First "Real" Attempt at Reducing Oxidation

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UncleD

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Well it's embarrassing to say that it's taken me about 20 batches of homebrew through my kegerator to determine that I think I have an issue with by brews oxidizing. I primarily brew west coast IPAs, and have found that shortly after kegging, they are fine. Nice golden color, aroma, and good flavors. As the weeks go by, the beer turns darker, loses aroma, and has a more earthy-sedimentary type taste. Based on similar experiences with other threads I've read, this sounds like oxidation. I also have no problem believing it's oxidation, because kegging has arguably been the most careless part of my brew process to date. I basically ferment in a stainless steel conical, and gravity drain (through an inline filter) into a corny keg with the lid off. I then toss the lid on, charge it with CO2, and call it good. A few weeks later, I'm quite disappointed.

After reading a handful of threads, I plan to implement a "closed transfer". I purchased a 1.5" tri-clamp to QD fitting for the top of my fermenter, and a spunding valve for the CO2 in port of my keg. I plan to transfer my current batch this weekend following this process:

  1. Fill keg with starsan solution, install lid, and attach transfer tube from "beer out" to a spare empty keg, and attached CO2 to force all the sanitizer out into the spare keg
  2. Connect the open end of the transfer tube to the racking arm of the fermenter
  3. Connect the CO2 to the top of the fermenter using adapter, set to very low pressure (2-3 PSI)
  4. Connect the spunding valve to the CO2 in of keg, adjusted for a very low pressure
  5. Open the CO2 valve to the fermenter, and then the valve on the racking arm
  6. Once all beer has been transferred, disconnect the transfer tube and spunding valve and connect CO2 to the CO2 in
  7. Purge the headspace by filling with CO2 and discharging with PRV in keg lid, do this 3 times
Does this sounds right? Anything obvious I'm missing that will likely end up in homebrew all over my kitchen?

Cheers!
 

day_trippr

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Pretty good summation. A couple of things to keep in mind:

- truly "filling" a corny keg can be moderately challenging, due mostly to the lid geometry. If you take the lid and set it PRV down on a countertop you are then looking at the crux of the problem: the PRV extends down aways and thus will trap the equivalent amount of air inside that lid cavity. I've read it measures around 3 ounces - which is a lot.

Most folks that are aware of this cut their gas dip tubes down to 3/8"-1/2" total length so they don't extend into the head space, which then allows tilting the keg to put the gas post at the highest point for venting. Others (me) ensure the end of the original length Out dip tube is properly located in its well at the bottom of the keg, then flip the keg up side down and fill through the gas post and vent through the beer post. It only take a brief bit of rocking to get the last bubbles out.

- when setting up your transfer gear, don't forget to purge the tubing etc! You don't want to shove a bunch of air into a nicely purged keg :)

Cheers!
 
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greywolf

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I ferment and serve from the same keg. No more oxidation issues. easy peasy.
 

Squirrels

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I like to use my fermenters co2 during fermentation to push the co2 out of the keg (pick up nickels). I hook the keg up for purging after fermentation has been rolling for a day or two. Otherwise, pretty much what I do.
 

Noob_Brewer

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I like to use my fermenters co2 during fermentation to push the co2 out of the keg (pick up nickels). I hook the keg up for purging after fermentation has been rolling for a day or two. Otherwise, pretty much what I do.
Yup agreed with this. If you hook up your blow off from the conical to the star san filled keg, the CO2 produced from fermentation will purge the star san out and your keg will be left with a serving keg full of "more" pure CO2 than what your CO2 tank can provide. When I do this (when I have a future serving keg available), the liquid out of the keg goes to a bucket. Once all the star san is purged, your bucket of star san will effectively function like an air lock as well and you can "see" when the active fermentation slows. I keep my fermentation vessel at relatively the same height as my purge keg when the fermentation CO2 is leaving the FV to purge the keg, because if it is dramatically lower than the FV, you have the potential to create a CO2 siphon and create a vacuum in the FV. I don't have a SS conical but a fermonster. the first time I did this, the keg was lower than the FV and to my amazement and horror when I checked on the fermonster, it was in the damn shape of an hour-glass lol. Good luck and Im sure your closed purging and transfers will help your oxidation issues a ton! Cheers!
 

Squirrels

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Yup agreed with this. If you hook up your blow off from the conical to the star san filled keg, the CO2 produced from fermentation will purge the star san out and your keg will be left with a serving keg full of "more" pure CO2 than what your CO2 tank can provide. When I do this (when I have a future serving keg available), the liquid out of the keg goes to a bucket. Once all the star san is purged, your bucket of star san will effectively function like an air lock as well and you can "see" when the active fermentation slows. I keep my fermentation vessel at relatively the same height as my purge keg when the fermentation CO2 is leaving the FV to purge the keg, because if it is dramatically lower than the FV, you have the potential to create a CO2 siphon and create a vacuum in the FV. I don't have a SS conical but a fermonster. the first time I did this, the keg was lower than the FV and to my amazement and horror when I checked on the fermonster, it was in the damn shape of an hour-glass lol. Good luck and Im sure your closed purging and transfers will help your oxidation issues a ton! Cheers!
I usually just push the starsan into another keg through the liquid posts and that acts as an airlock.
20200731_221613.jpg
 
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UncleD

UncleD

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Great feedback guys, thank you. I will most certainly report back after my first try at this!
 
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UncleD

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Ok went pretty smooth, not the total disaster I imagined. There were 2 items that I will need to resolve next time:

1. The transfer line hose was a bit too bit for the QD barb, so it was leaking a bit even with the hose clamp tight
2. I didn't have the spunding valve adjusted to release at a low enough pressure, so the transfer appeared to have gotten "stuck". I had concerns that my racking arm was clogged or something like that, so I disconnected the transfer line to check, and found that it was not clogged, I just need to allow the pressure to vent at a lower pressure. This may have introduced a bit of oxygen into the line. Oh well, all part of the learning process. I'll get those items fixed next time.

Most importantly, here's the color at the time of transfer, which is cold crashing in my kegerator and I will start to drink after a week or so. I plan to monitor the color and flavors over the next month or so to see if this process has reduced the oxidation problems.

IMG_7553[1].JPG
 
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