Lagering in a PET Fermonster

[Brewer #450121]

Would anyone have thoughts/recommendations on lagering a Maibock for 3 months in a PET fermonster? This will be the primary fermentation vessel so will be on yeast for this 3 month time frame. I am ok with managing pressure during the temperature reduction to the lagering temp. Thanks

 

[Minbari]

No reason that shouldn't work

 

[Brew Cat]

it would be better to lager in the keg for that long
you should transfer under pressure and then store with slight pressure'

if you bottle then cold crash and lager in the bottle

https://byo.com/mr-wizard/trub-in-the-secondary-fermenter/

 

[J A]

Don't lager on the yeast trub. Find a way to transfer to secondary. You'll regret 3 months on dead yeast.

 

[BarbarianBrewer]

I think 3 months on the yeast & trub (even at lagering temps) is pretty close to, if not over, the edge. But I feel that fermenting in plastic that long is the main reason not to do it. PET will allow oxygen permeation which will oxidize the beer. When I bulk age a beer (4+ months) I always transfer to a glass carboy plus minimize the headspace.

 

[The Brew Mentor]

I have used the Vintage Shop fermentors for longer time storage of wine without any oxidizing issues.
They claim on their site that their fermentors are not permeable.
That being said, I prefer stainless steel or glass for longer term holding.
Also, I'd definitely transfer off trub.
Cheers
Brian

 

[Brewer #450121]

Thanks everyone for the replies I will definitely get this off trub and into a keg

 

[Donoroto]

Thanks everyone for the replies I will definitely get this off trub and into a keg

…or at least into some other vessel, like a fermonster. As you see, the PET isn’t a concern, the yeast is.

 

[J A]

Thanks everyone for the replies I will definitely get this off trub and into a keg

I always have a problem lagering in a keg...by the time I get done "testing" for quality, there's not much left by the time it's completely done.
I end up using quicker methods to clear it and get it pouring clean. I'll ferment with a big pitch and O2 and nutrient (yes, even with dry yeast) to get it done relatively quickly and cleanly and crash it in the tank for a week or so to get good yeast drop. Then I keg with a fair amount of BioFine and let it sit for a few days before pulling a couple of pints of yeasty beer off. Then with another week or so of clearing, it's pouring crystal clear and very proper-tasting.

 

[Dave Y]

I always have a problem lagering in a keg...by the time I get done "testing" for quality, there's not much left by the time it's completely done.

I find that keeping an acceptable variety on tap helps in this regard. The downside to his approach is when the neighbors don't do their part !
I don't usually cold crash that long, I try to get 2 consecutive days under 40F and that usually does a very good job of cleaning things up, but if I can't get under 40, I will end up with sediment in the bottom of the keg. Last year I found out that Mangrove Jacks Bavarian Lager strain will ferment well into the 40's - I think I saw airlock activity down to 45F.

After 2 days I'll start harvesting yeast until I get mostly beer. It usually takes me a couple days to get all the yeast out - I do 2-3 dumps, close it up and let it rest, usually overnight. After I get mostly beer in the dump, I let it rest at least the rest of the day or overnight, and keg. It's still an in progress process because I now have a measure of climate control.

 

[J A]

It usually takes me a couple days to get all the yeast out - I do 2-3 dumps,

I find it really difficult to dump yeast after I've closed off the fermenter and carbed up. If I take the time to bleed all the pressure off and leave the fermenter open, I can get a fairly clean trub dump but that risks O2 incursion as the volume drop. If I try to keep just the least bit of pressure and keep the fermenter closed, I'll get a pint of yeast and then it'll be squirting yeasty beer. I could go further and waste some more beer but I usually just clear a pint or two of the worst of the trub and then proceed to transfer, using my racking arm angle to keep out of the trub zone. I don't get much yeast in the transfer but there's a little.

 

[Minbari]

I find it really difficult to dump yeast after I've closed off the fermenter and carbed up. If I take the time to bleed all the pressure off and leave the fermenter open, I can get a fairly clean trub dump but that risks O2 incursion as the volume drop. If I try to keep just the least bit of pressure and keep the fermenter closed, I'll get a pint of yeast and then it'll be squirting yeasty beer. I could go further and waste some more beer but I usually just clear a pint or two of the worst of the trub and then proceed to transfer, using my racking arm angle to keep out of the trub zone. I don't get much yeast in the transfer but there's a little.

I always hook up the co2 line and get the air lock bubbling first

 

[Dave Y]

I find it really difficult to dump yeast after I've closed off the fermenter and carbed up. If I take the time to bleed all the pressure off and leave the fermenter open, I can get a fairly clean trub dump but that risks O2 incursion as the volume drop. If I try to keep just the least bit of pressure and keep the fermenter closed, I'll get a pint of yeast and then it'll be squirting yeasty beer. I could go further and waste some more beer but I usually just clear a pint or two of the worst of the trub and then proceed to transfer, using my racking arm angle to keep out of the trub zone. I don't get much yeast in the transfer but there's a little.

I use Blichmann’s yeast harvesting kit. It has a co2 port to charge the bottle, connected to the tri-clamp port. Charge to same or just a bit more than the fermenter, open the dump valve, bleed off just enough pressure to start the flow and tighten back up. Easy-PEASEY.

But, it does “disturb “the beer just a bit so I can get about 3 fills, typically need 5 to get mostly beer, so it takes more than one harvest to get there.