Bad thermometer how high can ferm temp swing?

Discussion in 'Homebrewing' started by mijclarke, Nov 27, 2021.

  1. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    I brewed my first stout (sweet stout) a couple days ago and just started brewing last summer. I have an OG of 1.076 and am using US-05 dry yeast that i rehydrated. I have 5 gal glass carboy resting in a Tupperware container with cool/cold water. My digital thermometer is old and used for cooking (food network brand) and I don’t think it’s accurate at lower temps. I got a reading of 81 and freaked out and bought ice as my ice packs (3) were melted and needed to go back in freezer (just got several more ice packs from neighbor). The tub with the carboy is resting in my basement bathroom shower stall. I would guess ambient air temp is high 60’s during day and mid 60’s at night. I’m adding a few ice packs during day. Im smelling a slight fruity ester aroma and I’m wondering if that’s from fermenting too warm. Going to look for a better thermometer tomorrow but was curious what the hottest a sweet stout can get when ambient air in room is upper 60’s?

    thanks,

    Mike
     
    #1 mijclarke, Nov 27, 2021
    Last edited: Nov 27, 2021
  2. VikeMan

    VikeMan Poo-Bah (2,003) Jul 12, 2009 Pennsylvania
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    It would depend on a lot of factors, but I've seen a big beer hit 12 degrees F above ambient temperature, but that's not typical. The fact that you had the fermenter sitting in cold water would have mitigated against that kind of difference.
     
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  3. MrOH

    MrOH Poo-Bah (1,923) Jul 5, 2010 Malta
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    What was the temperature of the wort when you placed it in the water bath?
     
  4. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    My thermometer read 70 and it was late so I pitched yeast, added a couple ice packs and went to bed. I’ve had a glass of water sit overnight on counter and my house thermostat is set to 70 and the thermometer in that glass of water says 79. Does my thermometer seem to be working?
     
  5. skivtjerry

    skivtjerry Zealot (595) Mar 10, 2006 Vermont

    It sounds like your thermometer is off on the high side so your beer is probably ok, at least as far as fermentation temperature.
     
  6. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Oh man! New thermometer is reading 55 degrees. I immediately took carboy out of water bath and am wondering if I should repitch? I suppose I should let it warm up and see if air lock activity increases (fairly slow bubbling currently). Rookie mistake I don’t have spare yeast. This yeast was pitched Wednesday night and it’s Saturday morning. Krausen foam appeared before I dumped a bunch of ice in water bath yesterday so I’m hoping they went a little dormant and didn’t die off around 55 degrees for roughly 24 hours. Would this necessitate a gravity reading to check progress?
     
    #6 mijclarke, Nov 27, 2021
    Last edited: Nov 27, 2021
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  7. PortLargo

    PortLargo Zealot (509) Oct 19, 2012 Florida

    How do you know if the new thermometer is any more accurate than the first one? It's easy to calibrate...fill a glass with ice chips and pour in cold water. Give it a few minutes to stabilize and put thermo in middle of the ice slurry, you should read 32 - 33°. To calibrate high side use boiling water.

    Lots of discussion on Forum about maintaining ferm temps, but rarely do I see posts about the easy way to eliminate the guesswork: install a thermowell. For less than 20 bucks you can have a thermowell with an aquarium temp probe that will tell you exactly the temp in the middle of your primary.
     
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  8. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Definitely wondered about the new ones accuracy so thanks for the tip
     
  9. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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  10. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Funny thing is I have that temp tape on the carboy but it wasn’t helpful when I had it submerged. Now it’s reading 60 and airlock activity is increasing
     
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  11. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    Yeah, you aren't supposed to get the Fermometer wet. It may not work for you now going forward.

    "they can get a little wet. they can't be submerged or soaked though or the adhesive degrades and the liquid crystal will seep out."

    https://www.homebrewtalk.com/threads/how-do-ya-read-a-fermometer-strip.50274/

    Cheers!
     
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  12. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Good to know. Thanks. One last question: my airlock smells like fruity esters. I’m still only on day 4 of fermentation but curious if this smell is normal or could be a bad sign that I stressed the yeast?
     
  13. RJLarse

    RJLarse Poo-Bah (1,994) Dec 30, 2005 Washington
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    On a semi-related note:. It's good to have 2 thermometers on hand. I was heating strike water this afternoon and the thermometer read 80. A few minutes later it was still 80 so I turned up the heat. A few minutes later, still 80 and by now I knew the water was hotter than that. So I grabbed my spare thermometer and sure enough we were at 120 and climbing. No idea how or why I had that spare thermometer on hand. It might have been a gift? But the bad one went in the trash and I'm ordering another spare. Best to have 2.
     
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  14. riptorn

    riptorn Zealot (518) Apr 26, 2018 North Carolina
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    Not speaking from personal experience, but I remember reading that US-05 can throw some peach type aromas when fermented at or below the low end of its temperature range.
     
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  15. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    As a general rule it is not unusual for an ale yeast to produce "fruity esters". For the beers I brew using US-05 I typically find this yeast to be very neutral (e.g., not fruity esters) but for a beer with an OG of 1.076 this may indeed be 'normal'?

    My advice is RDWHAAD (Relax, Don't Worry, Have a HomeBrew).

    Please report back what you think of the resulting beer.

    Cheers! :beers:
     
  16. skivtjerry

    skivtjerry Zealot (595) Mar 10, 2006 Vermont

    Yep, I once fermented WY1056 (the "Chico yeast", pretty close to US05) at 50F and got lots of sweet fruit, though I would not necessarily describe it as peach. This character diminished greatly after about 2 weeks of bottle conditioning. I imagine yanking a keg out of the fridge and giving it a week or so at cellar temps would work too.
     
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  17. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Two nights ago I relocated carboy from basement to the coldest area on my main floor which is at 67 degrees. Yesterday, the fruity ester smell coming from air lock has lessened substantially. Wish I could fast forward in time bc I’m ready to try my first homebrewed stout
     
  18. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    I wanted to just quickly take a small sample to taste but failed. I used a clean tube and tied to plug one end with my thumb and carefully lift the other end out and dump into wide glass on the floor. Despite being successful on the trial run with water, the beer leaked out instantly and i just made a mess. I have the proper equipment to grab a sample but I noticed there is minute amount of dried gunk in a hard to clean area so I decided not to use it.
    Anyways, I did try a drop of the beer and plan on grabbing enough for a gravity reading this weekend. It definitely tastes like an easy drinking stout and although a bit simple in flavor it seems close to done.
     
  19. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Just took a gravity reading and a taste.
    Recipe: OG: 1.060 FG: 1.023 ADF 61% Abv 4.9
    My beer: OG: 1.076 FG: 1.028 ADF 62% Abv 6.3

    Today marks the 10th day of fermentation. Taste is good but a little sweet. I can see this being pretty enjoyable carbed and colder. I know I should probably take another reading tomorrow but I might bottle this tonight. No airlock activity for a couple days and I think I under pitched my yeast. I used one 11.5 gram pack of safale US-05 for 4.5 gallons of 1.076 OG wort with minimal aeration.
     
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  20. VikeMan

    VikeMan Poo-Bah (2,003) Jul 12, 2009 Pennsylvania
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    You should take another reading 2-3 days after the reading you suspect to be at FG. It doesn't take a whole lot of extra fermentable sugars to cause overcarbonation, gushing, and worst case, bottle bombs.
     
  21. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    I’ll probably wait at least 24 hours. I don’t have enough bottles and will need to clean at least 36 of them. It is a sweet stout with a lb of unfermentable lactose so that is probably most of the sweetness I’m tasting. My reading was 1.0275 so I’ll definitely look very closely tomorrow to see if it budged a millimeter or so
     
  22. MrOH

    MrOH Poo-Bah (1,923) Jul 5, 2010 Malta
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    What's the rush?
     
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  23. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    It’s fermenting in my 10 yo daughters room (coolest room on main floor) and I figured if it’s finished and there are no off flavors it’s better to seal it up sooner rather than later. Plus I’m eager to try it with carb in a week or two. Need to grab some priming sugar first though…
     
  24. MrOH

    MrOH Poo-Bah (1,923) Jul 5, 2010 Malta
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    My point is you don't know if it's finished yet. Three days without movement is cheap insurance, and if nothing else, will help with yeast cleanup.

    At this point you can move it to a warmer room with no repercussions if space is the issue.

    Also, just use table sugar to prime.
     
  25. PortLargo

    PortLargo Zealot (509) Oct 19, 2012 Florida

    The opposite is the case. The yeast are not done when you reach FG, that's when the conditioning phase starts. Lots of variables here, but basically a high OG brew requires more time. Here's a detailed explanation on conditioning (scroll down for the details):
    https://www.morebeer.com/category/fermenting-equipment.html#Fermentation
     
  26. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Thanks for the advice and article. I learned more than I thought reading it. I’ll plan on going at least 2 weeks in primary and will try and save plenty of bottles 4 weeks after packaging to see if it peaks in smoothness
     
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  27. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    Yes, beers will further condition within the bottle.

    When I brew my annual batch of Saison I let those beers sit in the bottle several months before drinking them. And for my Quads I do not really start drinking them until at least 6 months in the bottle with the goal to drink the last few bottles at the 5 year mark.

    Cheers!
     
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  28. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Bottled today. Made a rookie siphon mistake - tube on racking cane wasn’t tight enough. Once I got the siphon fixed I proceeded to break a bottle and discovered that the Dos Equis bottles I was reusing may not seal as well bc the bottom lip is very close to the top lip. Only had 6 of them and decided to only use one. Then I realized that a 750ml bottle that contained a wild ale from a local brewery had a fatter lip that my caps couldn’t fit around. I actually paused my bottling raced to Binnys and got some more bottles. Glad I wasn’t bottling an ipa. Plan on trying a bottle with the least amount of headspace in roughly 8 days to gauge the carbonation level.
     
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  29. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    Hopefully your next bottling session will go more smoothly.

    Cheers!
     
  30. riptorn

    riptorn Zealot (518) Apr 26, 2018 North Carolina
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    FWIW....Toward the end of my bottling sessions I often have one or two bottles that are suspect due to excessive headspace, sediment, interruptions, etc. Those 'suspicious' bottles are typically opened first for taste/carb test; and sometimes for no other reason than remove them from rotation. The more properly packaged bottles are reserved for additional conditioning and tasting/serving later.
     
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  31. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Would you say that a 6.3% milk stout would carbonate in bottle as quickly as an ipa assuming temp and priming sugar amount is the same?

    I dissolved about 2.9 oz of corn sugar in a cup of water and poured in 90% of it into bottling bucket once I saw I had 4 gallons instead of 4.25 gallons. I also removed cap from Dos Equis bottle which wasn’t crimped as well and came off super easy and gently poured into another bottle that crimped much better. Probably should move these bottles out of my bedroom but at least I know that Dos Equis bottle will no longer explode
     
  32. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    FWIW I have noticed that my higher gravity beers (e.g., Strong Belgian Ales) require a bit more time in the bottle to reach final carbonation levels, but these beers are > 6.3% ABV.

    With that out of the way I would guess that a 6.3% beer would carbonate at similar rates regardless of style (Milk Stout vs. IPA). But the bottle conditioning process is an actual secondary fermentation so there can be more occurring here than just the aspect of carbonation. You may want to conditions beyond the two week target for carbonation for flavor maturation reasons.

    A strategy you may want to utilize here is try the first bottle at the two week mark to check it out (e.g., fully carbonated? tastes like expected/desired? etc.). You can then perhaps try the second bottle at the three week mark and so on. Once the beer is reaching its peak of flavor - party time!

    Cheers!
     
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  33. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    Update: yesterday I put two bottles with the least headspace in fridge. Opened one with friends last night and carbonation was low - maybe half what it should have. Wasn’t sure if the second one that was in fridge all day would be worth storing at room temp again so cracked that open when another friend arrived. It was only the 10th day in the bottle so I’m going to wait two more weeks before I check again. Unlike my previous ipa batch where I over pitched slightly and there was a lot of yeast at bottom of bottle, the stout bottle has virtually no yeast at bottom - super thin layer. Would going longer than 3 weeks in bottle stop yielding further carbonation?
     
  34. PortLargo

    PortLargo Zealot (509) Oct 19, 2012 Florida

    Lots of variables going on here and difficult to pin down an answer. In my house room temp is 'bout 79, so bottle carb'ing is near complete in less than a week. While 6.3% isn't anything especially high you have doubt on how many active yeasties are still in the game. Another variable to consider is it isn't uncommon for carb level to vary between bottles (result of poor mixing of sugar) . . . shouldn't happen, but sometimes it does. Your plan to wait 2 more weeks is sound . . . evaluate again at that point.

    A po-man's test on measuring carb level before opening is to slowly invert a bottle and hold it up to the light. The sediment (trub) from the secondary fermentation (bottle carb'ing) will slowly drift down and be visible . . . it actually looks kinda gross. Over time you'll be able to estimate carb level based on amount of sediment. Major Caveat: This step will speed up oxidation as any oxygen remaining in the headspace will be mixed with the beer. So only do this for one beer at a time, ideally just before you pop it.
     
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  35. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    As I understand it carbonation will stop once the yeast has consumed all of the priming sugar. As mentioned above the rule of thumb for achieving carbonation is two weeks at room temperature. It will not 'hurt' to let the beers condition for more time (i.e., > 2 weeks) and can be beneficial as regards flavor maturation.

    Please 'remind' me about your process here:
    • What sugar did you use (e.g., corn sugar?)?
    • How much sugar did you use (weight in ounces)?
    • Did you boil the sugar in some water (e.g., a cup of water) and did you very gently stir to ensure proper mixing?
    • What was the volume of beer?
    • etc.
    Cheers!
     
  36. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    I measured 2.85 oz of corn sugar (roughly 2/3 cup) and dissolved in a cup of boiling water. After cooled down, I added most of the priming sugar (about 90%) bc I had 4 gallons instead of the 4.25 gallons I used in the priming sugar calculator. I gently stirred for about 30 seconds. Went from primary fermentation to bottling bucket, no secondary fermentation. Bottles were stored at about 69 degrees. Temp may swing from 67-72 between midnight and noon. One thing that worries me is that I accidentally cooled down wort on day 3 of fermentation to 55 degrees and although I eventually hit final gravity I wonder if that made the yeast not as viable for consuming priming sugars. It was in primary fermentation for two weeks before I bottled
     
  37. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    I consulted an online priming sugar calculator and using 2.85 ounces of corn sugar for 4 gallons of beer at 68 degrees (end of fermentation temperature) the 'result' is about 2.1 volumes of CO2. This is lower than I typically choose as a target level (e.g., 2.5 volumes of CO2). Assuming this calculation is correct these beers will result in a low(er) carbonation value.

    I personally would not be too concerned about the aspect of 55 degrees at day three since you have achieved your target FG (which indicates the yeast was able to complete the job). The yeast should be sufficient to complete the bottle conditioning process.

    Being in the primary for two weeks is OK. Some homebrewers even keep their beers in the primary for longer than that with the concept of further/continuing conditioning.

    Also the aspect of 67 - 72 is a non-issue here.

    My suggestion is to give your bottles another week of conditioning and assuming the above calculation is correct just expect that at around 2.1 volumes of CO2 these beers will not be very carbonated.

    On a related matter I homebrew a batch of English Bitter Ale every year and for that batch I use less than normal amounts of priming sugar to obtain a lesser carbonated beer (to mimic a cask beer). I am personally happy with a lower level of carbonation for that style of beer; it accentuates the the maltiness aspect and mouthfeel for this style of beer. Maybe you will enjoy this aspect in your batch of Sweet Stout?

    Cheers!
     
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  38. mijclarke

    mijclarke Initiate (63) May 4, 2014 Illinois

    2nd tasting update. 9 days after 1st tasting and 19 total days in bottle it was still significantly under carbonated. Fortunately drinking straight from the bottle helps retain the carbonation and the flavor is very good. Eager to try a similar recipe and make improvements. Oxygenate wort better, check fermentation temp with accurate thermometer, use a yeast starter possibly, etc
     
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  39. MrOH

    MrOH Poo-Bah (1,923) Jul 5, 2010 Malta
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    Better yet, brew the same recipe with the improvements so that you can see what they actually do.
     
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  40. JackHorzempa

    JackHorzempa Poo-Bah (5,431) Dec 15, 2005 Pennsylvania
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    Entirely up to you here but I prefer to pour/decant my bottle conditioned beers into a glass so I leave the sediment behind - about 1/4 inch of beer/sediment left in the bottle.

    Drinking the sediment (mostly yeast but other stuff too) will have a flavor impact and consuming live yeast may cause GI distress (e.g., bloating, diarrhea, etc.).
    I would add "properly use a priming calculator" to your list.

    Cheers!