Recurring acetaldehyde problem with extract NEIPA brewed with S-04

[bw7hb]

Interesting podcast on dry hop creep: http://masterbrewerspodcast.com/098-dry-hop-creep

 

[IslandLizard]

I already removed the settled-out yeast from the collection bottle before I dry hopped, as I dry hopped via the collection bottle.
Hopefully there will be enough in suspension.

I think I'll try leaving it for a few days and if nothing changes I could de-pressurise it and add yeast through the lid and just purge with CO2 after.

If I were to add more yeast should I use the same strain, also how much?

Ah, I see. Hope you're lucky and there's still enough left to do the job. Keep rousing, yeast on the bottom isn't doing any work.

Yup, purge the headspace after opening the keg. Or stream CO2 in while removing the lid and adding the yeast starter counterstream. Work fast. But the opening is large, so a few purges afterward will remove most of any O2 that entered.

I would make a 1 liter "vitality' starter from the dry yeast and pitch that at high krausen. It's difficult for yeast to establish itself in an alcohol rich environment with no (easy) fermentables. Perhaps add a little extra sugar along with it. The beer should be at 72-74F so she's ready to get her extra D-rest. You can use any yeast, a medium flocculator would be best IMO, so she doesn't crash out too soon. Give it a few days then taste.

 

[bw7hb]

I left it a few days without adding yeast and it didn't seem to clean up, so I pitched the starter.

4 days later it seems to have fixed the diacetyl but the beer still doesn't smell entirely right. Might just be because it's warm - I'm going to chill it for a few days then try it.

 

[mediant]

What was the cold crash temperature? Do a diacetyl test first before cooling the beer again below 15C, it's very simple and only takes half an hour. In general, you are not supposed to smell the diacetyl at any point during fermentation or maturation, as warm D-rest is not for the yeast. It's to encourage decarboxylation of diacetyl precursor acetolactate.

 

[Soulshine2]

I'm trying to brew a NEIPA but I'm having issues with very strong acetaldehyde / green apple off flavor at bottling time and after a month of bottle conditioning. As I'm fairly new to home brewing I'm using all extract.

The first beer I ever brewed was a pale ale and it worked out very well. I simply used the unlabeled yeast that came with the hopped LME, added some unhopped LME, fermented for seven days then bottled. The beer was clean tasting and just "tasted like beer" after two weeks of bottle conditioning.

Since then I've done three attempts at this NEIPA recipe with various changes to each iteration to try fix what I thought was wrong with the previous batch. Despite these changes all of them have the green apple, almost cidery, off flavor mentioned above. It does seem to die off a bit after a month in the bottle but is still quite strong and by then the beer is looking pretty oxidized and the hop aroma is probably gone anyway.

I bottled the third attempt last night - it has the same taste and it seems just as strong as previous batches despite making some decent process improvements to this batch. I realize it hasn't had a chance to bottle condition yet, but based on the previous batches still having the taste after 3-4 weeks, I don't have high hopes for it.

Some of the things I've done to try fix this are listed below:

• Re-hydrated the yeast before pitching.
• Oxygenated the wort the best I could by shaking it around for a few minutes before pitching.
• Kept the wort at 18°C for first 3 days of fermentation and slowly increased it to 21°C over the next few days.
• Left it in the primary for 13 days (as opposed to the 7-9 days I did for the first batch) before cold crashing.
• Dry hopped only once at day 10 of fermentation instead of twice to try and avoid oxygen contact.

All of the brews have had an OG of 1.048 and FG of 1.014. I'm using starsan and I'm pretty confident with my sanitation practices. I use carbonation drops instead of priming sugar.

I'm starting to wonder if S-04 is just a bad yeast. Or maybe I need to leave it in the primary for even longer? But from what I've read S-04 should be a pretty fast yeast to finish and clean up.

Any thoughts on this would be much appreciated.

I always wonder to myself about the whole NEIPA thing everyone goes to,especially beginners. Not saying its wrong, Im just not into them at all.
But besides that what I AM into that ive found since adopting its procedure has turned out some good beer ,better than not doing it anyway, is kraeusening with saved sterile unfermented wort at bottling. Adds no sugars other than what you made the wort/beer with in the beginning. Hopped or not , your choice. No carbonation drops ,etc. In the end its just beer. I make 5 and 6 gallon batches so my addition is basically 1.2 qts . I add half to the bottling bucket before racking,so it gets thoroughly mixed , the rest goes in at the end, gently stirring to mix and mingle again and then bottle.
Other advice is same as given, S-04 is a love /hate yeast. I used it only once and cant say it made what I was looking for exactly.

 

[bw7hb]

I did a forced diacetyl test before chilling and couldn't detect any diacetyl.
I tasted a bit just now after it had been chilling for 24hr and now it tastes like it has acetaldehyde (also smelt like that prior to chilling).
I think I've probably been dealing with both diacetyl and acetaldehyde lol.

Probably going to dump this lot and start again.
Next time I'll sample the beer before dry hopping to ensure there are no off-flavors at that stage.
Also I think I'm going to dry hop at about 5C to prevent any yeast activity after dry hopping. It'll be staying in chilled kegs for the rest of it's life so why not

 

[bw7hb]

For the latest attempt I dry hopped with only 75g (half mosaic, half citra) at day 2 of fermentation and left it to finish off for another week. US-05 yeast. Fermentation seemed to go very well.
Same result, so obviously dry hop creep wasn't the issue.

It seems like the beer has about 3-4 off flavors. Acetaldehyde is the main one, then diacetyl, then astringency, then a slight metallic aroma.

I hate to say this but I'm going to give up on the NEIPA for now and do a few beers that aren't dry hopped, to try prove that it's not a sanitation issue or something.

 

[bw7hb]

Update six months later:

Since my last post I've attempted numerous beers, all of which have had very severe off flavours/aromas - mostly acetaldehyde but also with some other issues such as diacetyl and solvent-like off flavours. The beers were very simple with no dry hopping or anything fancy, mostly using US-05 yeast. I re-hydrated the yeast, aerated the wort, even tried yeast nutrient, to no avail. The fermentations didn't seem to be going very well as they all took at least 24 hours before I could see any signs of fermentation and took about 10-12 days to finish, leaving me with some disgusting apple juice beer.

I was one more attempt away from giving up on home brewing for ever, when I finally made a drinkable beer. The difference with this one was that I pitched twice as much yeast. Also I used a different yeast, the yeast that comes with Black Rock extract kits which I believe is S-33. There were signs of fermentation just 2 hours after pitching and it finished in 7 days, and NO GREEN APPLE BOMB!!!

My next beer will be using US-05 or S-04 and I'm going to pitch two packets and hopefully that clears this nonsense up for good.

 

[Dgallo]

Update six months later:

Since my last post I've attempted numerous beers, all of which have had very severe off flavours/aromas - mostly acetaldehyde but also with some other issues such as diacetyl and solvent-like off flavours. The beers were very simple with no dry hopping or anything fancy, mostly using US-05 yeast. I re-hydrated the yeast, aerated the wort, even tried yeast nutrient, to no avail. The fermentations didn't seem to be going very well as they all took at least 24 hours before I could see any signs of fermentation and took about 10-12 days to finish, leaving me with some disgusting apple juice beer.

I was one more attempt away from giving up on home brewing for ever, when I finally made a drinkable beer. The difference with this one was that I pitched twice as much yeast. Also I used a different yeast, the yeast that comes with Black Rock extract kits which I believe is S-33. There were signs of fermentation just 2 hours after pitching and it finished in 7 days, and NO GREEN APPLE BOMB!!!

My next beer will be using US-05 or S-04 and I'm going to pitch two packets and hopefully that clears this nonsense up for good.

Did you mention if you have temp control?

 

[kh54s10]

There is something else going on here unless all your beers have been very high gravity recipes. One pack should be good to about 1.070 without producing off flavors. I have done one pack in higher gravity beers than that with no off flavors (at least that I can detect).

 

[passedpawn]

Update six months later:

Since my last post I've attempted numerous beers, all of which have had very severe off flavours/aromas - mostly acetaldehyde but also with some other issues such as diacetyl and solvent-like off flavours. The beers were very simple with no dry hopping or anything fancy, mostly using US-05 yeast. I re-hydrated the yeast, aerated the wort, even tried yeast nutrient, to no avail. The fermentations didn't seem to be going very well as they all took at least 24 hours before I could see any signs of fermentation and took about 10-12 days to finish, leaving me with some disgusting apple juice beer.

I was one more attempt away from giving up on home brewing for ever, when I finally made a drinkable beer. The difference with this one was that I pitched twice as much yeast. Also I used a different yeast, the yeast that comes with Black Rock extract kits which I believe is S-33. There were signs of fermentation just 2 hours after pitching and it finished in 7 days, and NO GREEN APPLE BOMB!!!

My next beer will be using US-05 or S-04 and I'm going to pitch two packets and hopefully that clears this nonsense up for good.

Back when I started brewing, I had a couple of bouts of acetaldehyde. Man, when that awful green apple taste is there, it's totally undrinkable. Those went down the drain.

In my case, it was caused by a dirty beet that I sliced and added to one fermentor. I then used that yeast to make another beer. So my money's on infection.

Acetaldehyde is part of the normal yeast fermentation cycle, but it gets converted to alcohol immediately, assuming healthy yeast. So, if your yeast wasn't healthy, I suppose you could run into problems. In your case, it's highly unlikely that you've had so many bad batches of yeast. Dry yeast is very dependable. I've made a zillion beers with dry yeast, usually one packet per carboy, no problem. I don't oxygenate my wort, but I do usually rehydrate the yeast.

 

[bw7hb]

Did you mention if you have temp control?

Yes, I have decent temp control for all fermentations.

There is something else going on here unless all your beers have been very high gravity recipes. One pack should be good to about 1.070 without producing off flavors. I have done one pack in higher gravity beers than that with no off flavors (at least that I can detect).

All the beers have been around 1.050. I used to think I was getting an infection in the beer, however the seemingly sluggish fermentation is what led me to try pitching more yeast. I guess I should try US-05 or S-04 again with the increased pitch rate and see how that goes.

One other thing I did differently with this batch was sanitized the fermenter with boiling water (stainless fermenter) rather than starsan (still used starsan for other equipment). I wonder if there was some infection that was surviving starsan? But that still wouldn't explain the sluggish fermentation.

I'll report back after my next brew.

 

[kh54s10]

As I said previously, I believe something else is going on. US-05 has been described as sluggish. But mostly in how long it takes to get to FG. Even at 24+ hours lag time you should not be getting any off flavors. Pitching more yeast won't hurt, but at the gravity you quote you should not need more than one pack. I have made much higher gravity beers and used only one pack without any issues.

 

[Bobby_M]

Decent temp control can be interpreted a lot of ways. Do you have an active control system wuth a thermostat that will heat or cool the fermenter?

Post ferment temp crash happens normally and it stunts the yeast at the worst time; when they would otherwise clean up acytaldehyde and diacetyl. Actively warming even a couple degrees at that time makes a real difference. Double pitching yeast effected the same end, but there are beer flavor reasons why it wont always be the best way.

 

[bw7hb]

So I just took a sample of my latest attempt, in which I pitched two packets of US-05 into a 21 liter batch. Same **** different day. Hydrometer reading has reached target SG but it's a green apple bomb. I wouldn't even know it was supposed to be beer if I didn't know what it was, that's how bad it is. All I get on the nose is this intense apple-y aroma.

Signs of fermentation activity seemed to finish up a bit quicker than my previous attempts with US-05, probably because of the higher pitch rate, also I fermented this one a bit warmer. It's only been six days since pitch so I will probably leave it another week or so and see if it changes, but past batches haven't improved at all after two weeks so I'm not very hopeful.

Decent temp control can be interpreted a lot of ways. Do you have an active control system wuth a thermostat that will heat or cool the fermenter?

Yes I have a chest freezer / heat belt setup. Temperature probe is taped to side of fermenter with insulation on the outside. There's no way it's a temperature issue.

At this point I guess it has to be an infection, and maybe I just got lucky on my previous batch with S-33. I noticed S-33 kicks off fermentation a lot quicker than US-05 so maybe that helped ward off an infection?

 

[Dgallo]

So I just took a sample of my latest attempt, in which I pitched two packets of US-05 into a 21 liter batch. Same **** different day. Hydrometer reading has reached target SG but it's a green apple bomb. I wouldn't even know it was supposed to be beer if I didn't know what it was, that's how bad it is. All I get on the nose is this intense apple-y aroma.

Signs of fermentation activity seemed to finish up a bit quicker than my previous attempts with US-05, probably because of the higher pitch rate, also I fermented this one a bit warmer. It's only been six days since pitch so I will probably leave it another week or so and see if it changes, but past batches haven't improved at all after two weeks so I'm not very hopeful.


Yes I have a chest freezer / heat belt setup. Temperature probe is taped to side of fermenter with insulation on the outside. There's no way it's a temperature issue.

At this point I guess it has to be an infection, and maybe I just got lucky on my previous batch with S-33. I noticed S-33 kicks off fermentation a lot quicker than US-05 so maybe that helped ward off an infection?

If I’m you and the funds are available, I’m getting all new post boil equipment and fermenters just to be safe but acetaldehyde is almost always a fermentation or oxidation issue
https://www.google.com/amp/s/beerandbrewing.com/amp/off-flavor-of-the-week-acetaldehyde/

 

[bw7hb]

It's been sitting in the primary for 16 days now and I just took another sample. I noticed while taking the sample that the surface of the beer was very clean, no pellicles that would indicate infection, just a few small patches of bubbles. The gravity hasn't changed since 10 days ago, the green apple aroma is not quite as intense as it was, but now there's a strong white wine aroma.

I'm wondering if it's oxidized now. Sherry is a common description for oxidized beer, is it similar to white wine? (I've never tasted sherry). From what I can see it's like a sweeter version of white wine which would match the aroma of my beer pretty well.

As @Dgallo mentioned oxidation could also be the cause of the acetaldehyde, but I'm just at a loss as to how it could be so bad?

Interestingly, the previous batch (which didn't have this issue) was done in a pressure fermenter which would be a lot safer from oxidation issues. Perhaps my plastic fermenter has a small leak somewhere, or the lid isn't sealing properly. There can't be a massive hole as the airlock was bubbling during fermentation, but would oxygen ingress through a tiny hole / poor seal be enough to do this to a beer?

 

[kh54s10]

As @Dgallo mentioned oxidation could also be the cause of the acetaldehyde, but I'm just at a loss as to how it could be so bad?

Interestingly, the previous batch (which didn't have this issue) was done in a pressure fermenter which would be a lot safer from oxidation issues. Perhaps my plastic fermenter has a small leak somewhere, or the lid isn't sealing properly. There can't be a massive hole as the airlock was bubbling during fermentation, but would oxygen ingress through a tiny hole / poor seal be enough to do this to a beer?

I doubt a small pinhole could cause such a bad problem. There are tons of threads where people ask why their beer never fermented. Then when diagnosed, it turns out their worry was because they never say any activity in the airlock and the beer had in fact fully fermented. Just a leaky lid on a bucket. And those beers did not turn out an oxidized mess.

 

[Dgallo]

If you’re a somewhat experienced brewer( don’t take that any type of way, I don’t know you personal so I’m just stateibg generally) and under stand the need for a healthy fermentation and implemented that in your practices, and you don’t have the issue with any other beer style than NEIPAS or hoppy beer styles, I would almost guarantee to you that it’s an oxidation issue. Hoppy styles are notoriously susceptible to oxidation due to how easy the excess polyphenols from the hops oxidize. It can turn to apple cider/sherry wine sweetness and stale the hops completely. I ran into this issue for half a year until Justin from Sloop Brewing was kind enough to try a few of my beers and help me improve on my process. They all started out ok, then would get cider lik and drop in overall hop flavor/aroma.
A lot of ppl use 04 without an issue so it’s extremely hard for me to believe after multiple attempts with the same yeast (multiple different growth generations from the supplier) that it keeps happening. I would think it’s a process issue.

 

[Pennine]

what size fermenter are you using?

 

[bw7hb]

If you’re a somewhat experienced brewer( don’t take that any type of way, I don’t know you personal so I’m just stateibg generally) and under stand the need for a healthy fermentation and implemented that in your practices, and you don’t have the issue with any other beer style than NEIPAS or hoppy beer styles, I would almost guarantee to you that it’s an oxidation issue. Hoppy styles are notoriously susceptible to oxidation due to how easy the excess polyphenols from the hops oxidize. It can turn to apple cider/sherry wine sweetness and stale the hops completely. I ran into this issue for half a year until Justin from Sloop Brewing was kind enough to try a few of my beers and help me improve on my process. They all started out ok, then would get cider lik and drop in overall hop flavor/aroma.
A lot of ppl use 04 without an issue so it’s extremely hard for me to believe after multiple attempts with the same yeast (multiple different growth generations from the supplier) that it keeps happening. I would think it’s a process issue.

Well, I've done about 15 brews now, all extract brews, and only about 4 of them have been successful, the remaining ones with this acetaldehyde problem or similar. So I guess I'm somewhat "experienced" but obviously doing something fundamentally wrong still.

Regarding what you mention about hoppy beers - the last few attempts have had this acetaldehyde issue before any dry hops have been added (and there are none added before fermentation except for what's in the extract kits, which isn't much) so it's nothing to do hops. I've decided not to dry hop until fermentation is 100% complete, so I can make sure I'm not just wasting my hops by throwing them into apple juice. Also I think the hops have been confusing the off flavors in the past. I am using some wheat extract (about 1/4 of the total malt), maybe this is more susceptible to oxidation?

My current thought is that the acetaldehyde detected after a week in the primary was caused by a fermentation issue or infection, then the sherry aroma detected a week later on the second sample was caused by oxidation from when I took the lid off for the first sample. I think I'm going to leave it another week or so and see what happens to it, whether it gets worse etc.

Also I'm going to start a new batch using a completely different extract kit, in my stainless pressure fermenter (easier to clean and no chance of oxidation). Hopefully I can get a few decent batches under my belt and rule out some massive sanitation issue as the cause.

what size fermenter are you using?

It's a 21 liter beer and the fermenter I believe is around 25 liter total capacity. Fairly standard setup.

 

[kh54s10]

Sorry I didn't read your post properly; you already mentioned the pre-hopped extract. No I'm not boiling anything - just adding the extract to hot water.

I use sodium percarbonate to clean my equipment. I let it soak for about 48 hours then rinse with tap water. Tap water is fairly clean here in New Zealand.

I've noticed after cleaning that there is still a faint beer smell from the previous batch - should cleaning completely remove the smell or is this impossible? I think I need to step up my cleaning game as this is something I admittedly don't put a lot of effort into.

From the last post I went back to see what else there is.

1) Try sourcing a kit from somewhere different. Get one with extract, specialty grains and hops. One that requires a boil.
2) Try a different cleaner.
3) Try a different water source.
4) Try a different yeast.

Your failure rate says that it is either water or something else you are doing drastically wrong in your procedure. I haven't had as many failures in 8 years of brewing as you have in your short time. Acetaldehyde has been something I have never encountered.

 

[downzero]

I suspect your diagnosis of the problem is wrong. What kind of water did you use to produce these batches?

 

[bw7hb]

I suspect your diagnosis of the problem is wrong. What kind of water did you use to produce these batches?

I have tried both tap water and RO water with the same results.
The few successful beers I've done all used normal tap water.

Do you mean that I might be diagnosing the off-flavor incorrectly? Could be the case as I don't have a lot of experience.

A few months back I took samples of a few failed beers to two separate homebrew stores for advice, and they both said they thought it was probably an infection due to how bad it was. One of them wasn't able to indicate what the off-flavor was but they acknowledged it was quite strange, other one said "solvently / acetate + small amount of diacetyl". Both of those beers had significant amounts of dry hops added so I imagine that confused the flavor/aromas a bit. I agreed with the solvent off-flavor on that batch, wasn't really getting the acetaldehyde, maybe it wasn't there on that one or was just being masked by hops.

 

[Pennine]

I think you might have a diastaticus infection. I had one a while back and sounds pretty similar flavor wise. It seemed to have affected hoppy ales more so than non-hoppy ones so I also went down the hop creep path. If you bottle an easy test is to leave it warm for a couple weeks and if it gushes then you know. The fact that you used a different fermenter and it was fine is a good indicator.

 

[bw7hb]

I inspected the beer again today (19 days since pitching yeast), and noticed what might be some sort of pellicle.
I'm referring to the white-ish film not the collections of bubbles.
Does anyone know what this might be?

20200102_173512

• bw7hb
• Jan 1, 2020

Edit: I believe pellicles usually form when the beer is exposed to oxygen which may explain why it's just showing up now after taking samples (assuming that this is in fact an infection). I might open the lid for a bit each day to introduce more oxygen and encourage the pellicle to grow since this beer will probably be dumped anyway.

 

[passedpawn]

Look for large waxy bubbles forming, or web-like patterns in the film. Those are common semaphores used by the infective naval forces. Of course, if it grows, that's another obvious indicator.

Healthy wort often has light film like that. What you're seeing might just be insoluble materials from the grain or hops. I almost always have some of that after 2 weeks of fermenting.

 

[passedpawn]

Also, I never open my fermentor until fermentation is complete, usually 10 days (at which time I add gelatin and begin cold crash). Back in my early days of brewing I was opening and testing gravity all the time. I know now that I was adding a lot of unnecessary risk.

 

[bw7hb]

Latest batch turned out great

It was a "grapefruit IPA" extract kit with dry hops, using M44 yeast (which I believe is just repackaged BRY-97).
I used RO water and fermented at 20C for around two weeks before adding dry hops.
Fermentation was done in a stainless pressure fermenter, which was cleaned with sodium percarbonate and sanitized with both starsan and boiling water.

I noticed a bit of strange sweet aroma when I took a sample before dry hopping, but it seems to have faded a lot after cold conditioning and it tastes fine. Maybe something to do with the grapefruit flavoring added to the extract.

Once this batch has been consumed, I plan to try again with S-04 and US-05 and see what happens.

 

[Tobor_8thMan]

I inspected the beer again today (19 days since pitching yeast), and noticed what might be some sort of pellicle.
I'm referring to the white-ish film not the collections of bubbles.
Does anyone know what this might be?

20200102_173512

• bw7hb
• Jan 1, 2020

Edit: I believe pellicles usually form when the beer is exposed to oxygen which may explain why it's just showing up now after taking samples (assuming that this is in fact an infection). I might open the lid for a bit each day to introduce more oxygen and encourage the pellicle to grow since this beer will probably be dumped anyway.

I believe, based on the picture, these are simply lipids(fat) on the surface. IMO, don't worry as this is normal. Will see basically the same if one stirs baking yeast into warm water and allows it to sit (proof) for a few minutes.