avoiding oxidation

Discussion in 'Beginners Brewing Forum' started by Ward Chillington, Dec 13, 2018.

  1. Ward Chillington

    Ward Chillington Well-Known Member

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    Up until recently, I have been leaving my brew in the carboy for about 10-15 days or until clear after signs of active fermentation have stopped before bottling and now I am thinking about wanting to check SG a few times towards the end to make sure the beer is stable or maybe dry hopping. Both of these activities seem to be a potential point to introduce oxidation of my beer.

    What should I be doing to avoiding exposing the beer to too much air when I do this and getting the dreaded cardboard taste? I'm using a simple rubber stopper and a 2 bulb lock in a glass "water cooler" style carboy. In what steps am I at the most risk of spoiling the batch with too much air and how can I best prevent or lessen the chance of oxidation?

    Am I worrying too much or should I relax and have a homebrew?
     
  2. jmcnamara

    jmcnamara Well-Known Member

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    To my recollection, none of my brews have oxidized. Sure there were some other off flavors, but never cardboard.
    After fermentation there's a nice thick layer of co2 on the beer, which is heavier than air.as long as you don't disturb it too much, that co2 should mostly stay there when you go to sample from the top. If you had a spigot on the carboy, that's even better to pull a sample from the bottom.
    As for dry hopping, if you throw them in during active fermentation there should be enough activity to push out any oxygen you may have introduced
     
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  3. jmcnamara

    jmcnamara Well-Known Member

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    I would also say that during transfer you're more likely to risk introducing oxygen. Keep splashing to a minimum and you'll be good
     
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  4. Ward Chillington

    Ward Chillington Well-Known Member

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    Right....forgot that point along with a whole lot of other details from high school chemistry class! Thanks guy!
     
  5. The Beerery

    The Beerery Active Member

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    It's actually much more complex than that.. Yes co2 is heavier than air, but you have partial pressures, and atmospheric diffusion.

    Also only at the very last stage of oxidation is there sherry and cardboard. There are many steps inbetween. Namely loss of flavor and aroma.

    Also, all beer is oxidized, the minute the yeast go dormant. The real question is how much.
     
  6. Mark Farrall

    Mark Farrall Well-Known Member

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    So basically repeating what rabeb25 posted. You will oxidise. It's going to depend on how long you take to drink your beer and the style whether it will be noticeable (though some will argue that you wouldn't be able to tell as there was a better, less oxidised version of your beer that you never tasted). Apart from dry hop while there's still some activity the answers are all about changing your equipement (spigot in your fermenter to get samples without introducing oxygen, ports and C02 to push from fermenter to keg).

    I've seen a few sensory trials to look at how significant this is at home brew level. It's not a simple answer, the little I've seen is even contradictory. So it definitely happens and can effect some batches, but what batches and what styles is much harder to say. I just try and minimise things in the packaging process and if I'm looking at new equipment think about it then.
     
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  7. Ozarks Mountain Brew

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    pellet hops also have some oxygen inside and any time you keg hop you should pull the release valve periodically
     
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  8. Nosybear

    Nosybear Well-Known Member

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    As mentioned above, oxidation is inevitable: At our scale there are just too many chances for the beer to take up air. You can help by limiting the number of transfers and by not splashing or agitating the beer when you must. If you want to get very fancy, you can invest in a carbon dioxide tank and regulator then flush any vessel you transfer beer to (my method), but there will always be some dissolved oxygen in there.
     
  9. thehaze

    thehaze Active Member

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    To limit oxidation on dry hopped beers, I only take one sample to check gravity, at the same time I dry hop. Two days later I will bottle. I will never take more samples, as I believe opening the beer two times - dry hopping and bottling - will introduce enough O2 to negatively impact the beer. Knowing how an yeast will behave and how many days it takes to ferment a beer, helps synchronising the moment of dry hopping.

    I bottle hoppy beers at day 11, 12 or 13. 5 days later the beer is carbonated ( may not be fully, but plentiful ). They hold up to a month, as I usually give away and / drink them myself.
     

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