Recurring acetaldehyde problem with extract NEIPA brewed with S-04

[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/

 

[bw7hb]

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.

Ok I think I'm going to do a half batch with just the pale ale extract, with a whole pack of yeast, and dry hopping once early on in fermentation. Then the test batch should still be fairly nice if it works

I've come across a method of dry hopping where you boil hops in plain water for about 10 minutes and add the liquid to your fermenter just before pitching yeast. Maybe that's a good option to avoid oxidization? Anyone have any experience with this method?

 

[Dgallo]

Ok I think I'm going to do a half batch with just the pale ale extract, with a whole pack of yeast, and dry hopping once early on in fermentation. Then the test batch should still be fairly nice if it works

I've come across a method of dry hopping where you boil hops in plain water for about 10 minutes and add the liquid to your fermenter just before pitching yeast. Maybe that's a good option to avoid oxidization? Anyone have any experience with this method?

That would be considered making a hop tea not deyhopping. Boiling it will cause you to isomerize your alphas and gain Ibus. Also you will boil off a portion of those precious oils you wanted to get into your beer by choosing to dryhop in the first place. Will it remove most of oxygen if not all? Sure, but if you really want to try something like that, you’d be better off boiling less than a cup of water to remove the dissolved oxygen. Then let it cool with out agitating so you don’t reabsorb Oxygen and the add the hops when your below 140 and let them break up without stirring(same reason, to not add oxygen) and then add to your beer without splashing.

All that being said id advise against it. I would just dryhop at the tail end of fermentation so that the yeast and co2 produced by the fermentation take care of the oxygen contact issue for you. Simpler for you and limits the potential for actually adding more oxygen if you’re not extremely careful.

 

[IslandLizard]

That!^
Yeah, forget about making hop teas, it's nothing like dry hopping nor an alternative.

Now, many of us homebrewers dry hop successfully after fermentation has completed, even after or concurrently with the yeast's 'conditioning phase'. Dry hopping 3-5 days prior to packaging is still the recommended process, except maybe for NEIPAs and other hop drenched beers. We rarely hear about acetaldehyde bombs.

I have the feeling there's something in your process that's more or less unique causing the problem.

 

[kh54s10]

I don't think it has anything to do with S-04, unless the OP just doesn't like the flavor imparted by the yeast. I use S-04 quite a bit and have never gotten acetaldehyde. In fact some of my best beers had S-04 as the yeast.

 

[couchsending]

Never brewed extract so I have no idea if what you’re experiencing might be slightly caused by that, but I doubt it.

You don’t need to oxygenate or aerate S04. You don’t need to rehydrate it either.

For 1.048 wort 1 pack is more than enough, two would be way too much and lead to other issues as well.

The temps you list those are controlled or ambient? How are you measuring the temps.

This is not caused by dry hopping after fermentation. I rarely dry hop during fermentation any more and never experience this issue. You can run into other off flavors by keeping hops in contact with lots of yeast at elevated fermentation temps.

The on my time I experience the dreaded green apple flavor was when using S04 and when fermentation has spiked. It can produce a lot of heat on its own and unless you have good temp control it can get elevated rather quickly. In my instance it did clean up eventually.

Very hoppy beers, regardless of what part of the US they originate from, are incredibly hard to make well as a home brewer especially if you’re bottling. Hop aroma and flavor is the first thing to go when the beer comes in contact with too much oxygen.

Try to make the same recipe with Us05. It’s a much more forgiving yeast. I would be willing to bet you won’t experience any acetaldehyde.

On another note Bry-97 is not the dry version of American Ale II or the anchor ale strain. It’s not really similar to any liquid yeast strain. However it does posses the genetics to be able to bio transform hop compounds.

 

[bw7hb]

The temps you list those are controlled or ambient? How are you measuring the temps.

I have a chest freezer with a temperature controller, the probe is against the side of fermenter with a bit of insulation. The insulation on the probe was probably a bit lacking but I had the temp set to 18C so I can't imagine the beer got higher than around 21C if it was a bit warmer inside the fermenter.

 

[couchsending]

I have a chest freezer with a temperature controller, the probe is against the side of fermenter with a bit of insulation. The insulation on the probe was probably a bit lacking but I had the temp set to 18C so I can't imagine the beer got higher than around 21C if it was a bit warmer inside the fermenter.

Yeah the issue with 04 is even over say 66f it can start to produce some really odd tart like flavors. It’s a rather unforgiving yeast honestly. If I was you I’d try the next batch with 05 before I did anything else differently. That is if you want to stick with dry yeast.

 

[bw7hb]

Ok well I just got the supplies and the LHBS was out of S-04 so I'm going with US-05

I think I'm going to pitch the whole packet in the half batch. According to https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator this is about right for the "Pro Brewer" setting - I have no idea which setting on here is "best" but I don't think I'm massively over pitching.

 

[couchsending]

Just be careful it’s easy to end up with Diacetyl when overpitching 05. Make sure you let it warm up over 21c for a few days after fermentation is over and gravity is stable.

 

[bw7hb]

Ok I've pitched the yeast and I'll ferment this one at 22C (it seems US-05 has a higher temperature range than S-04, 18-28C). I only pitched about 2/3 of the packet in the end.

I'll update y'all with how it goes...

Also I'm going to try get a kegging setup before this one's finished. I can't be bothered going through the bottling procedure any more...

 

[bw7hb]

Ok so fermentation never seemed to go off like it usually does, about half the amount of airlock activity and krausen as usual. I was getting worried then I realized that should be expected with a half size batch

I dry hopped yesterday and checked the gravity today (72 hours after pitching yeast) and the gravity is at 1.016 with virtually no airlock activity. The gravity sample smelt and tasted exactly like the previous batches - green apple. I suppose this is to be expected only 3 days into fermentation? Has anyone ever tasted their wort this early on with a US-05 beer, if so what did it taste like?

I'll do another gravity sample and taste in about 2-3 days and see if anything's changed. If not then I might stir up the yeast to try get them working again.

EDIT: I guess this kind of rules out oxidation as the issue - I doubt the beer would have had time to completely ferment into ethanol and oxidize back to acetaldehyde.

 

[deadwolfbones]

Can you get a different source of extract? Maybe try some DME instead?

 

[bw7hb]

I've used the same extract before successfully. I think it must be an infection in my plastic fermenter which has survived two cleans with sodium percarbonate (one after the previous batch and one before this batch) followed by a good starsanning.

I couldn't even taste the hops in yesterday's sample which seems strange. Must be an infection. I'll give this batch another week or so then I'll try a new fermenter.

The first two batches I ever did I only used sodium percarbonate for cleaning and sanitizing so I'm wondering if an infection was introduced into the fermenter in the second batch (first was fine).

 

[bw7hb]

The gravity has been stable for 3 days now. It tastes identical to all the previous batches with the really bad off flavor.
I've gone ahead and dumped the beer. Probably a bad idea to dump this early but past experience tells me it's not going to improve.

I think I must have a really bad acetobacter infection.
I understand it needs oxygen - does anyone know roughly how much oxygen it will take for acetobacter to ruin a beer? For example leave the fermenter open for a few days, or just open the lid once during fermentation.
Maybe I'm getting enough oxygen in there during the dry hop for acetobacter to run amok on on my beer which would explain why it's only happened to my dry hopped beers.
I did see a fruit fly near where I brew/ferment a few days ago.

 

[kh54s10]

The question of how much oxygen will lead to off flavors will get you wildly varying opinions. Some say they detect oxidization if they don't do closed transfers. I don't have the setup for that and have dry hopped, siphoned to a bottling bucket for bottling and have never had issues bad enough to even say I had oxidation at all.

It is possible to get microbes in plastic in a way that the only real solution is to replace the plastic.

I would try a new fermenter.

 

[bw7hb]

An update on this.
I've since got a new fermenter and brewed a different recipe which turned out great. It didn't have any dry hops.

After that I decided to try the NEIPA again in the new fermenter and it smells and tastes exactly like the previous ones. I didn't smell the off flavor prior to dry hopping so I'm certain it has something to do with dry hopping.

After extensive research I think it might be diacetyl caused by dry hop creep, and the buttery aroma usually associated with diacetyl might be mixed in with the hop aroma creating a very weird off flavor/aroma that I didn't initially detect as diacetyl.

I was drinking a real NEIPA from the shop and poured a bit of my latest attempt to compare.
When I smelt my one this time all I could smell was a horrible smell that is somewhat reminiscent of butter - without the fruity smell that I could detect before I'd drunk the proper NEIPA.
I reckon I couldn't smell the hop aroma of my beer since I'd just been drinking a hoppy beer, and therefore only picked up the other aroma which I think is diacetyl. An excellent diagnosis/smelling technique if this proves to be correct

I'd be glad of any suggestions as to how to try get rid of the diacetyl in this latest batch. Should I just remove from the fridge and let it sit for a week or so at room temperature?

EDIT: I'm pretty sure all of my attempts at this NEIPA have been dry hopped only a few days prior to cold crashing so that may help explain why diacetyl hasn't been cleaned up by the yeast.

 

[IslandLizard]

Thanks for the update!

Should I just remove from the fridge and let it sit for a week or so at room temperature?

To do a diacetyl rest at this point, you still need yeast in suspension. Do you think there is still enough in there? Or maybe add a fresh yeast starter at high krausen. Did you use US-05? Again, prevent any air/O2 exposure, whatever you do.

Next time give it a D-rest at 72-74F when adding the last dry hop, or during the last 4 days of the last dry hop. Perhaps taste some before cold crashing to make sure the diacetyl has been converted, and give it a few extra days if necessary.

It's a very strange phenomenon though. Maybe you are super sensitive to diacetyl or whatever it creates with the hops oils.

 

[bw7hb]

It's been cold crashing for 2.5 days now so probably not much yeast left in suspension. I used S-04 this time.
I'm actually using a BrewKeg now and it's under pressure; it would be difficult to pitch more yeast at this point.
I think I'm going to turn the fridge off for a week or so and see if I can get any conversion otherwise I might just dump it and start again.

It looks like someone else has confused diacetyl with acetaldehyde so that gives me a bit of hope that this is actually the issue.

 

[IslandLizard]

You could rouse the yeast back into suspension by inverting the keg a few times or rolling it.
Together with a temp rise to 72-74F that may be enough. I'm saying 72-74F as regular 68-70F conditioning at the end of fermentation doesn't seem to do it. After active fermentation is done, how long do you condition it at 68-70F?

On those Brewkegs, can't you remove and reseal the lid to add stuff?

Green apples and butter are very different off flavors. But I can see how a NEIPA dry hop load can change the butter perception. The malt background is so subdued too.

 

[bw7hb]

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?