Someone dropped a banana in my German Lager

[kaiserben]

I just remembered (and confirmed via my old brew sheets) that I had a batch of Munich Dunkel with WLP838 that had massive smell and taste of banana at one point. At the point I'd slowly brought it up to D-rest temperature it was really overpoweringly bananary (is that a word?).

I held it at 18C for a further week. Then started to chill it down. At some stage while it was chilling I tasted it and it was horrid and sulfury. About a week later I bottled it. Carbed it for 3 weeks at room temp. Then put all bottles in a fridge for extra lagering.

I tasted the first one maybe a month after it had gone into the fridge: Beer was okay. All sulfur gone. Banana gone, but it still had some fruity esters.

I tried a bottle every so often and 3 months and 3 weeks after it had been bottled I no longer detected any esters and I was happy with the beer.

So maybe a hint there for the OP to give it a few months of lagering in bottles/keg before giving up on it.

EDIT:

And that was with the correct pitch of yeast, plenty of pure oxygen, ferment temp of 10C. So nothing I'd expect to throw heaps of esters.

It's the only time I've noticed banana. I've got sulfur before and since, but only during active fermentation.

 

[Matplat]

This is the first reference that comes to mind:

http://howtobrew.com/book/section-1/what-is-different-for-brewing-lager-beer/additional-time

 

[mckenry]

Wow - who would have thought a banana could get everyone hot under the collar? hahaha
To the O.P. 'banana' is an ester in beer, which is a fault in lagers, but enjoyed in most wheaties and some ales. You probably already know this, but doesnt hurt for future reference when someone might be searching this problem.

I tend to agree with those that are pointing the finger at yeast pitch rate, temperature and oxygen. Temp you have under control, but even doing a small batch with one smack pack or vial can be an underpitch, leading to said esters.

Also, there may have been some confusion around this '3 weeks' was or wasnt it fermented by then, but you wont achieve much raising the temp after the yeasties are fingered from battle.
i.e. do it while the yeast is still working - IF you have to.

 

[Pallyjim]

So what I hear everyone saying is that I shouldn't brew a lager and then go away on holiday leaving it in the fridge.
I've Brewer lagers before and left them for similarly long periods in primary.

I'm still wondering if the bananary (good word!) flavours could have come deliberately from the yeast and style, or are they just off.

Kaiserben, I think you're right. Had a taste yesterday and the off flavours are already less noticeable.

Lessons learned: be on top of my lagers more, rest earlier, yeast starter always!

 

[manticle]

Banana is not part of the intended profile, no.

 

[n87]

So what I hear everyone saying is that I shouldn't brew a lager and then go away on holiday leaving it in the fridge.
I've Brewer lagers before and left them for similarly long periods in primary.

on the contrary, Holiday is the perfect time for a lager, just make sure you have it lagering before you leave.
I try to leave my lagers lagering for atleast 2 weeks (usually ~6).

 

[dannymars]

on the contrary, Holiday is the perfect time for a lager,

I agree, I'm only holidays next week until mid December.... I have 60L of Vienna lagering away nicely, initial taste indicates I'm onto a belter.... should be crackingly good when I get back