Unintended banana flavor - what to do differently?

[nrjones89]

What am I doing wrong, guys? I did a Hefeweizen last winter because I kept bitching about how I can't find Paulaner... be careful what you wish for... I've been cursed by the dirty banana! Ever since, all my beers have been overpowered by banana esters with the exception of a blonde ale fermented with nottingham. I have been doing saisons and Belgian ales. The first saison was brewed with 3724, and fermented at around 75F. It was kegged, and at higher carb levels, the flavor was a little more champagne/orange-like.

The saison was overpowered by a banana flavor - it was reduced at higher carbonation levels. The blonde and dark ale, which used the same base wort, were not. I used Nottingham for them. The Belgian pale ale was fermented with 1214; I was going for a more sessionable abbey-inspired ale, and I wanted some yeast character, anything but banana. I was kind of hoping for something like chimay, so I fermented it in a freezer at 60F, and the fermentation temperature was around 65F. I ramped up to 72 toward the end of the fermentation. Should have been more nutty, right? Nope. Straight up liquid banana bread. It's not just me, saying that, either. To my palate, as far as I recall, it doesn't taste like the same banana flavor as I had in the weizen or the saison; I'm guessing that has more to do with the grainbill and balance.

Both the saison and Belgian were fermented in the same vessel - a PET carboy that was cleaned with PBW. The beer line did at first add a slight off flavor if beer sat in the line for longer than 30 minutes. That has dissipated. I didn't clean my keg super thorough, but my blonde ale was the last beer I brewed and so it couldn't have been that. Clearly something is going on with the fermentation and it must not be temps. I don't really take any measures to aerate wort before pitching and I usually do not make a starter with the liquid cultures. I'm thinking that probably has something to do with it.

 

[specharka]

PET carboys do get saturated with volatile organic compounds, and can be difficult to effectively sanitize. But all POF+ yeasts will throw off a little isoamyl acetate, and under pitching Belgian yeast will promote that. I would recommend pitching more yeast, using a POF- yeast strain (like WLP644 for Belgians) and if that doesn’t help, replace your beer lines and switch to glass carboys.

 

[specharka]

Duplicate comment. Whoops.

 

[couchsending]

Some Hefe yeasts can survive multiple acid/caustic cycles in professional settings. I’d think you have some living somewhere in your gear.

 

[thehaze]

I am also thinking sanitation, as I did 3 hefes in the course of 4 months out of 15 batches, and none had banana, besides the hefes.

 

[nrjones89]

Some local brewers think I stressed the yeast and recommended starting warm with estery yeasts and then ramping down to cooler toward the end.

 

[dmtaylor]

Many Belgian yeasts produce banana. You might want to try different yeast. Also, I find that in many (but not all) cases, the banana fades quickly within a couple of months, so if you can hold off for a while, you might find the banana fades out significantly or entirely.

Nottingham doesn't produce any banana. It's a good clean yeast. Occasionally produces a peach flavor but that is all.

 

[Jayjay1976]

I wish all my gear would get infected with hefe yeast, I love banana esters.

 

[nrjones89]

I agree, I think I should try another yeast. I might try the Danstar Abbey yeast next time I do that style. I have stuck with wyeast 1214 for all my abbey style ales. I am chalking it up to underpitching/not creating a starter for now, but it might well just be that yeast strain.

Jayjay, I have never had a probably getting banana esters to style. The problem is always balance. Bubblegum Hefeweizen, banana flavored abbey ales and Belgian saisons, etc. The problem is consistent with liquid yeast. I always get good results with dry yeast. My problem is that I haven't been making starters, so I am probably underpitching.

 

[Jayjay1976]

...The problem is consistent with liquid yeast. I always get good results with dry yeast...

This is a very interesting point. I have only brewed once with dry yeast, excellent result but I didn't contribute that to the yeast. I think I should probably start using dry yeast when I can.