Bottle conditioning - carbed but has green apple off-flavor?

[Deckers_Beers]

I have a fully-carbed pale that I bottled about 1.5 months ago, & the green apple taste is pretty strong, to the point that it's almost cider-y on the end. It fermented for a full 3 weeks, had a stable FG of ~1.010 for a week, & my sample at bottling time tasted amazing, so the green apple isn't due to young beer or an infection prior to bottling. I also have a pretty anal cleaning/sanitation regimen, so I'm not thinking it was an infection during the bottling process, either.

There are 2 variables that I think may have contributed:

1. My yield was only ~4 gallons, but I used almost a full whirlfloc tablet in the BK. Could the yeast in the bottle have fallen out of suspension too quickly, carbing but not cleaning that up?

2. I ran out of corn sugar & used a small amount of granulated sugar from the pantry to make up the difference. Not sure if this would even be a factor, but it is a deviation from my norm.

I just roused the yeast in the bottles I haven't put in the fridge yet & put them in a warmer area, so I'll try another bottle in a few days. Anyone experience anything like this before? Thanks in advance for the help!

 

[Deckers_Beers]

I've been asking around with other homebrewers I know, & no one has seen this happen before...

 

[popsicleian]

What temp have the bottles been sitting at during the carbonating period? I think putting them in a warmer area is probably your best bet at this point.

 

[Deckers_Beers]

They sat around 58* for a day until I realized how cold it was there, & then put moved them into the house, so they were sitting around 65*, maybe a touch lower.

I did move them right near the heater vent & put a thermometer in there, so right now they're sitting just under 70*.

 

[popsicleian]

65 may have been a bit too cool for them to clean up, depending on what yeast strain you were using. Still, I would have expected them to finish that process in 1.5 months even at that temperature. Did you use gelatin or cold crash before bottling? I've only experienced long bottle conditioning times when I've done an extended cold crash or fined with gelatin.

I think rousing and moving to a warmer area is a good move, but I would wait more than a few days before you try another. Give them a couple of weeks--If they haven't cleaned up the acetaldehyde in 1.5 months, the yeast are probably pretty sleepy.

 

[Deckers_Beers]

65 may have been a bit too cool for them to clean up, depending on what yeast strain you were using. Still, I would have expected them to finish that process in 1.5 months even at that temperature. Did you use gelatin or cold crash before bottling? I've only experienced long bottle conditioning times when I've done an extended cold crash or fined with gelatin.

I used Safale-05, but no cold crash or gelatin before bottling, just the whirfloc in the BK.

I used more than a half tab of whirfloc in ~4 gallons, so I did consider that maybe too much of the yeast fell out before bottling... But then they wouldn't be fully carbed, right?

 

[popsicleian]

The Whirlfloc doesn't have any impact on the yeast--assuming you used it during the boil it just encourages proteins in the wort to settle out.

 

[Deckers_Beers]

The Whirlfloc doesn't have any impact on the yeast--assuming you used it during the boil it just encourages proteins in the wort to settle out.

Ah, didn't know that! I thought it clumped up anything that would be in the wort, proteins, trub, & yeast alike.

 

[joegbeer]

Green apple taste generally implies that either not enough yeast was pitched, or the yeast was not healthy.

The other factor could be taking the beer in primary off the yeast before giving it time to cleanup. Given 3 weeks in primary and a stable final gravity for a week, I don't think this is the situation here.

Fermentation temperature not bottle carbing temperature could be another variable.

 

[Deckers_Beers]

Green apple taste generally implies that either not enough yeast was pitched, or the yeast was not healthy.

The other factor could be taking the beer in primary off the yeast before giving it time to cleanup. Given 3 weeks in primary and a stable final gravity for a week, I don't think this is the situation here.

Fermentation temperature not bottle carbing temperature could be another variable.

The ferm temp was around 66*, then raised to 70* for the last week. I also used an entire dry yeast packet, & re-hydrated, so I don't think the pitch was unhealthy.

Although when I pitched on brewday, wort was closer to 58*-60* (cold day), & I had to raise the temp with my carboy heater. Since I had a healthy fermentation & it was tasting great throughout, I didn't think this had affected anything. Maybe it did???

 

[Herksey]

Going to bump this post because I have the same problem every now and then. Also want to give my input.

My beers have quite often very distinct green apple/acetaldehyde taste and nose after 1-3 weeks of bottling, then it has faded away. I think this has to do with underpitching or bottling too soon. The question is why does it always seem to come after the bottling? And my guess is probably stressed yeast and poor secondary fermentation. I use table sugar for bottling, but I doubt this is the issue. But it might be a part of it.

First time I encountered this was with US-05. Beer was bottled at day 6 (most likely too soon, yes I know) and probably underpitched (1 pack to 6 gallons of 1.058 OG). I don't have taste notes at bottling day unfortunately but 3 days after bottling (day 9) I have a clear acetaldehyde which has faded away at day 13. Fermentation temp was on the higher side with this beer.

The next beer was with Lallemand's Voss Kveik which I doubt was underpitched. Also they say this yeast doesn't really need to clean up and can withstand higher temperatures. So I was very confused off why this beer had the taste and for so long. The beer was bottled at day 6 with taste notes including fruity and clean. At day 10 it had huge acetaldehyde which faded away only after 10 weeks. Weirdest beer yet.

Then I had it with W34-70. Probably underpitch? 2 packs into 7 gallons with OG of 1.049. Primary for 2 weeks (maybe too little, one week around 15C/60F then room temp and lagered for 3 weeks with taste notes before bottling indicating no acetaldehyde. But again after bottling clearly acetaldehyde which then fades away after 3-4 weeks after bottling. I did a second beer and racked 6 gallons of 1.060 wort on the same yeast cake (overpitch?) and this beer had no acetaldehyde whatsoever before/after bottling.

Many brews pass with better practices and longer fermentation times.

But just now I brewed my newest lager with S-189, 8 gallons of 1.052 worth and 2 packs of yeast (23g). 3 weeks primary (first week fermentation temp around 13C (55F) and two weeks in room temp. Transition to secondary for lagering, no acetaldehyde. Bottling after 6 weeks in secondary, no acetaldehyde. 2 weeks after bottling, clear acetaldehyde.

The instructions on the S-189 pack says "one pack on 20-30 litres" (5-8 gallons) so you might think it's an overpitch but I really think it's too little comparing to the information on the internet (500g pack says 80g to 120g/hl and my batch translates to bit below 80g/hl). However, with the calculator Yeast Pitch Rate and Starter Calculator - Brewer's Friend it says I need as much as 6 packs of S-189.

 

[jmosterberg1]

I have just recently switched from 5 gallon propane burner brewing to 2.5 gallons on a Anvil Foundry. Of the 50 to 60 5 gallon brews previously I have never experienced this green apple phenomenon. However 3 out of my first 6 smaller brews had distinct green apple cider flavor. I am pitching full packs of rehydrated dry yeast just like I did for the 5 gallon batches, so I think my pitch rate should be OK. In the primary for 10 to 14 days to a stable FG. (1.010 last time). Keg and carb. I bought a smaller 3.25 gallon fermenter that won’t always shut air tight, and I get no airlock activity during fermentation. I was told by the LHBS it shouldn’t matter as CO2 given off at fermentation will keep the O2 out. Just dumped my last 2 batches, and am afraid to try a smaller brew again without some idea of what to do. Any data would be helpful.

 

[passedpawn]

In my experience, it was infection. I can trace the first troubles to a dirty beet (yes, you read that right) that I added to the boil pot as it was cooling.

For several batches, each which traced yeast or some other ingredient back to the beet beer, I had awful "green apple" flavor. It did NOT go away, even after years. I'll never wait it out again, what a stressful and disappointing occupation that is. dump and don't look back.

 

[jmosterberg1]

I tried waiting on the green apple batches…..warming them too. Just got worse, so they went in the drain. Saw another thread say that real hoppy beers like IPAs tend to oxidize very easily and make this green apple taste. All my dumped brews were IPAs. Yeasts were 04, 05, and Cellular Science Cali. I have confidence in my sanitation…….me thinks maybe it’s my fermenter.

 

[Beermeister32]

Sounds like acetylaldehyde. This information is from Stone Brewing’s website discusses acetylaldehyde reduction in brewing:

“For the next part of our guide to off-flavors we'll take a look at acetaldehyde, with persistance and consistency you can avoid this undesireable quality.

Acetaldehyde smells and tastes like green apples. Sometimes it’s described as “oxidized apples” or “acetic cider”.

How does it form in beer?

Acetaldehyde is the immediate precursor to ethanol in fermentation. Like diacetyl, acetaldehyde is found in large quantities during early fermentation as the yeast produces it en masse early in their metabolic cycle. If there is a high amount of dissolved oxygen present in the young beer, then the oxygen could react with ethanol and oxidize it back into acetaldehyde.

Acetaldehyde is also formed during too long sitting on the yeast. When yeast health is poor, cells can die and burst open (autolysis) which releases a lot of acetaldehyde into the beer. This is why it is important to stick to a strict yeast dumping regimen during aging, and avoid the heavy buildup of yeast in the cone of the fermentor.

How do you solve the problem?

Just like diacetyl, kraeusening is the best way to remove excess acetaldehyde. Brewers need to make sure that they aren’t removing the beer before fermentation has finished. Raising the fermentation temperature a few degrees (diacetyl rest) will help resolve acetaldehyde issues. The other cause of acetaldehyde is too much dissolved oxygen in the beer. Brewers need to make sure that oxygen inclusion is minimal during the brewing process and any cellar activities (i.e. dry hopping).”

 

[jmosterberg1]

Thanks for the data! After reading it thru I think I need to get a better airtight fermenter for my small batches, and try harder to eliminate oxygen contact during kegging. Gives me some solutions I can implement.