Acetaldehyde (green apple flavor) coming AFTER fementaion is complete

[mmmatt]

I brew on a 3 bbl electric system and use plastic conicals. This beer uses Lallemand's lovely Belle Saison yeast.

Brewed a really big Triple using the Belle Saison. Fermented to just under 12% ABV which was more attenuation that what I was expecting based on software. I don't have my info in front of me this second, but it was an over 1.1 OG and down to 1.011 if I remember right. Nothing fancy, tons of grain (~125 lbs per bbl) and some belgian sugar.

After about a month in the tank it was lovely in every way and at that time I acquired a Kendal Jackson oak chardonnay barrel. Decided to use this beer for the barrel and transferred 53 gallons into the barrel and the other 40-ish stayed in the tank. My intent has been to blend the barreled and unbarreled beers together in my brite.

After letting the 40 gals sit in the tank for a month or two I decided to put it into kegs (uncarbed) for storage until I was ready to blend. During the second transfer I pulled a sample and it was straight up jolly rancher. Very strong green apple. I have never had Acetaldehyde but reading up it seems it is due to un-finished fermentation. I cant imagine this is unfinished. The beer that I transferred to the chard barrel is simply epic and not in anyway suffering the same fate.

So any ideas how this happened? I cant say enough how much I regret not kegging the ballance right away, but still it is a mystery to me. Will it age away? I'm thinking about bottling 10 or so gallons of the affected beer and popping one every now and again to test and see if it improves. This beer is due to be released as my holiday beer, so a month or so away from release.

Thanks in advance
Matt
D14 Brewery & Pub

[beerman_smitty]

Hey Matt,

Shoot me an email today if you like. I have some insight on this matter.

Nick

Fermentation Outreach Specialist, UW-Madison
nsmith35 at wisc.edu

[Yeast]

I'm hoping that you pushed the beer out with a CO2 push instead of admitting air into the fermenter? However even without that, be aware that polyethylene does have a micro-oxygen permeability and keeping a beer in the plastic conicials may have oxidized your beer and allowed acetaldehyde to reform in that stored beer. I believe you are correct in stating that you should have transferred that beer into kegs when you transferred the rest of the batch to the barrel.

That beer may not be lost since the acetaldehyde can be re-metabolized with an active fermentation. While your conicals are fine for active fermentation, do plan on transferring ASAP after the ferment is complete.

That would be best case but I would think you would be overwhelmed with trans-2-nonenal if oxidation was happening

[mmmatt]

I'm hoping that you pushed the beer out with a CO2 push instead of admitting air into the fermenter? However even without that, be aware that polyethylene does have a micro-oxygen permeability and keeping a beer in the plastic conicials may have oxidized your beer and allowed acetaldehyde to reform in that stored beer. I believe you are correct in stating that you should have transferred that beer into kegs when you transferred the rest of the batch to the barrel.

That beer may not be lost since the acetaldehyde can be re-metabolized with an active fermentation. While your conicals are fine for active fermentation, do plan on transferring ASAP after the ferment is complete.

Thanks for the comment. Can't push the plastic conicals. I syphoned off the top, so yes I did draw o2 into the tank. I wasnt really thinking of oxegenation in my tank, so that could certainly be it. In the past I have purged with canned co2 or added some sugars to get the yeast going again but was thinkinng more about bacteria and wild yeasts and didnt feel the need with this big a beer. Feeling like a live and learn moment!!!

One of my local "competitors" has already contacted me about getting it under a scope and plating it for me. Isn't the brewing comunity awesome?

Thanks everyone!!

Matt

[mmmatt]

That would be best case but I would think you would be overwhelmed with trans-2-nonenal if oxidation was happening

Thanks for your response. so if not likely oxygenation, then bacteria? It has to be something that happened after my initial transfer of part of it to the barrel. There was nothing on the surface of the beer in the fermenter. No other off smells/flavors either. Unless it is buried under the apple. I'm a home today or I would verify.

[Yeast]

Thanks for your response. so if not likely oxygenation, then bacteria? It has to be something that happened after my initial transfer of part of it to the barrel. There was nothing on the surface of the beer in the fermenter. No other off smells/flavors either. Unless it is buried under the apple. I'm a home today or I would verify.

Another thing thats got me thinking. Since you're down the street from us. We had a problem with zinc deficiency causing shit fermentation before maybe you too since its such a high gravity beer that could explain the apple too. Yeast really need the o2 and trace nutrients to make a high grav beer like that with no off flavor. I would think you would notice it right away at EOF but who knows. Did you drop the yeast out before transfer to barrel or rack away from the yeast?

[mmmatt]

Another thing thats got me thinking. Since you're down the street from us. We had a problem with zinc deficiency causing shit fermentation before maybe you too since its such a high gravity beer that could explain the apple too. Yeast really need the o2 and trace nutrients to make a high grav beer like that with no off flavor. I would think you would notice it right away at EOF but who knows. Did you drop the yeast out before transfer to barrel or rack away from the yeast?

I didn't drop yeast until after the partial transfer. I dropped it before the final transfer however. I do lots of high gravity beers without issue, and remember the other half of this batch is very good, so this is not having to do with my initial ferment I don't believe. Well, this is probably the highest ABV I have done, but I pretty commonly go to 1.1 OG . My first Tripel Saison (called Workman's Comp) using this yeast was 10.7% and it was one of my most popular beers to date. OG must have been in the 1.1 range for sure, but again my notes are at the pub. Kicked a lot of peoples asses because it was so sneaky!! No off flavors

[Yeast]

Here's a little something I found today. It's interesting about half of it being good since Acetaldehyde is usually so related to fermentation of higher abv beers.

no one really pitches their high gravity beers at 1,500,000 though I would still use 750,000-1,000,000 and just increase oxygenation, remember o2 is harder to dissolve in higher gravity beers. and also maybe use yeast supplement for the Zn. Those are at least proactive solutions.

My guess is that yeast in the high stress alcohol environment and then with exposure to o2 decided to turn ethanol into acetaldehyde, since there's no vinegar I would doubt it's acetobacter causing it. that would explain why it's only in half of the beer. I think yeast will reverse ADH2 in stress with O2 usually they're stressed but don't have the O2.

I'm still surprised there isn't oxidation taste present though if that's the case. beats me for now.

[dick murton]

The yeast takes up the oxygen before it has a chance to react with the residual lipids. In my experience of 20 years brewing / packaging QA of beers of 11% or thereabouts, they tend not to produce the papery / cardboard flavours of T2N, even when filtered and then packaged in bottles without any fobbing system, but just go on to produce vinous flavours after a few months / years. I am guessing that the reason must be lack of lipids in the high gravity wort as the wort runoff was stopped at, from memory about 25 PG, and the relatively high levels of reducing compounds from the darker malts used.

[Lallemand Caroline]

Hi Matt,
My name is Caroline and I am the East Coast Rep for Lallemand Brewing Yeast. I had not seen this thread previously when reading through, and would love to hear what you have learned, or discussed in further detail since posting. I hope to provide you with some insight as well.
Cheers,
Caroline Parnin
Lallemand Brewing
Siebel Institute
cparnin@lallemand.com

[Yeast]

Plates

Both samples had 0 counts on BMB and UBA after 7 days anaerobic. Considering there was no sample port to get an aseptic sample taken there was no counts attributable to sampling itself either with that wine theif.

The wild yeast plate had colonies, to be expected, Saccharomyces Diastaticus and Saccharomyces delbrukeii both grow, your yeast is likely a diastaticus like 3711 for example

[mmmatt]

Hi Matt,
My name is Caroline and I am the East Coast Rep for Lallemand Brewing Yeast. I had not seen this thread previously when reading through, and would love to hear what you have learned, or discussed in further detail since posting. I hope to provide you with some insight as well.
Cheers,
Caroline Parnin
Lallemand Brewing
Siebel Institute
cparnin@lallemand.com

Hey Caroline. Yeast is the QC guy at Milwaukee Brewing and was generous enough to plate samples of both the affected and unaffected samples and as he stated both came back clean except for some wild yeast he believes to be part of your Belle Saison blend. When we were taking the samples, the off flavor was less than when it was when I first noted it so maybe it is aging away a little bit. I'm going to be getting this beer into the brite this week, but probably wont blend the two portions. I have used this yeast may times and have noticed that the beers I build with it change over time, or seem to. One of the things I like about it!

[Yeast]

This is what grew through on lin's wild yeast media. Small colonies same behavior as 3711 same size too. I'm guessing it's the yeast you pitched not actually wild (infection)

[porter]

Autolysis?

Is it possible that the yeast just died and there was Acetaldehyde (among other stuff) in the cells that was released into the beer? (although this sounds kind of implausible)

We have had late ferment Acetaldehyde issues that we attribute to yeast health and while it's happened in higher ABV beers, it's not directly attributable to high gravity worts. Oddly enough, when two beers are pitched from the same slurry, one can develop this problem while the other is perfect...

But our Acetaldehyde problem doesn't smell like green apple. It's more like a sweet lacquer aroma. We can have a beautiful beer in the first 4-5 days and then develop the off flavor quickly- actually it's worse in the aroma than flavor. Also, when cropping an off beer, we notice that the yeast slurry smells off- often of autolysis- and under the scope the viability is low and the cell walls are kind of wavy looking. If we don't crop the yeast from the cone, the off aroma intensifies.

I'm not sure if it's the same problem BUT, this happened to us in a barley wine that was destined for bourbon barrels and 4 months later, the Acetaldehyde was completely gone. So it might age out. I would get the beer off the yeast asap no matter what beer you're making. Cones don't make yeast happy.

[MJMurphy]

One way i have seen late-arrival acetaldehyde develop is through binding with sulfur during fermentation. The acetaldehyde is then released later when oxygen attacks the resulting compound. It usually would happen in package, but if O2 was allowed into the fermenter, that may be a possible source.

I don't have the reference for the exact mechanisms for it off-hand, but have experienced it.

Matthew