Recurring acetaldehyde problem with extract NEIPA brewed with S-04

[bw7hb]

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.

 

[thehaze]

Fermentis yeast do not require rehydration. I would also not oxygenate too much, as you would like some yeast esters in there, and oxygenation usually works against that. S-04 is a love or hate it yeast. Some love it, some don't, but it usually comes down to its ester profile and / or the tartness this yeast adds to the beer.

If it's diacetyl, then you need to step up your temperatures, as it seems the yeast is not cleaning properly after itself, although I have not experienced this myself when using S-04.

If it's a more vinegary/tart apple, then you have an infection and it seems you cannot get rid of. I can understand getting diacetyl once, but your schedule is OK, so that would not be a problem. My bet is an infection or maybe those carbonation drops are lending some kind of weird aroma/flavour to the beer.

 

[IslandLizard]

Could that off flavor come from the extract perhaps? Are you following their directions exactly?

Could it be your perception of the hop flavor/aroma? Mosaic, and Citra especially, aren't appreciated by everyone.

It could point to an infection lingering in your equipment, but it may well be the yeast. Not everyone likes S-04 either (I'm neutral toward it).
How about using a different yeast next time? What are your choices there?

Many of us use liquid yeasts such as WY1318, which has become my favorite for NEIPAs, it adds its own flavor which I think works well in that style.

Also, what kind of water do you use?
Do you make any mineral additions? They are an important part of that style.

 

[bw7hb]

Fermentis yeast do not require rehydration. I would also not oxygenate too much, as you would like some yeast esters in there, and oxygenation usually works against that. S-04 is a love or hate it yeast. Some love it, some don't, but it usually comes down to its ester profile and / or the tartness this yeast adds to the beer.

If it's diacetyl, then you need to step up your temperatures, as it seems the yeast is not cleaning properly after itself, although I have not experienced this myself when using S-04.

If it's a more vinegary/tart apple, then you have an infection and it seems you cannot get rid of. I can understand getting diacetyl once, but your schedule is OK, so that would not be a problem. My bet is an infection or maybe those carbonation drops are lending some kind of weird aroma/flavour to the beer.

Thanks for the suggestions. I'm pretty sure it's acetaldehyde as it matches the "green apple" flavor description.

Can acetaldehyde come from an infection or only from incomplete fermentation?

Another thought I had was that I could be under-pitching the yeast. Maybe I could try using two 11.5g packs next time?

I can rule out the carbonation drops as the taste is present before bottling.

 

[bw7hb]

Could that off flavor come from the extract perhaps? Are you following their directions exactly?

Could it be your perception of the hop flavor/aroma? Mosaic, and Citra especially, aren't appreciated by everyone.

It could point to an infection lingering in your equipment, but it may well be the yeast. Not everyone likes S-04 either (I'm neutral toward it).
How about using a different yeast next time? What are your choices there?

Many of us use liquid yeasts such as WY1318, which has become my favorite for NEIPAs, it adds its own flavor which I think works well in that style.

Also, what kind of water do you use?
Do you make any mineral additions? They are an important part of that style.

I don't think the flavor is from the extract as I used that hopped pale ale for my first beer and that was fine. Could be the wheat I guess but I doubt it.

I doubt it's my perception of the hops. I've had a few commercial beers of similar style and loved the strong hop flavors. The taste I'm getting is really bad and strong and doesn't taste like hops at all.

I could switch yeast but I think I want to try other options first.

I've tried both tap and RO water with no mineral additions and didn't notice any difference - I thought the water profile wasn't important with extract brewing?

 

[thehaze]

For 5-6 gal of beer with an OG of 1.050-1.060, 1 pack of yeast will suffice. But you can definitely try two packs next time.

If it's only present when using S-04, you might not like this yeast. Have you tried other yeast? BRY-97 from Lallemand is good for many styles and would work for NEIPA as well, seeing that Bissell Brothers from the US use that ( most likely the liquid equivalent ) and make great beer. Nottingham is a beast, although it wont make NEIPAs I think, but for anything else, will work great.

 

[IslandLizard]

Maybe I could try using two 11.5g packs next time?

A 5 gallon batch of 1.048 beer certainly does not need 2 11.5g sachets of yeast. 1 is plenty.

I thought the water profile wasn't important with extract brewing?

Water and mineral content is not as important, but for a NEIPA to shine you need enough Chloride and Sulfate, and at a ratio of around 2:1-3:1, preferably.

As you said, maybe it's the wheat LME that causes the off flavor, since that's something you haven't used before. Wheat has a distinct flavor/aroma, but it isn't anything like acetaldehyde or green apples.

The other thing is, aside from the pre-hopped liquid extract, you don't have any boil or whirlpool hops in your beer. Only dry hops. Maybe that's part of the flavor issue.

2 main causes of Acetaldehyde in beer:

• Acetobacter contamination: Acetaldehyde is produced by acetobacter as a precursor to acetic acid. This can make the beer taste more cidery/tart, like bruised apples.
  
  
• Oxidation of ethanol: if the beer is exposed to oxygen, this can reverse the reduction and turn the ethanol back into acetaldehyde.
  

Any fruit flies there?
Using secondaries?

 

[mediant]

Acetaldehyde may form as a result of yeast stress during fermentation, exposure to air or acetic bacteria.
If the problem is with the fermentation itself, it's because the yeast may settle prematurely before cleaning the acetaldehyde or its acetaldehyde metabolism is impaired, the reasons for that may include: over-pitching, over-oxygenation, loss of temperature control.
Otherwise exposure to air during dry-hopping is another common cause of acetaldehyde, as is bacterial contamination.

 

[bw7hb]

The other thing is, aside from the pre-hopped liquid extract, you don't have any boil or whirlpool hops in your beer. Only dry hops. Maybe that's part of the flavor issue.

The pale ale extract is hopped so I guess that's my "boil" hops as it would have been added during the boil.

Any fruit flies there?
Using secondaries?

No fruit flies that I know of. I'm siphoning the beer to a secondary bucket for bottling only because the trub/hop pile at the bottom of the primary is so high that it covers the tap hole.

I'm starting to wonder if it is an infection that I've had three times in a row. I think I should try a fairly different and simple recipe to try narrow the issue down.

 

[IslandLizard]

The pale ale extract is hopped so I guess that's my "boil" hops as it would have been added during the boil.

Are you actually boiling this or just adding it to hot or boiling water? Hopped extracts should not be boiled from what I understand.

You said you use Starsan for sanitation. What do you use to clean your equipment?

 

[bw7hb]

Are you actually boiling this or just adding it to hot or boiling water? Hopped extracts should not be boiled from what I understand.

You said you use Starsan for sanitation. What do you use to clean your equipment?

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.

 

[bw7hb]

If it's only present when using S-04, you might not like this yeast. Have you tried other yeast? BRY-97 from Lallemand is good for many styles and would work for NEIPA as well, seeing that Bissell Brothers from the US use that ( most likely the liquid equivalent ) and make great beer. Nottingham is a beast, although it wont make NEIPAs I think, but for anything else, will work great.

I have only used S-04 and some unlabeled yeast that came with a kit so I don't have much to compare with. But I'm very sure that if anyone tasted the beer they would say there's something seriously off with the flavor. I can't imagine this flavor being "normal" for any yeast. It's very strong and completely overwhelms any other flavors; I can't taste any malty or hoppy flavors at all.

 

[fuhmon]

If it is infection try using a NEW fermentation vessel. It’s normal for brew buckets to still smell hoppy after cleaning especially after IPAs. It’s also possible with a starting gravity of 1.048 a single sachet of yeast could be over pitching but really should be fine. If your fermentation temperature is consistent and not dropping for the first few days you also shouldn’t have any early flocculation issues preventing normal yeast metabolism of acetyldehide. Good luck!

 

[bw7hb]

I think I'm going to try a recipe with no wheat and no dry hopping but still using S-04. Maybe the dry hops are confusing the flavor a bit and it might be easier to diagnose without them.

 

[IslandLizard]

If it is infection try using a NEW fermentation vessel. It’s normal for brew buckets to still smell hoppy after cleaning especially after IPAs. It’s also possible with a starting gravity of 1.048 a single sachet of yeast could be over pitching but really should be fine. If your fermentation temperature is consistent and not dropping for the first few days you also shouldn’t have any early flocculation issues preventing normal yeast metabolism of acetyldehide. Good luck!

I think that using a new vessel is indeed a good idea. Just in case it is an 'embedded' infection.
What kind of fermenter are you using now?

There's cleaning and there's cleaning.
Just soaking something in 'Oxiclean' may not be enough to really clean it.

I use a stiff, non-scratching nylon hand brush inside my buckets to remove the krausen ring mostly, but the rest gets a scrub too. My go to cleaner is homemade PBW, the metasilicate (or TSP) component adds a lot of power to the cleaning action. But I also routinely use common Washing Soda, which is Oxiclean without the peroxide/O2 (which is highly overrated, IMO). Then a good rinse out perhaps another cleaning with fresh cleaner and another rinse. A good mopping with Starsan using a small washcloth sanitizes everything.

Pay special attention to the lid and those areas, airlock hole/grommet, the groove, threads, etc.
And your transfer tubing!
Basically use good sanitation on anything that touches your chilled wort (<150F/65C) and all your beer.

And... You can't sanitize something that isn't already clean in the first place! For example, you can't sanitize dirt.

The more I think about it, maybe you're indeed dealing with an infection. They just don't manifest themselves solely as an off flavor, there are usually other symptoms that go along with it, like sourness, pellicles, etc.

 

[Jag75]

I need to get a rig set up for carboy cleaning . I usually use pbw and let it sit for an hour . I hold my hand over the top and shake back n forth. I seen those rods with the cleaner on the end that you use for a drill but they want like 30$ . So I figured a paint mixing rod with a Terry cloth tied to the end . I use a fast fermenter usually but every so often I use a carboy .

If theres an infection in a fermenter can you soak with hot bleach water to kill it ?

 

[Cavpilot2000]

Aside from the acetaldehyde, which I got too, the one time I used S-04, I got a bubblegum flavor.
The beer ended up being a dumper and haven't used S-04 again.
YMMV.

 

[IslandLizard]

I need to get a rig set up for carboy cleaning . I usually use pbw and let it sit for an hour . I hold my hand over the top and shake back n forth. I seen those rods with the cleaner on the end that you use for a drill but they want like 30$ . So I figured a paint mixing rod with a Terry cloth tied to the end . I use a fast fermenter usually but every so often I use a carboy .

If theres an infection in a fermenter can you soak with hot bleach water to kill it ?

Why don't you stick a rubber bung in it? Then push against that as you shake.
Glass carboy? I think you got to be really careful with that spin cleaner or a paint mixer rod on a drill inside that narrow neck. The (uneven) mass from the wet felt/cloth on the bottom may cause it to wobble badly and ...

Yes, (Chlorine based) bleach is the preferred infection killer, but should not be used on Stainless.
I guess the OP can try that first.

 

[Jag75]

It's a plastic carboy . I did use a bung the first time but it fell in and was a booger to get out .

 

[IslandLizard]

It's a plastic carboy . I did use a bung the first time but it fell in and was a booger to get out .

I would not use a mechanical tool like that on plastic. No-no.
Plastic carboys should not be abraded! After a rinse, soak and rinse, use some warm water, some Oxi, and throw a washcloth in for a little friction. Swirling that should get them clean, and remove leftover stubborn patches.

 

[Jag75]

I would not use a mechanical tool like that on plastic. No-no.
Plastic carboys should not be abraded! After a rinse, soak and rinse, use some warm water, some Oxi, and throw a washcloth in for a little friction. Swirling that should get them clean, and remove leftover stubborn patches.

Thanks for that . I'll just put a clean cloth inside and shake . I'll scrap the idea of a mechanical tool .

 

[Dgallo]

As stated previously, acetaldehyde is a precursor to alcohol. Most fermentation will produce it in the beginning, but it should be reconsummed by the yeast and properly converted. Yeast stress, specifically underpitching and improper temps will cause this to happen to a greater extend. Also taking it off the yeast cake and transferring to a secondary is where most go wrong. After hitting your fg, you should always give your beers 3 days at 70-72*f so that the yeast can clean up any remaining acetaldehyde or VDK.

Since it’s a NEIPA, your off flavor could be contributed to oxidation. This style is notorious for oxidizing, which will be seen through a darkening of color towards copper and breakdown of bright hop flavors to a vegetable/cider flavor. Below is a picture of a beer not oxidized and one that is.

Good color

Oxidized

 

[IslandLizard]

Thanks for that . I'll just put a clean cloth inside and shake . I'll scrap the idea of a mechanical tool .

Oh, it's still mechanical. It's called the 'Jag Cleaning Station Mk II'!

 

[IslandLizard]

Just thought of something else.

How are those hops that come with the kits packaged? Any harvest year on them?

 

[BitterSweetBrews]

Following are some things I put together when I was studying for my Beer Judge Certification regarding Acetaldehyde:

Off Flavor - Acetaldehyde
Green apples, Grassy, can taste and smell acetic (vinegar/cidery)

Describe/Discuss Ever Appropriate? Yes at low levels
If so, what styles? Kellerbier, L/S/P American Lagers (from yeast character - optional)

How is it caused? How can it avoided/controlled:
Premature removal from yeast - Good yeast strain
Premature flocculation - Allow ferment to complete
Oxygen depletion- Aerate wort prepitching
Bacterial spoilage - Practice good sanitation
Oxidation - Practice good beer handling to avoid O2 contact
Long lagering will reduce

 

[bw7hb]

What kind of fermenter are you using now?

Just the typical plastic fermenter with a screw-on lid.

Just thought of something else.

How are those hops that come with the kits packaged? Any harvest year on them?

It's not actually a pre-packaged kit - just a bunch of ingredients which I get from the store. The hops are packaged in 100g vacuum packed packages, no harvest year information. The hops smelt pretty good when I opened them if that means anything.

What I'm going to do is brew a batch with two of the pale ale extracts (instead of pale ale + wheat) and no dry hops. If that works I'll add some dry hops on the next batch. Then if that works I'll add the wheat to the following batch. Maybe it is just an infection and now that I know to pay more attention to cleaning it won't happen again... anyway time will tell

 

[bw7hb]

Aside from the acetaldehyde, which I got too, the one time I used S-04, I got a bubblegum flavor.
The beer ended up being a dumper and haven't used S-04 again.
YMMV.

How bad was the acetaldehyde? Like undrinkable?

Yes, (Chlorine based) bleach is the preferred infection killer, but should not be used on Stainless.
I guess the OP can try that first.

Will bleach do something that starsan can't? Also I thought that bleach could leave some bad flavors in a fermenter?

 

[IslandLizard]

Will bleach do something that starsan can't? Also I thought that bleach could leave some bad flavors in a fermenter?

Yes, bleach kills pretty much anything alive. So does Iodine, which is often used as sanitizer (Iodophor, Povidone-Iodine). It's not as convenient to use as Starsan and stains plastic (and hands).

As long as you rinse out your bleach bombed vessels well, they should be fine to use. You may give them a wash with some washing soda (or Oxi). If they still smell of chlorine (they shouldn't) let air out for a couple days.

Instead of chlorine you can put them out in the bright sunlight for a day (or 2), UV kills microorganisms too.

 

[IslandLizard]

What I'm going to do is brew a batch with two of the pale ale extracts (instead of pale ale + wheat) and no dry hops.

Or only a half batch of Pale Ale, as a test?

 

[Cavpilot2000]

How bad was the acetaldehyde? Like undrinkable?


Will bleach do something that starsan can't? Also I thought that bleach could leave some bad flavors in a fermenter?

Not undrinkable, but not up to my standards. I kept trying to drink it, and even added keg dryhops to cover it up, but it never got better than "drinkable, but not enjoyable".

 

[IslandLizard]

Aside from the acetaldehyde, which I got too, the one time I used S-04, I got a bubblegum flavor.
The beer ended up being a dumper and haven't used S-04 again.
YMMV.

I've only used S-04 once, double pitch, in a 1.092-some Old Ale (that stalled at 1.032). I didn't detect any flaws except for the sweetness due to high FG.

We tasted all our efforts before we filled the rum pickled barrel with the 10-11 kegs. We all had used the same recipe (from BCS), same ingredients, and S-04. There were small, notable differences, but found no off flavors in any of them, although some were a bit 'soapy' and one or two were at 1.012-1.014.

 

[bw7hb]

Or only a half batch of Pale Ale, as a test?

Good idea, I'll do that and just pitch half a pack of yeast.

 

[Dgallo]

Good idea, I'll do that and just pitch half a pack of yeast.

Do a full pitch. Since you’ve already been having trouble with not getting a clean fermentation, bump the cell count.

 

[bw7hb]

Do a full pitch. Since you’ve already been having trouble with not getting a clean fermentation, bump the cell count.

Yeah I could, although I'd rather not change too many variables at once. I'm already going to be removing dry hops, removing wheat, and cleaning the fermenter more rigorously. I think that's probably enough changes for the next test batch without changing the pitch rate too.

 

[Dgallo]

Yeah I could, although I'd rather not change too many variables at once. I'm already going to be removing dry hops, removing wheat, and cleaning the fermenter more rigorously. I think that's probably enough changes for the next test batch without changing the pitch rate too.

Well acetaldehyde is typically a yeast/fermentation issue but can also be an oxidation issue. Its formed when yeast do not properly convert sugar to alcohol and when the polyphenols in the hops get oxidized. The more healthy yeast pitched the less likely you are to get it through fermentation. If I’m you I’m starting with fermentation. Overpitch your beer and keep everything else the same. This way you can insure a healthy fermentation. If you still detect it after that, then that means you need to tighten up your post fermentation practices to limit oxidation. Better racking with less splashing. You also may want to look into kegging if your going to continue to brew NEIPA.

Side not about eliminating your dryhop. instead of cutting it out completely, you could put them in on the 3 day of fermentation. That way the yeast will consume any of the oxygen that wort and force out any oxygen in the headspace. Just a thought. Good luck. I use to have the same problem but after getting some solid advise from Justin from Sloop Brewing Co and upgrading to kegging, I haven’t encountered it again.

 

[IslandLizard]

Well acetaldehyde is typically a yeast/fermentation issue but can also be an oxidation issue. Its formed when yeast do not properly convert sugar to alcohol and when the polyphenols in the hops get oxidized.

So oxidation could well be the case here.

 

[Dgallo]

So oxidation could well be the case here.

This is a small great read explaining the formation of acetaldehyde and how it impacts a beer. Author did a great job pulling out the main points through a very simple explanation.
https://www.google.com/amp/s/beerandbrewing.com/amp/off-flavor-of-the-week-acetaldehyde

 

[IslandLizard]

This is a small great read explaining the formation of acetaldehyde and how it impacts a beer. Author did a great job pulling out the main points through a very simple explanation.
https://www.google.com/amp/s/beerandbrewing.com/amp/off-flavor-of-the-week-acetaldehyde

Yes, it's a good, clear and concise explanation of the origin of the flaw and ways to prevent it.

The only thing I don't agree with is the bolded part of this phrase (bolding is mine):

So stay patient, and wait a few days after reaching terminal gravity before you rack that beer to secondary.

I realize the writeup is 2 years old. But 'secondary,' really? The use of secondaries in 'regular brews' has been debunked for much longer already.

Oxidation due to the dry hopping can indeed be the cause here. The OP dry hopped on day 10 after pitching, so fermentation has definitely completed, and is in her final stages of the conditioning phase, and started to or has already flocced out. There's nothing to take up newly introduced oxygen.

Without having a way to prevent or severely limit oxygen exposure when dry hopping, moving the dry hop up to the time when active fermentation is still ongoing is a good remedy.
In NEIPAs I always add dry hops at 50-40% and 10% of remaining attenuation. And those are all added under CO2, or followed by several headspace flushes/purges. I use 6.5 gallon buckets, lids are pretty air tight.

Kegging is surely recommended for hoppy beers, especially NEIPAs. I can only see them suffer more from the bottling/bottle carbonation process, although that is not the cause of the acetaldehyde here, it's there already before bottling.

 

[Dgallo]

Good point. I didn’t even pay attention to that portion. Yeah no secondaries. But idea can still be put into place with kegging or bottling, remember to give your beer time to clean up after hitting fg. I dryhop undepressure and coldcrash while connected to my co2. Greatly minimizes my chances for oxidation

 

[bleme]

You could also try taking your beer to a local homebrew club. Words are a poor substitute for actually tasting, so an experienced brewer might be able to pick out the problem right away.
https://www.newzealandbrewer.co.nz/find-a-club/