Did my fermentation finish?

Discussion in 'Beginners Brewing Forum' started by Tal Orbach, Sep 16, 2018.

  1. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    #1 Tal Orbach, Sep 16, 2018
    Last edited: Sep 17, 2018
    I had been fermenting a batch of beer in a fermentation fridge for the past 11 days. After pitching the yeast I took a bit out, to ferment alongside it, in the fridge, to do my measurements on, to lower the risk of contamination from opening the fermenter every so often. (since I took the sample after the yeast was mixed in, and as it was in the same place, I assume the sample fermented more or less the same as the main batch)
    For the past 3 days, refractometer readings of the sample haven't changed, so I concluded that the fermentation finished and bottled this evening.
    I added sugar for 2.25 volumes of CO2.

    I now took a hydrometer reading from the main batch (without the priming sugar), and it seems a bit too high for it to actually be the final gravity - 1.023. OG was roughly 1.060 (I had some measurement problems, but it was more or less that).
    Does it sound reasonable that this is my FG? (using refractometer calculators that take alcohol into account, the current SG is supposed to be 1.016, but I can't say that I trust the accuracy of the measurement. The only thing I trusted it for is consistency of the measurement, to determine that fermentation is over).

    Should I be afraid of bottle bombs?

    [EDIT]
    Grain Bill:
    5 lbs Maris Otter
    1 lbs Munich 10L
    1 lbs Oats
    1 lbs Biscuit
    1 lbs Pale Chocolate
    1/3 lbs Crystal 60
    2/3 lbs Midnight Wheat

    Mash: 154F (68C) - 1 hour

    Yeast: Nottingham (harvested from previous batch, started quite vigorous , and remain vigorous for a good few days)
    Fermentation - Started at 18C, after a four or five days, bumped up to 19C, a day later - 20C, then - 21, 22, 25 for one last day (Brix hadn't changed since it was at 20C)
     
  2. Hawkbox

    Hawkbox Well-Known Member

    Joined:
    Jul 27, 2017
    Messages:
    3,730
    Likes Received:
    2,967
    Trophy Points:
    113
    Gender:
    Male
    Occupation:
    IT Manager
    Location:
    Edmonton
    I've had a few finishing in the 1.020 range lately for some reason. As long as it doesn't change for 3 days you should be fine... Maybe put them in a tote with a lid on if it helps you sleep better.
     
    Tal Orbach likes this.
  3. J A

    J A Well-Known Member

    Joined:
    Jan 19, 2016
    Messages:
    3,474
    Likes Received:
    2,689
    Trophy Points:
    113
    Location:
    Austin, Texas
    In a hypothetical situation with any generic beer, probably. With this exact beer that you're dealing with, maybe not.
    Without knowing what yeast you used or what your grain bill is or what your mash temps were or what your fermentation temp was, there's no way to speculate about what may or may not have happened to the fermentation. A lot of different factors can cause a hard stall. Sometimes you need to try to restart it to be safe.
    Maybe link the recipe and describe the mash, etc...More info will yield more meaningful feedback. ;)
     
    Mark D Pirate likes this.
  4. Mark D Pirate

    Mark D Pirate Well-Known Member

    Joined:
    Aug 21, 2016
    Messages:
    1,887
    Likes Received:
    1,280
    Trophy Points:
    113
    Occupation:
    Master carpenter , all round good guy
    Location:
    Radelaide SA , Australia
    I wouldn't be using a refractometer for FG unless you have an accurate OG reading .
    I have a fine scale hydrometer(0.990-1.020) for this reason only , I accept losing the 80 mls I need for sample since I taste it anyway.
    As for whether it had actually finished at 1.023 that depends on recipe, mash temp and yeast strain
    A little more information would be helpful.
    Not a bad idea to do a forced ferment test but I allow them to run at higher temp to ensure full attenuation
     
  5. Mark D Pirate

    Mark D Pirate Well-Known Member

    Joined:
    Aug 21, 2016
    Messages:
    1,887
    Likes Received:
    1,280
    Trophy Points:
    113
    Occupation:
    Master carpenter , all round good guy
    Location:
    Radelaide SA , Australia
    Rye barleywine finished at 1.022 and I happily bottled it. (OG 1.108 )
    If an APA doesn't drop below 1.012 I'd be double checking or waiting a little longer
     
    J A likes this.
  6. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    Grain Bill:
    5 lbs Maris Otter
    1 lbs Munich 10L
    1 lbs Oats
    1 lbs Biscuit
    1 lbs Pale Chocolate
    1/3 lbs Crystal 60
    2/3 lbs Midnight Wheat

    Mash: 154F (68C) - 1 hour
    Fermentation - Started at 18C, after a four or five days, bumped up to 19C, a day later - 20C, then - 21, 22, 25 for one last day (Brix hadn't changed since it was at 20C)
     
  7. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    I didn't use it for FG. I used it to track changes (to determine when fermentation is done. After it was done, I used a hydrometer to determine FG.
    Added more information.
     
  8. Yooper

    Yooper Administrator
    Staff Member

    Joined:
    Nov 16, 2013
    Messages:
    2,486
    Likes Received:
    1,566
    Trophy Points:
    113
    Gender:
    Female
    Occupation:
    Happily retired
    Location:
    Upper Michigan/Florida
    Mashing at 154 often means a less fermentable wort. If the FG is unchanging, even with an attenuative yeast, it's done.
     
    J A likes this.
  9. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    I know it's supposed to be less fermentable, but I actually use a few recipe calculator (taking grain bill and mash into account), all of which said the FG should be around 1.015. Is it reasonable that those calculators somehow are wrong?
     
  10. Yooper

    Yooper Administrator
    Staff Member

    Joined:
    Nov 16, 2013
    Messages:
    2,486
    Likes Received:
    1,566
    Trophy Points:
    113
    Gender:
    Female
    Occupation:
    Happily retired
    Location:
    Upper Michigan/Florida
    Yes it's reasonable. The calculators all assume the average attenuation of the yeast and the OG of the wort. Mashing at a higher temperature, using less fermentable ingredients, etc, all play a part in the FG and the calculators can't do that well.
     
    Tal Orbach likes this.
  11. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    So ~1.022 sounds reasonable for something that's mashed relatively high, and with a less fermentable grain bill?
     
  12. Yooper

    Yooper Administrator
    Staff Member

    Joined:
    Nov 16, 2013
    Messages:
    2,486
    Likes Received:
    1,566
    Trophy Points:
    113
    Gender:
    Female
    Occupation:
    Happily retired
    Location:
    Upper Michigan/Florida
    Yes, and since the FG hasn't changed and seems to be stable over a fairly long period of time, I'd call it done.
     
  13. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    Sorry for asking pretty much the same question over and over again, but I just want to be extra sure:
    The issue is that what remained stable was not hydrometer reading from the beer in my fermenter, but rather refractometer readings from the same beer (i.e. wort and yeast - taken just after pitching the yeast) that fermented in a separate jar (to lower the risk of contamination).

    I want to make sure that I can trust that if this reading stabilized - it would mean that the main batch also stabilized (it stands to reason that it does, because conditions are the same, and because while the refractometer can't be fully trusted to determine FG, it can say at least if SG is changing or not, but I want to be sure).

    Also, how do I know it's not a stuck fermentation, but actually full fermentation?
     
  14. J A

    J A Well-Known Member

    Joined:
    Jan 19, 2016
    Messages:
    3,474
    Likes Received:
    2,689
    Trophy Points:
    113
    Location:
    Austin, Texas
    Yep, that...You didn't mention what yeast you used, but with that much crystal, the relatively high mash temp, and the fact that you've had the temp plenty warm for further fermentation. it's not likely that anything would change. With with relatively low-attenuating, high-floccing English yeasts like S04, I don't trust a high FG and will always swirl when it starts to drop out in order to prevent a potential stall.
    If you wanted to be doubly sure that there's not a difference somehow in your sample batch and the main ferment, give the fermenter a good swirl to rouse the yeast from the bottom, leave it for a couple more days at 20 or so and check it one more time. I think I'd be tempted to try that just in case.
    In future, trying a slightly lower mash temp and making certain to aerate the wort extremely will help make sure you get better attenuation with English yeasts.
     
    Tal Orbach likes this.
  15. Nosybear

    Nosybear Well-Known Member

    Joined:
    Jul 16, 2012
    Messages:
    9,380
    Likes Received:
    6,609
    Trophy Points:
    113
    Location:
    Aurora, CO, USA
    How's this: If you fermented an ale at reasonable temperatures for 11 days, you can assume it's done. If you had stable readings, regardless of the instrument used, for three days, it's likely done. And if you repitched yeast, changes in performance from predictions made based on fresh yeast can be expected: It might be done. But if you're still concerned, wait a few days. It will be done. And don't believe everything you read on the web: Except for some Belgian strains, stuck fermentations aren't all that common.
     
    J A and Tal Orbach like this.
  16. Tal Orbach

    Tal Orbach Member

    Joined:
    Jun 21, 2018
    Messages:
    151
    Likes Received:
    18
    Trophy Points:
    18
    Thanks, everyone, for you comments. It really helped ease my mind.
    As of now, the beer is bottled, and since I'm not going to be home for a couple of weeks, I have a friend who will beersit it for me. If anything scary happens, he will open all the bottles and let me know. Anyway, I also asked him to try one bottle a week from now, to see if there's any gushing.
    I'll send an update once I have the beer back.

    Cheers!
     
  17. Mark D Pirate

    Mark D Pirate Well-Known Member

    Joined:
    Aug 21, 2016
    Messages:
    1,887
    Likes Received:
    1,280
    Trophy Points:
    113
    Occupation:
    Master carpenter , all round good guy
    Location:
    Radelaide SA , Australia
    Beer will take a few weeks to carbonate in the bottle , I reread your original post and finally noticed you used Nottingham .
    I always get pretty good attenuation with this strain, did a few English mild type beers that started low og and finished pretty high by mashing high and always found it to be a reliable strain to use
     
  18. Brittney81895

    Brittney81895 New Member

    Joined:
    Oct 27, 2018
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    1
    I was wondering, would it be at all helpful to pour in another packet of yeast after just a week? Assuming that the gravity readings are not stable yet. Could there be enough in the beer to start it working just a little longer to lower FG just a little bit more?
     
  19. Hawkbox

    Hawkbox Well-Known Member

    Joined:
    Jul 27, 2017
    Messages:
    3,730
    Likes Received:
    2,967
    Trophy Points:
    113
    Gender:
    Male
    Occupation:
    IT Manager
    Location:
    Edmonton
    If it keeps going the yeast isn't done, adding more won't really hurt anything but it might not do any good.
     
  20. Mark Farrall

    Mark Farrall Well-Known Member

    Joined:
    Oct 19, 2017
    Messages:
    1,301
    Likes Received:
    1,422
    Trophy Points:
    113
    Location:
    Melbourne Australia
    If your fermentation is stuck there's a chance adding more yeast will help, but it probably won't. Did you mash or use extract? What sort of gravity for the beer?

    First step is to try the rousing mentioned in the thread already, but if that didn't work then you can try adding some more yeast. If it's already fairly acidic or alcholic you may want to acclimatise your yeast. Boil some water and then add 50/50 water and beer and add the yeast to that. When that becomes active, add it to main fermenter.

    The reason this often doesn't work is there just isn't enough fermentable sugars left to get any more fermentation. For one reason or another the wort just wasn't very fermetable and you've got as much as you're going to get.

    If it's that and you're still determined to try other options you can use one of the yeast strains that have the diastaticus genes. These ones are able to ferment more complex sugars than standard yeasts. Though most of these will add some flavour to the beer. This page has a very detailed list of yeasts with non-standard behaviour including ones that are supposed to be able to break down the more complex malt sugars - http://www.milkthefunk.com/wiki/Saccharomyces (just search the page for diastaticus).

    But before you do all that stuffing around, if you've already got past 2.5 ABV try the beer and see if tastes sweet to you. It constantly surprises me how many beers with high finishing gravities just aren't that sweet to taste.

    Then ... (yep there are more steps, but really it's more pain than it's worth, carb it up, drink it and if it's awful, dump the batch and work out what went wrong so it doesn't happen for the next batch)
     
    ChicoBrewer likes this.

Share This Page

arrow_white