Fermentation headspace affect activity?

Discussion in 'General Beer Brewing Discussion' started by Stephenj, Dec 11, 2019.

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  1. Dec 11, 2019 #1

    Stephenj

    Stephenj

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    Hi everyone. I know airlock bubbling doesn't mean everything but just wondering if anyone knows if large primary headspace impacts on activity?

    I've brewed a beer I've done before with same yeast as before but in a small scale, 12l, in a 23l FV. Yeast pitched yesterday. After 24 hours last time I noticed sig activity. This time nothing. Does the space the CO2 have to fill impact on activity? Cheers in advance.
     
  2. Dec 11, 2019 #2

    Cowman

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    I've done a couple 1 gallon brews in the 5 gallon fv and haven't had any problem with attuation but the airlock did very little. Presumably because in the larger space its harder to build up pressure to make the airlock bubble
     
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  3. Dec 11, 2019 #3

    terrym

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    Are you sure your FV lid is sealing? It might look as if it has sealed, but maybe it hasn't, and CO2 is bypassing the airlock. If you want to make sure of a seal place four strips of cling film across the rim of the FV and replace the lid. If the fermentation is underway you will then see a bubbling airlock. Otherwise just leave things alone, rely on the yeast to do its job, and check that the fermentation has finished in about 10 days plus time.
    And to put it into perspective every 180g of fermentable sugar as glucose you have in your wort produces roughly 88g of CO2 (as well as 92g ethanol) and that is equivalent to about 45 litres of CO2 at ambient conditions, which is a significant volume of CO2 and won't take long to start the bubbler going once the fermentation is underway.
     
  4. Dec 12, 2019 #4

    Harbey

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    Just be patient. I've had brews which kicked off within a few hours and then, using the same yeast, had ones which take a few days.
     
  5. Dec 12, 2019 #5

    An Ankoù

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    It's just as likely to be a question of ambient temperature and the pitching temperature of the wort. It's much easier to cool your wort in the winter as the mains water is colder. Once the yeast gets going the fermentation itself will produce heat, and off we go, but I find the colonisation time- visually, the time it takes the same yeast to cover the surface of the beer, is quite sensitive to even a couple of degrees of temperature difference.
    Unlike others who say you shouldn't keep removing the lid (and they're right, by the way) much of the joy of brewing, for me, is observing what is going on. So I like to have a little peek in the early and final stages.
     
  6. Dec 12, 2019 #6

    Stephenj

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    Krausen forming, sitting nicely at 20c. Still no visible activity in airlock but 100% certain lid secure. Sure it's all grand in that there FV, just wondered if and how space might have an impact. Cheers for input everyone.
     
  7. Dec 12, 2019 #7

    Nicks90

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    It doesn't.
     
  8. Dec 13, 2019 #8

    johncrobinson

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    Dont think it makes any difference
     
  9. Dec 13, 2019 #9

    GerritT

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    Nah. Like has been said before: it takes more effort to build up pressure to activate the water lock with a larger headspace. But activity should be the same. If anything, the larger amount of oxygen should be advantageous for fermentation.
     

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