Someone dropped a banana in my German Lager

[Pallyjim]

Hey guys.
I've just done my first BIAB lager (done a bunch of ales before that).
2kg German Pilsner, 375g light Munich, with 10g halertau at 60,10,0. Used my first Wyeast, the WLP830 German lager. Started at 1.042, finished at 1.012.
I've heard of banana as an off flavour mainly from fermentation temps, but I've got good temperature control. Had it at 11c for 3 weeks, a rest for 2 days and a cold crash.
The banana flavour is so strong, is it the style, something gone wrong. Thoughts?

 

[Adr_0]

Diacetyl?

 

[manticle]

How much yeast and what was pitching temperature?

 

[Pallyjim]

I used the whole liquid sachet thing for the 10l batch. From memory it was pretty cold, under 15c

 

[MitchD]

3 weeks primary is too long. It should be ready for a d-rest by the end of week 1, a a couple days at 16-18 but the taste test will be the guide.

At 3 weeks the yeast are done and ready for a nap or or starting to autolyse so if it is diacetyl youll be struggling to clean it up.

 

[Matplat]

3 weeks primary is too long. It should be ready for a d-rest by the end of week 1, a a couple days at 16-18 but the taste test will be the guide.

At 3 weeks the yeast are done and ready for a nap or or starting to autolyse so if it is diacetyl youll be struggling to clean it up.

That goes against pretty much everything I have read about fermenting lagers....

3-4 weeks in primary is normal for a lager, and autolysis takes much longer than that.

 

[mstrelan]

Did you make a starter? What was the production date of the yeast? Could be an under pitch.

 

[MitchD]

That goes against pretty much everything I have read about fermenting lagers....

3-4 weeks in primary is normal for a lager, and autolysis takes much longer than that.

Care to list your sources?
If your lagers take 3-4 weeks to hit fg you are doing something wrong. Either pitching rates oxygen or you just don't know what is happening in your fv.

http://braukaiser.com/wiki/images/archive/7/73/20090308044250!Lager_fermentation_charts.gif

 

[Lyrebird_Cycles]

Why are we arguing about diacetyl when the OP is more likely describing excess esters?

 

[Lyrebird_Cycles]

At 3 weeks the yeast are done and ready for a nap or or starting to autolyse so if it is diacetyl youll be struggling to clean it up.

If your yeast are starting to autolyse after three weeks at 11 oC :

you just don't know what is happening in your fv.

 

[MitchD]

True there are probably esters but the op hasnt put the yeast through a proper fermentation process either so each bit of advice will add up to a better final understanding. I see you noticed the error of your original post and eddited it quickly. Then had a cheap shot with some creative interpretation of my posts.

 

[manticle]

Why are we arguing about diacetyl when the OP is more likely describing excess esters?

Apart from 1 post asking if diacetyl is the culprit for what the OP is tasting and mention of d-rests as possible part of fermentation regime, I don't see much about diacetyl that could constitute an argument.

Questions about underpitching, temperature and yeast health are relating to development of isoamyl acetate.

 

[kaiserben]

3 weeks primary is too long.

Say what now? I'll regularly leave ALES in primary for 3 weeks. Lagers more like 4 weeks. This is most definitely not the problem here.

It would have been a slight underpitch (even more likely the problem if the vial was a few months old) and without knowing the OP's processes, I'm guessing it was also lacking enough oxygen to keep the yeast happy.

 

[Adr_0]

Why are we arguing about diacetyl when the OP is more likely describing excess esters?

Lighten up buddy, just offering a question - some people could perceive the sickly sweetness as crossing over into banana, and it is extremely common.

 

[MitchD]

The point I was trying to make was about fermentation time it wasn't to do with how kong you long you leave your beer on the cake, MHB will come along soon enough and set every one straight on that.

My point was that if it takes 3+ weeks to hit fg you are doing something wrong. White labs for example provide attenuation estimations. If you do some some research you will see that they estimate 50% in 60hrs or 2.5 days. How does it take a further 18.5-25.5 to reach fg? If it takes that long you have done something wrong.
http://www.whitelabs.com/yeast-bank/wlp830-german-lager-yeast

 

[mtb]

Where was it said that it took 3wks to reach FG?

 

[kaiserben]

Fair enough, MitchD.

But I don't think it necessarily took that long to ferment. He just left it at 11C for 3 weeks.

 

[kaiserben]

And it's important to remember that yeast don't always follow a schedule.

Coincidentally my most recent lager used a yeast I'd never used before (Yeast Bay's Franconian Dark Lager strain). It was taking a long time to get where I wanted (it actually stalled for a while, so I bumped the temp up a few times). I actually emailed the manufacturer/microbiologist about it (and we exchanged a few emails back and forth from there). Anyway ... the end result is that it took 3 weeks to reach 66% attenutation. The microbiologist said that wasn't what they'd usually experienced, but that it happens from time to time. I gave it 5 days for D-rest (so 4 weeks by this stage), then chilled and lagered another week (so 5 weeks at this stage). The resulting beer was great.

I used the same strain (which I'd built up previously from the original package) in something I've got fermenting right now and it took 9 days to get to 50% attenuation when sitting at 8.9C. Since then I've given it a "fast ferment" D-rest to get it to finish.

Other strains I've used have got to 66% attenuation in 6 days, followed by the fast-ferment rest at 18C for a few more days till finished.

 

[MitchD]

It probably didnt, but he wouldn't know and when he did do a d-rest the yeast were most likely asleep so a 2 day rest wouldnt have had the desired result in absorbing diacetyl.

My method is:
Pitch 2c under ferment temp
Monitor fv action after active fermentation begins.
4 days after active fermentation take a sample. Monitor action.

When its under 10 points from fg raise to 16-18 for a d rest. Probably day 6 after pitch/active fermentation.

After 2 days taste the beer, diacetyl? Leave warm, none? Check fg it should be ready.

Rack off and lager (best practice) or drop the temp to lager temps and bottle when clearing up (how I do it)

I went 3rd state then 2nd at nats last year. 1st at state the 8th at nats this year with a helles. No mention of diacetyl or eaters on my score sheets.

 

[kaiserben]

That's a very good point about the yeast already being asleep (if he left it 3 weeks) and the D-rest. And some esters would also normally get cleaned up during a D-rest, right? (although it's best to avoid creating esters in the first place, which means a pitching the right amount of yeast and good oxygenation).

It sounds like your methods are pretty much same as how I do it. I gun for 66% attenuation, rather than 10 points from FG, which is possibly about the same anyway.