Caught by surprise.

[GilaMinumBeer]

I never realized until recently that, all my beers have the same identical aroma. From the Stout to the Apfelwein. 6 taps. One of the kegs is barley a month on the gas and it too has the same aroma.

Sweet malty hint, bready, yeasty. Almost corn like hidden under a malty, yeasty, note.

Not infected. Beer lines are the higher end lined against gas/odor permeability. No beerstone.

Flavor is distinctly different between the taps but aroma is identical on every one, no matter how much is poured out.

My serving system gets broken down after every keg. Faucets, disconnects, shanks, and lines get a soak in hot PBW for 12 hours. Kegs get cleaned in similar fashion and are sanitized with StarSan.

My only guess is how I primary. I usually primary only but for an extended time. 3 weeks to a month. I usually use finings and always cold crash for at least 2 weeks at around 30*F.

Suggestions?

All my gas lines are clear and clean of debris. But, I do have a distribution bar and I wonder if there could be some gunk in there considering it feeds all the taps.

My thoughts are conflicted on this. Only because I dread using a carboy secondary to test the theory.

I have also had some supicions of the use of the bucket liners but the idea that the liners attribute loss of aroma and hop flavor do not calculate unless "something" could be leaching from this food grade liner to mask them. But then again, I have a beer or two brewed prior to using the liners and it too has this peculiarly similar attribute.

 

[Grizzlybrew]

Almost corn like hidden under a malty, yeasty, note...

My only guess is how I primary...

...My thoughts are conflicted on this. Only because I dread using a carboy secondary to test the theory.

Corn sounds like DMS, right?

My first thought was your primary ferm vessel. What are you using? I kind of assumed plastic buckets from the issue. If that's the case, then hell, even my glass carboys (which shouldn't be permeable) seem to retain aroma until they get a PBW or Oxi wash.

Why not just use a glass carboy for your primary? If the primary plastic ferm vessel is the cause, it's not going to matter if you secondary, the aromas will have already been shared from the previous batch.

Hopefully I understood correctly...

 

[GilaMinumBeer]

Corn sounds like DMS, right?

My first thought was your primary ferm vessel. What are you using? I kind of assumed plastic buckets from the issue. If that's the case, then hell, even my glass carboys (which shouldn't be permeable) seem to retain aroma until they get a PBW or Oxi wash.

Why not just use a glass carboy for your primary? If the primary plastic ferm vessel is the cause, it's not going to matter if you secondary, the aromas will have already been shared from the previous batch.

Hopefully I understood correctly...

Yes DMS leads to corn but, 90 minute boils, no cover, and it's an aroma only. The flavor is not corn.

I "could" use my 5 gal carboys for a primary to test theory as long as I manage blowoff properly.

I don't suspect this is a transfer from the ferm vessel, but suppose it could be. As I said flavor is not affected. All the beers smell the same, even prior to the first sip. If anything, I am speculating about the duration of primary. Not callling it autolysis tho'.

 

[Grizzlybrew]

Yes DMS leads to corn but, 90 minute boils, no cover, and it's an aroma only. The flavor is not corn.

I "could" use my 5 gal carboys for a primary to test theory as long as I manage blowoff properly.

I don't suspect this is a transfer from the ferm vessel, but suppose it could be. As I said flavor is not affected. All the beers smell the same, even prior to the first sip. If anything, I am speculating about the duration of primary. Not callling it autolysis tho'.

DMS - heard

...or brew a smaller test batch.

I ferm'ed a spiced wheat in a plastic bucket and ended up throwing it away. The next few subsequent beers picked up the odor. They didn't taste spiced, but you could smell faint hints of cinnamon. Autolysis is interesting, but even at a month and a half shouldn't be a problem. Someone told me the other day to scratch a rubber bung and smell it. He said if that's what your beer smells like, you've got autolyzation.

Maybe you can just call it your "house" aroma...

 

[menschmaschine]

None of those things jump out at me. Even the extended primary. Lots of brewers primary for 3 weeks or more. Maybe if you had a lot of trub in the fermenter there could be an off-flavor issue.

Maybe try bottling a couple on the next batch... like with carb tabs or something. At least then you can see if it's a keg sytem issue.

 

[jmick]

just throwing this out there, but could it be your glassware?

 

[lamarguy]

Suggestions?

About a year ago, I had a "peculiar" aroma that showed itself after a beer was on tap for one to two months. It certainly didn't ruin the beer, but it was detracting. This happened to three or four batches in a row. They never really developed an off taste, but the aroma changed for the worst after a bit of time.

My lines are cleaned regularly too, so I looked at my cold-side process. I isolated the problem to a bit a wild San Antonio yeast inoculating my brew *just enough* to cause an odd aroma after extended aging but not enough to effect the flavor. I was brewing with the garage fan on during the wort transfer. :cross:

I've since transferred in a completely closed environment (zero chance for air exposure) and the problem went away (I still use the fan ). Not saying that is your problem, but it's worth considering. Invite an experienced nose over and ask for feedback. Objectivity is often just as valuable as in-depth knowledge about your process.