cheering for?
    I'm kind of liking the Islanders, and it takes me back to when they were unbeatable, Bossy, Trottier, Potvin, Billy Smith, Goring, gillies, Morrow, Nystrom, D. Sutter, Tonelli....
     
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  7. SabreSteve

    SabreSteve Well-Known Member

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    I'm 32... :D
    Actually not a fan of the Isles. They just play such a boring brand of hockey. I'm hoping for a Vegas-Tampa final beyond that I really don't have a preference right now. I think Tampa might do it this year though. They look as unstoppable this postseason as they did in the regular season last season.
     
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  8. Craigerrr

    Craigerrr Well-Known Member

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    Sorry for the derail, back to stuck fermentation
     
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