Record Setting 8-Month Ferment

[Picobrew]

Haven't been on here in ages. Miss yall.

So I brewed an all grain pilsner-ish recipe back in December 2011, using 2565 Kolsch yeast. I was (and am) in the thick of a new business, and let it linger, and linger, and linger, and then I basically gave up. Yes, it was still in the primary on the yeast cake all this time. So it goes.

I normally ferment in the primary for a month, so long primary times are no stranger to me, but I let this baby go 8 months. I thought for sure it would taste like crap - I have been conditioned to fear the autolysis bogeyman.

After a taste, I decided to keg and carbonate it.

This beer is actually semi-drinkable! It is crystal clear; the hop flavor is diminished quite a bit; but the only real off flavors are a slightly vinegary flavor and a semi-strong green apple flavor. Could this be acetaldehyde? It fermented so long I thought the yeast would consume acetaldehyde. I am a bit perplexed.

I haven't experienced this flavor in any of my other brews, and am having a hard time describing it - but I don't think it is the super-scary autolysis flavors that I have heard described.

Do any of you biologists have any ideas about this? Has anyone here ever fermented this long?

 

[PoorYorick]

Id actually really like to try that Sorry I don't have any other input

 

[masonsjax]

I have a Rye Pale on tap right now that sat on the cake for close to 8 months (not on purpose, I was busy too). The carboy was kept at 62-65F the entire time. I detect zero off flavors in the beer, although the hop character is nil, and those subtle rye aromatics are gone too. It's a little on the bland side now, but more than drinkable.

 

[diegobonatto]

Bacterial contamination? This could explain the vinegary and green apple flavors....