Fermenting in a polypin / bag as cheap oxygen free option when kegging

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floydmeddler
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Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by floydmeddler » Sat Mar 06, 2021 6:07 pm

Recently, I've been thinking about cheap ways to ferment and rack beer without the presence of oxygen. Have just bought a Fermzilla but would like other options too as they're pretty pricey!

I was in the brewery a few days ago looking through some bits and pieces and came across an old 20L polypin. Looking at that old polypin, I thought.... maybe there's an idea here! So. This is what I did today:

Brewed a double Citra / Apolo IPA hop bomb. 10L in total. Should come in at around 8.5%. :-) Transferred it to the polypin and pitched Kveik yeast (I want this by next wknd :-))

See attachment for set up. I've used 3/8 beer line and a 10L growler style keg.

The CO2 will come out of the pin and purge the keg of oxygen. No point wasting it! When the ferment is over I'll disconnect the keg then reposition the bag in a brew fridge so that the tap is at the bottom. I'll then crash cool for a few days without the worry of oxygen being sucked in.

When it comes to kegging, I'm planning on reconnecting the 3/8 beer line to the polypin (fits beautifully by the way) and attaching it to the beer 'in' on the keg. Will release the pressure valve on the keg then rely on gravity to do the rest.

In theory then, all in all, this should be an oxygen free transfer without the need to pump CO2 into a fermenter or set up a closed loop system.

I was planning on dry hopping (somehow) but ended up adding all the Citra and Apolo as steeping additions as I hadn't settled on a method for that yet. Magnets could be the way forward? Have seen that done lots and it seems to work really well. Maybe next time if this is a success.

Has any one tried or considered this method before? What are your thoughts on this as a method for oxygen free fermentation and kegging?

Cheers dudes,

Floyd
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McMullan

Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by McMullan » Sun Mar 07, 2021 11:45 pm

Looks like a good strategy. It might be a pain to clean the polypin after a primary fermentation. I’d cover it to avoid any skunking due to light interacting with hop compounds.

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MashBag
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Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by MashBag » Mon Mar 08, 2021 9:31 am

I like your thinking and I love experimentation.
An issue might be the unstable sediment will blizzard like a snow-globe when you invert. Not to mention being the first to race down the transfer tube.
Could you stand the tap on a bean tin, so when it is upside-down it still 'just' above the sediment. Maybe a tuna can ?

"Skunking" - its for drinking next week. Never experienced that - how quick can that set in?
I agree cleaning will be a PITA - such a cry for TFR I have never heard before.

McMullan

Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by McMullan » Mon Mar 08, 2021 11:32 am

MashBag wrote:
Mon Mar 08, 2021 9:31 am

"Skunking" - its for drinking next week. Never experienced that - how quick can that set in?
It depends on the light source and the beer/hop level. It can take as little as 30 minutes :shock: Some people - mainly those accustomed to drinking big brand commercial piss water - actually prefer a little light struck flavour (skunking) in their beer. They don’t detect it as a flaw. Instead they brag about how their home brew is as good as commercial crap :roll:

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Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by MashBag » Mon Mar 08, 2021 11:41 am

McMullan wrote:
Mon Mar 08, 2021 11:32 am

It depends on the light source and the beer/hop level. It can take as little as 30 minutes :shock: Some people - mainly those accustomed to drinking big brand commercial piss water - actually prefer a little light struck flavour (skunking) in their beer. They don’t detect it as a flaw. Instead they brag about how their home brew is as good as commercial crap :roll:
"big brand commercial piss water" Very good - I may have to steal that one!

"Actually prefer a little light struck flavour" - got to get your flavour where you can.

I really didn't think it was that quick. I always ferment & store in the dark of the brewshed so perhaps that why its never happened.

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floydmeddler
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Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by floydmeddler » Mon Mar 08, 2021 7:55 pm

I covered the pin with a blanket so no sun. If I do this again, it'll all be done in a brew fridge.

Wow, that was an active ferment. Steady powerful stream of bubbles for a good 48 hrs then nothing. Was a real source of entertainment for my kids (and me). Kveik has done its job nicely. So far so good!

Will give it another 24 hrs to clear up then put it into a brewing fridge to crash cool. After a day, I'll use a carbonation cap to add gelatin through a bottle which I'll be able to co2 purge using the leftover co2 in the polypin. Will then reposition the pin so that tap is at the bottom. Will keg 24 hrs after that and force carb for another 24 hrs. With regard to sediment entering the keg, I'm expecting a bit. Shouldn't be an issue though hopefully. Fingers crossed I'll be having a glass at the wknd. Can't imagine I'll be having too many at this % though!

One thing that I've been very happy to see is that the krausen was VERY low. Maybe this is a Kveik thing? I'd confidently ferment 17L in there next time.

And yep. I'm concerned about the cleaning too. Could be tricky.

Fingers crossed for more success!

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Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by MashBag » Tue Mar 09, 2021 11:22 am

Fingers crosssed and keep us posted. What yeast did you use please?

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Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by floydmeddler » Tue Mar 09, 2021 8:01 pm

I went with Kveik. Mainly so that I could keep the set up in the kitchen to keep an eye and not have to worry about temp fluctuations. That yeast is a serious work horse!

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Re: Fermenting in a polypin / bag as cheap oxygen free option when kegging

Post by floydmeddler » Thu Mar 11, 2021 5:53 pm

Well, it's in the keg. Transfer was pretty slow which I didn't mind. However, getting out the last litre or so was messy as you can imagine. Left more behind than i'd have liked, but not much. A floating dip tube would have completely sorted it, but I can't see how one could be fitted to the outlet. I'd 100% make this a regular method if I could.

Cleaning was a doddle. No caked in bits to remove.

All in all, I'm happy that I gave this a shot. Oh... and the beer tastes great!

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