Temp swings during fermentation

Discussion in 'General Brewing Discussions' started by mrskittle, Jun 2, 2020.

  1. mrskittle

    mrskittle New Member

    Joined:
    Jan 5, 2020
    Messages:
    22
    Likes Received:
    18
    Trophy Points:
    3
    Hey folks. I've got half a dozen brews under my belt so I know just enough to be dangerous. One issued that I've struggled with a bit since starting this January is finding a place to stash the fermentor where the temp is most consistent. While it was still winter, I kept my fermenting batches in the bedroom closet. Some days the closet smelled Glorious!!! That worked fine until outside temps start getting above 60 or so. On sunny afternoons, that room can get pretty warm. I'm really suspicious that a warm day, on day 3 or 4 of fermentation, led to some fusel alcohol formation and a slight boozy character of my last batch.

    So as temps have been warming up, I moved to fermenting on the main level of the house. It had been an even 65 degrees for days. It would have been just right for an ale yeast. But (un)fortunately, the outside temp keeps going up and we had a day the house got up to about 70. I mean after winter and the cold spring we've had, 70 in the house without the furnace felt great but it got too hot for the yeast considering the interior or that 5.5 gallons of wort can be anywhere from 5-10 degrees warmer than ambient. Again, this was right in the critical first 5 days of fermentation. I was able to put the fermentor in the basement after being exposed to the higher temps for only a few hours. The basement is about 62 degrees or so.

    So here my big question: Before this short exposure to slightly high temps, high Krusen has passed and the foam layer had mostly cleared up. A second layer of foam had come up as a result of the temp rise ( i believe) and has still not cleared up about 5 days later. Otherwise fermentation is proceeding fine. I'll be dry hopping in a day or two.

    I can post a pic of the current foam if anyone thinks that will be helpful.
     
  2. Nola_Brew

    Nola_Brew Active Member

    Joined:
    Jul 9, 2015
    Messages:
    328
    Likes Received:
    186
    Trophy Points:
    43
    Location:
    Looziana
    If you were within the temp range for the yeast you used during the first 5 days or so of fermentation you should be fine.
    Most people raise temps to 70 or so towards the end of fermentation to help the yeast finish and clean up.
    If you didn't get above 80 you should be ok.
    A swamp cooler may be what you need to keep fermentation temps in check. Or you could use Kveik yeast which will allow you to ferment at higher temps.
     
  3. BOB357

    BOB357 Well-Known Member

    Joined:
    Feb 3, 2018
    Messages:
    3,275
    Likes Received:
    5,516
    Trophy Points:
    113
    Location:
    Fallon, Nevada
    I'd guess that the yeast had begun to flocculate and was roused when you moved the fermenter. Give it some time at the cooler temperature and it'll resettle. There's really no problem adding the dry hops now. The CO2 produced by the tail end of fermentation will help scrub out any oxygen you introduce when adding the hops.
    Absent any active temperature control, it sounds like your basement is the place to ferment. The low 60s are reasonable for many styles. Ideally, I'd be shopping for a dedicated fermentation fridge. That and an external temperature controller will give you the control you need to greatly improve you beers.
     
    ^Tony^ likes this.
  4. Nosybear

    Nosybear Well-Known Member

    Joined:
    Jul 16, 2012
    Messages:
    8,623
    Likes Received:
    5,545
    Trophy Points:
    113
    Location:
    Aurora, CO, USA
    I've found that fluctuations are more damaging to the beer than a consistently high temperature. Just my observation, no science behind it. Once I had a means to control the temperature and keep it more or less constant, my beers improved immensely.
     
  5. ^Tony^

    ^Tony^ Active Member

    Joined:
    Jul 25, 2018
    Messages:
    158
    Likes Received:
    132
    Trophy Points:
    43
    Gender:
    Male
    Location:
    Western Canada
    Your batch is probably just fine. Moving it might have roused the yeast enough for a little secondary ferment. I'd say that is a good thing. I would just give it a few extra days to finish up the ferment then drop clear.

    If you are hard up for a temp control method (can't do a swamp cooler, etc) I have a very basic suggestion. I used to put my fermenter into a wooden cabinet with 1/2 think solid wood sides that was just big enough to fit the fermenter with blow off tube on it. The cabinet was not air tight but it sealed pretty well. I set up a thermostat so I could note the temp without opening the cabinet. There was variance throughout the day but less than half that of the ambient room temperature change. Not a great set up but better than nothing.
     
  6. mrskittle

    mrskittle New Member

    Joined:
    Jan 5, 2020
    Messages:
    22
    Likes Received:
    18
    Trophy Points:
    3
    #6 mrskittle, Jun 3, 2020
    Last edited: Jun 3, 2020
    I'm not terribly worried that the batch won't turn out fine, but I'm still new enough at this that I'm just fishing for some insight and information about something in the process that I haven't seen before. I'd like to think that it was just the moving of the carboy that roused the yeast a bit, but the foam had already formed over a few hours before I moved it.

    Yesterday I went ahead with 3 oz of dry-hop pellets and it didn't seem to do anything to diminish the foam/froth. Now the majority of the hop material is sitting on the surface of it. They seem to be rehydrated but are not sinking. Any idea is this is going to make my dry-hop ineffective?
     

    Attached Files:

  7. Frankenbrewer

    Frankenbrewer Active Member

    Joined:
    Jul 19, 2019
    Messages:
    242
    Likes Received:
    237
    Trophy Points:
    43
    Just set it and forget it. The hop material will eventually start to fall to the bottom along with the krausen. I have been brewing almost 2 years and the one thing I'm still trying to master is "PATIENCE"
     
    Herm_brews, Mark Farrall and ^Tony^ like this.
  8. ^Tony^

    ^Tony^ Active Member

    Joined:
    Jul 25, 2018
    Messages:
    158
    Likes Received:
    132
    Trophy Points:
    43
    Gender:
    Male
    Location:
    Western Canada
    Yup. The first brew I every did felt like it took forever to finish.... The first dry hop I did I had the same thought. I didn't want to waste the time and effort on my bad technique. The hops floated for a few days then dropped out like the yeast does. I even left one high octane BGSA batch in the primary for 5 weeks before I had a chance to bottle it. It was beautifully clear by then and tasted just fine. Now I never worry about how long it takes to ferment until the batch has been in the primary for more than 4 weeks.

    That picture looks like your brew is still in full on fermentation, and a good one at that. You may end up with a really nice bio transformation dry hop like a NEIPA calls for. I would wait at least a week or until everything drops then Id give it a few more days and start testing it to see when the gravity stabilizes.
     
  9. HighVoltageMan!

    HighVoltageMan! Well-Known Member

    Joined:
    Feb 2, 2015
    Messages:
    734
    Likes Received:
    652
    Trophy Points:
    93
    Location:
    Big Lake MN
    The hops are kept a float from escaping co2. The fermentation could be nearly or completely done and this will occur. I'm the sort that would give the carboy a stir a bit of a shake to drop them back down and the next day less would come back up, do it again, etc. By day 3 they mostly have dropped. You don't have to do this, but it's kind of fun. Day 3 of dry hopping I crashed cooled the beer and everything drops like a rock. It's the co2 still in the beer that keeps the floaties up top. Once it's cooled, the co2 goes back into solution and there is nothing to keep them floating.
     
  10. Hawkbox

    Hawkbox Well-Known Member

    Joined:
    Jul 27, 2017
    Messages:
    3,171
    Likes Received:
    2,308
    Trophy Points:
    113
    Location:
    Edmonton
    Yeah they took a week or so to drop out the first time I dry hopped. I had a bit of a panic attack thinking I screwed something up.
     
  11. mrskittle

    mrskittle New Member

    Joined:
    Jan 5, 2020
    Messages:
    22
    Likes Received:
    18
    Trophy Points:
    3
    I know it looks like high krausen but that's just the hops sitting on top. The first high krausen had come and gone a day or so before the "second krausen".

    I know that patience is a virtue but my keg ran dry yesterday and I want this to be ready!! I was hoping to keg this batch in a couple more days, after 13 days in the carboy, but I think I'll let it go until after the weekend. I'm sure moving it into the colder environment will slow down the yeast a bit.

    I have to say that I never had any abnormalities with fermentation when I was using dry yeast, but the last couple times I've used liquid and have a little different result. My latest batch is a 2.5 gallon with yeast from the bottom of Oberon bottles and stepped up 3x with starter. I'm guessing I'll get yet another variation of fermentation. The nuances of yeast and fermentation have so far eluded me in my young brewing journey. I got the feeling on my very first batch, but now I know for sure, stable fermentation conditions are going to be an issue in my 107-year-old house. As a former cabinet maker, I'm sure I can come up with a nice compact chamber for climate controlled fermentation.

    I do have to admit that I did, very gently, swirl the carboy and lots of the hop matter fell. I'm hoping that'll start a chain reaction and the rest of it will clear up nicely. Or I could just have patience...... but I can't help it. I'm one of the many COVID unemployed and I have too much time on my hands. Speaking of, I better go check my carboy again...
     
    Blackmuse and Megary like this.
  12. mrskittle

    mrskittle New Member

    Joined:
    Jan 5, 2020
    Messages:
    22
    Likes Received:
    18
    Trophy Points:
    3
    Update: the head is almost all gone now. There is just a think layer of hop matter still floating. It's got at least 2 more days before I'll consider kegging it so I'm feeling good. I'm also getting the most lovely aroma through the air lock. Although I missed my final gravity by about 8 points and my ABV will lower than I hoped, I still think this is going to be one tasty brew! Thanks for all your ideas and input folks.
     
  13. Hawkbox

    Hawkbox Well-Known Member

    Joined:
    Jul 27, 2017
    Messages:
    3,171
    Likes Received:
    2,308
    Trophy Points:
    113
    Location:
    Edmonton
    My 34/70 Schwarzbier went the opposite direction for temperature I had intended so I have concerns about what I'm going to end up with.
     
  14. Blackmuse

    Blackmuse Well-Known Member

    Joined:
    Jul 8, 2012
    Messages:
    519
    Likes Received:
    449
    Trophy Points:
    63
    Gender:
    Male
    Occupation:
    Electrician (Previously a 6th grade Teacher)
    Location:
    Maine
    What you need to do is brew another batch to eat about about 4-8 hours of your day :) lol

    I don't even have to get an empty keg to get the itch to try and rush a brew - and I've been at it for 10 years now! lol

    CHEERS
     
    Chaos home brewing likes this.
  15. Craigerrr

    Craigerrr Well-Known Member

    Joined:
    Mar 14, 2018
    Messages:
    3,401
    Likes Received:
    4,450
    Trophy Points:
    113
    Trust me, give it another several days, the hops will settle, and in the process will impart their aromatic splendor onto the beer!
    And the congregation said Amen!
     
    Chaos home brewing likes this.
  16. mrskittle

    mrskittle New Member

    Joined:
    Jan 5, 2020
    Messages:
    22
    Likes Received:
    18
    Trophy Points:
    3
    Well the beer turned out GREAT! I put it in the fridge for a cold crash on day 16 and put it in the keg about 18 hours later. I force carbonated it and ended up staying up late drinking becuase I didn't draw the first pint till after 10 and I was so pleased that I had a few...
     

Share This Page

arrow_white