Fermenting in a keg

Discussion in 'General Beer Brewing Equipment Discussion' started by liamf89, Dec 7, 2017.

  1. Dec 7, 2017 #1

    liamf89

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    Hi i have been looking into idea of fermenting in a keg as I normally have couple empty and want to lower chance of introducing oxygen to beer and do closed transfer.. I have been googling a bit and just keep seeing about spunding valve.. Could I not just transfer my wort between two kegs purge the head space then attach disconnect to in valve and on disconnect just attach bit of tube and stick on some star san to allow gas to escape.then when ready to transfer connect disconnects from keg with beer into empty on and the connect gas to one with beer in and set low pressure to get beer flowing to empty keg..
     
  2. Dec 7, 2017 #2

    Bigcol49

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    Hi!
    Won't the problem be over-carbonation? The recommendation is to transfer from the FV to a keg when the beer has 2 to 5 points to go before fermentation is over. The spunding valve is to ensure that the beer is not over-carbonated.
     
  3. Dec 7, 2017 #3

    Sadfield

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    Yes you can. Ferment in a corny. The only issue is leaving enough headspace in the keg for the krausen.

    The advantage of the spunding valve is that you can dial in the pressure required and carbonate as you ferment, and also when fermenting under pressure you can ferment warmer with less ester production. Another benefit is that top pressure suppresses the krausen, meaning less headspace is needed in the keg.

    Edit: I've actual got a farmhouse (yeast blend) brown ale fermenting in one at the moment with nothing but a gas disconnect on to allow CO2 to vent. Not much will get in through the small hole. Not much of an issue if it does as its full of Brett yeast anyway.
     
  4. Dec 7, 2017 #4

    liamf89

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    Wasn't planning to ferment it under pressure just pump bit of co2 into it when I first put wort in to purge the keg then have a disconnect on the gas in side so any gas given of during fermentation will come out there threw tube placed in some star san.. Then after ten days transfer it to clean keg.. Connect gas to the one I'm using as fv and put a tube with two black disconnects on the out on both kegs and put bit of pressure in the fv corny to get beer flowing
     
  5. Dec 7, 2017 #5

    liamf89

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    Yeah that's basically what I'm thinking of doing not worried about carbing while it ferments or anything.does the yeast come out first when you start to transfer it to the next keg was thinking of using a jg valve inline so I can run the first bit with yeast and trub down sink or in Mason jar to harvest.
     
  6. Dec 7, 2017 #6

    Sadfield

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    That sounds like it'll work. The yeast stays set on the bottom of the keg, but it depends where the bottom of the dip tube sits in relation to the top of the yeast cake. I have a spare dip tube that is cut slightly shorter and at a 45 degree angle, for when I ferment in a keg.

    "Inspiration is the impact of a fact on a well-prepared mind" Louis Pasteur
     
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  7. Dec 7, 2017 #7

    liamf89

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    If I leave the dip tube as is on the bottom then it should draw the yeast out first so can run first bit of and then attach it to keg and transfer it. Can put wort between 2 kegs to allow head space
     
  8. Dec 7, 2017 #8

    Soton

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    If you are going to use a keg for fermentation but not ferment under pressure it’s still a good idea to use a spunding valve, that way the valve will allow the oxygen to be released and replaced with CO2 during fermentation and act as a airlock to stop air getting back in
    You would only need it set the valve at low pressur, just enough to keep the keg sealed.
    If you then transferred the beer into a well purged keg under pressure it would remain oxygen free and would very properly keep better for longer periods of time
     
  9. Dec 7, 2017 #9

    Soton

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    I ordered from AliExpress a longer gas in drip tube and if I use a keg to ferment in I slip a plastic tube over it so it’s cut a bit shorter from the bottom of the keg, I did this as I could not get a spare beer out drip tube and didn’t want to cut the one in the keg
    If you use a full size drip tube I would bottle the first couple of pints out then put the rest into a keg
     
  10. Dec 7, 2017 #10

    Sadfield

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    Yes, to both questions.
     
  11. Dec 8, 2017 #11

    peebee

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    I've also been looking into fermenting in a corny keg. Creating a "Nanny State" clone (DIYDog). But I want to take a different approach, fermenting and serving out of the same keg. Can't abide the term "cold crash", but a "spunding valve"... got to have one of them!

    My intention is to set the valve at 12-15PSI and charge the keg with the wort (OG 1.006-7ish - so there shouldn't be problems with loads of yeast) plus about 250g of dry hop pellets in two 300x70mm stainless steel mesh canisters, then allow to ferment for 5-6 days. Chill ("cold crash"? Blah!), vent the pressure, remove the lid to get the dry hops out, seal and pressure back up from a cylinder. And serve a few days later (no need to warm up, add priming sugar, and allow to condition - it should already be).

    Currently I worry about removing the dry hops. Am I going to be creating loads of foam when I try to take off the lid?


    My spunding valve uses a SMC AP100 02, a diaphragm type pressure release valve that was going cheap(ish) on EBay. I got the impression that the commonly used "poppet" PRVs open fairly reliably but are a bit dodgy about closing again, leading to erratic pressure control?
     
  12. Dec 8, 2017 #12

    foxy

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  13. Dec 8, 2017 #13

    JapanBrew

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    But at first you need oxygen in and around your wort. This helps the yeast propagate.
    But it should be no problem in fact it would be a way to push out the trub and then shut off the gas in part and let finish and carb in one shot. I would then transfer to a new keg after. That would really clear it up like a brite tank. You got my curiosity going. The only real issue would be is there would be more joints and hidden areas for yeast to hide. You could get around that by pumping the hot wort, above 75 degrees, into your keg. But with that, if the seals haven’t been changed to silicon it might be an issue.
    After I finish my kegs, I use oxyclean with 60 degree water the rinse well. After, I store my Starsan in the empty kegs when not in use.
     
  14. Dec 8, 2017 #14

    foxy

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    Not true that yeast needs oxygen in the wort, brewers yeast can ferment aerobically and anaerobically, a good healthy yeast starter can be pitched into wort that has been neither oxygenated or aerated.
    How about fermenting in the keg, running the gas line into the second keg, make up a spunding valve to release the pressure to whatever you set it at, (not to high ale yeast can get stressed under pressure) on the second keg, you then have a sanitized keg ready to transfer to.
     
  15. Dec 8, 2017 #15

    JapanBrew

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    The key word you said was “starter.” Most of the homebrewers are pitching dried packets of yeast. These need oxygen to start.
     
  16. Dec 8, 2017 #16

    foxy

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    Even dry yeast can ferment without oxygen, dry yeast is already packed with sterols, but it would be wise to re hydrate the yeast and the ferment probably would be better if a good vigorous shake of the wort.
    So don't UK home brewers use liquid yeast?
     
  17. Dec 8, 2017 #17

    henteaser

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    I'd suggest trimming the dip tube, say 2-3cm, and keeping it as a dedicated fermentor:

    - Pull clear beer from above trub with no disturbance of the yeast cake
    - You'll be dumping a litre or so of trub/yeast/beer regardless, so you won't "waste less"
    - Gravity samples won't be just trub (you'll want to taste these!)
    - Avoid risk of blockages if you dry hop heavily

    I'd also suggest switching down to 16l batches to allow for the smaller volume of the keg (which also means you get to brew more often!)

    When it comes to kegging, purge and pressurise a serving keg to the exact same pressure as your FV. Move the spunding valve over to the gas-in post of the serving keg, and CO2 line to the FV's gas-in, again, at the same pressure (I usually go for about 5 psi).

    Next, hook up the beer-out to beer-out line. At this point, both kegs will be in equilibrium, and no beer will flow. Slowly open the spunding valve on the serving keg until the beer starts to flow.

    ...and voila! Counter-pressured keg fill. Any carbonation you've built up during fermentation shouldn't foam out during transfer, and you'll need less time and gas to get up to the correct volumes once complete.
     
  18. Dec 8, 2017 #18

    henteaser

    henteaser

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    True.

    But there's a reason we call it the "Aerobic stage". There's no denying the presence of oxygen greatly effects this reproductive stage. More oxygen, more yeast in the later stages, better fermentation, better chance of good beer.

    True.

    Yeast don't need oxygen...

    ...or temperature control...

    ...or sanitary practices...

    ...or correct pitch rate...

    But are we after great beer, or pruno?
     
  19. Dec 8, 2017 #19

    Sadfield

    Sadfield

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    Yeast produce ethanol only under anaerobic respiration. Under aerobic respiration it produces lactic acid. Quite clever really, consumes oxygen in the wort and produces lactic acid and Co2, creating an environment that bacteria can't tolerate, then is free to continue to consuming all the available sugar anaerobically. The co2 it produces also lowers the pH by forming carbolic acid.

    "Inspiration is the impact of a fact on a well-prepared mind" Louis Pasteur
     
  20. Dec 8, 2017 #20

    peebee

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