Question on fermentation temperature

Discussion in 'Homebrewing' started by VladamirDiablo, Mar 27, 2017.

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  1. VladamirDiablo

    VladamirDiablo Initiate (0) Mar 27, 2017 California

    Hello I am new to brewing and had a question regarding temperature in the fermentation process. This question arose after my first brew; my beer tastes "hot" and a bit "cidery" which leaves me to believe the temperature was too high or there was too much sugar ( brew kit came with a booster).

    I brewed my beer in a closet that was about 68 degrees consistently. I have been reading that during the fermentation process, the wort can increase in temp 10 degrees higher than the ambient temp. Does this mean that my beer should have been fermented in a room that was 58 degrees to account for the increase (given the optimal fermenting temp is 68 degrees)?

    The aspect of this temperature change has confused me and any help on the subject would be appreciated. Just so you know my brew came from a Mr. Beer kit which was the Long Play IPA. Thank you:slight_smile:
     
  2. csurowiec

    csurowiec Initiate (0) Mar 7, 2010 Maryland

    Your description is typical for a beer fermented warmer than ideal. Yeast chewing through wort is an exothermic process and your fermenter will be warmer than the ambient room temp though probably not 10 degrees warmer. Your best easy solution would be to make a swamp cooler for evaporative cooling. Google homebrew swamp cooler to get an idea of the concept. You can keep it cool with frozen water bottles swapping them out as they melt. 5-6 days in this temp control becomes less necessary and it can even help to let it come up to room temp to let the yeast clean up after themselves before they flocc and fall to the bottom.
     
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  3. Tebuken

    Tebuken Initiate (0) Jun 6, 2009 Argentina

    Assuming your beer kit is an ALE beer your fermentation temperature is fine.We need to know what :

    Yeast used
    OG
    Beer Style
    Why there was a ´booster´ in your kit and what kind of.

    Your concern of fermentation temp. is nothing to worry about (Ale beer) , maybe this cidery taste comes from acetaldehyde(green apples) your beer is still too young.
    You will need to age longer this beer in order to let acetaldehyde convert to ethanol and fusel alcohols(hot taste) converts to esters.

    Please give a try here to start things up :

    http://www.howtobrew.com/

    This way you will be able to understand the whole process of brewing and the terminology I used above.

    Good luck, wellcome abord !!
     
  4. SFACRKnight

    SFACRKnight Grand Pooh-Bah (3,348) Jan 20, 2012 Colorado
    Pooh-Bah Trader

    Sounds like a warm fermentation to me. Esters and fusel alcohols increase as fermentation temps increase. I have an old chest freezer with a temp controller, but prior to that I started fermentation in my basement and would bring the beers upstairs on day 3 to bring temps up a bit.
     
  5. Jaguar10301

    Jaguar10301 Crusader (423) Mar 1, 2010 Maine

    I don't know if you can say it's "nothing" to worry about. I have always gone by the rule of thumb of 10 degrees higher than ambient temp. So at the height of fermentation he might have hit 78 degrees. It all depends on the yeast strain and what the recommended temp is. Even if its not outside of the range a higher temp in the range will produce different flavors.
     
  6. PortLargo

    PortLargo Pooh-Bah (1,831) Oct 19, 2012 Florida
    Pooh-Bah

    The increase in temperature of your wort follows the yeast activity as shown by this chart:
    [​IMG]

    There are about a dozen variables that can shift the yeast activity to left/right/up/down . . . you control some and sometimes the yeast are in charge. The most accurate way to measure is to use a thermowell, not really practical for a Mr Beer. If you can measure the temp of the outside of the container (usually covered in something like bubble wrap) you can approximate wort temp. Lacking a ferm fridge, an ice bath does a respectable job. Your critical time is the first 72 hours after fermentation begins.

    That said, once the yeast start to wind down you typically want to raise the temp (conditioning phase). Fermentation gives undesirable by-products . . . you have described "hot" alcohol and acetaldehyde, which are classic examples of not allowing the yeast to finish. Given time/temp, the yeasties will metabolize those nasties, that's why brewers don't want to rush fermentation. Here's what's going on in your primary:
    https://www.morebeer.com/articles/conditioning
     
  7. JackHorzempa

    JackHorzempa Grand Pooh-Bah (3,375) Dec 15, 2005 Pennsylvania
    Society Pooh-Bah

    As others have mentioned it sounds like this batch was fermented too warm and for future batches you should take some steps to manage the temperatures like placing the fermentor in a water bath cooled with ice jugs or evaporative cooling.

    “…my beer tastes "hot" …” That is an indicator of higher alcohols (fusel oils) which commonly are formed during warm/hot fermentations.

    “…a bit "cidery"…” That could be due to the formation of acetaldehyde.

    Further conditioning of this batch could help improve these matters.

    For future batches, take steps to manage your fermentation temperatures.

    Cheers!
     
  8. Jaguar10301

    Jaguar10301 Crusader (423) Mar 1, 2010 Maine

    Yeah for the record I had one beer that fermented way too hot. It was a 90 min IPA clone, that was a crazy mess and hectic brewday. Anyways it was a vigorous fermentation (only time i've ever blown the top) and it was the summer, and I didn't use a starter.

    Needless to say it was HOT. Fusels my lord! After a month or so of aging it was one of my favorite beers I'd made. So yeah, if its too hot, let her sit..
     
  9. VladamirDiablo

    VladamirDiablo Initiate (0) Mar 27, 2017 California

    Thank you all for your help on this! Just so you know, my beer was in the fermentation chamber for 3 weeks then sat in bottles for another 3 weeks until I tired the first one. From what you are all saying, it sounds like the first few days are when the yeast creates additional heat and this is when I should watch the temperature carefully to not overheat. So the important factor is wort temp when brewing and not ambient temp?

    I plan on getting rid of the Mr. Beer kit and moving up to a brewing starter kit for $150. The Mr beer kit was ok, but now I have a case of "brewing fever" so I am excited to make something better and not repeat the same mistake again of not controlling my temperature correctly.

    I am glad the fusel alcohols will dissipate after time which makes me happy that I wont have to dump the whole batch. I drank about 24 ounces of this beer the other day and woke up with the worst headache of my life. :astonished:
     
  10. JackHorzempa

    JackHorzempa Grand Pooh-Bah (3,375) Dec 15, 2005 Pennsylvania
    Society Pooh-Bah

    Yup. Make sure to get a fermometer with your new brewing kit so that you can monitor the temperatures in the fermentor.

    https://www.morebeer.com/products/fermometer-adhesive-thermometer.html

    I would highly recommend that you purchase the book "How to Brew" by John Palmer along with that kit.

    Well that confirms it; you definitely generated a lot of higher alcohols (fusel oils) with your warm/hot ferment. I am not sure how long it will take but hopefully the higher alcohols will diminish somewhat with bottle conditioning time. Maybe it would be prudent to restrict your drinking of this batch to one bottle per session?

    Cheers!
     
  11. VladamirDiablo

    VladamirDiablo Initiate (0) Mar 27, 2017 California

    I will definitely buy the how to brew book. it seems like it is a pretty comprehensive guide on the subject.Thanks for the help on this!
     
  12. VikeMan

    VikeMan Grand Pooh-Bah (3,067) Jul 12, 2009 Pennsylvania
    Pooh-Bah

    Some, maybe even much, of the fusels might be converted to esters by whatever active yeast are left in the bottles. It depends on whether or not the yeast are in a state where they need the fusels and whether or not there are enough yeast cells. But other than conversion by yeast, there's no pathway I know of that removes fusels from beer.

    Hopefully your beer's fusel issue will improve significantly. It sounded like you were under the impression that it will, but only time will tell. I'd suggest you keep the beer at room temp, which should help keep the yeast active. Cold temps slow down most biochemical yeast processes.
     
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  13. wspscott

    wspscott Pooh-Bah (1,958) May 25, 2006 Kentucky
    Pooh-Bah

    I think there is a new version coming out soon, it might make sense to wait a little bit vs. buying the old version. Homebrewing has changed a bit in the last 10 years.
     
  14. crcostel

    crcostel Initiate (0) Feb 26, 2006 Illinois

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