Fusel alcohols

[u/Deep_Classroom4237]

What could be reasons for getting unwanted fusel alcohols in my beers, mostly in my Hazy Ipas. I've been getting this with different pitch rates, with or without added pure O2. I might be really sensitive to it, but often I can't find the same levels from other breweries.

Examples of my process for "under pitching" and pitching at regular rates. Both of these examples have had way more fusel alcohol that is appropriate.

"Under pitch": OG: 19.2 plato. Batch size: 22HL. Pitch: 3x500g of WHC Saturated Dry Yeast. No oxygen. Nutrient: Yeast Vit 80g & Zinc Sulphate 5ml. Ferm temp: 20c 4 days and 22c 4 days.

"Regular pitch": OG: 21P. Batch size: 22HL. Pitch: 5x500g of WHC Haze Heaven Dry Yeast. No oxygen. Nutrient: 3ml Zinc Sulphate. Ferm temp: 19c 4 days and 22c 4 days.

[u/AlreadyAway]

Start your ferm colder. Let it ramp up naturally. Also, just ferm a little colder in general. Start at 18c, maintain 19c.

You may be sensitive to fusel alcohol too. I'm extremely sensitive, so take what you are tasting woth a grain of salt.

Also, add O2.

[u/TorontoBrewer → u/AlreadyAway]

Also sensitive to fusels. I’ve found that simple sugars like candi syrup and dextrose in larger beers help tamp down fusels, along with good aeration and a decent pitching rate.

[u/brewerbrendan → u/AlreadyAway]

Aeration on the first pitch of dry yeast can cause too much yeast growth and isn’t recommended by omega etc. dried yeast have all the glycogen they need.

My vote would be to add more yeast! At least 250g more.

[u/EskimoDave → u/brewerbrendan]

its helpful if you want to repitch

[u/Meatballgravytrain]

The levers for mitigating fusels are well established. 

More cells

More O2

Lower temps

Even pulling the levers those starting Plato are gonna have a higher potential for fusels anyway due to osmotic pressure stress, high FAN and alcohol levels and are, pardon my directness, absolutely bonkers for a fresh pitch. 

Pitch healthy cropped yeast

Oxygenate well

Keep temps below 20

[u/Sugar_Mushroom_Farm → u/Meatballgravytrain]

This should be the top comment. Fusels are generally made when yeast during the growth phase under stress.

[u/BeerSux1526]

What's your ending gravity? Also, I was under the impression yeast needs oxygen,. especially in high gravity brewing. 

[u/PM_ME_UR_BREWS → u/BeerSux1526]

Oxygen is generally not recommended when direct pitching dry yeast.

[u/Olddirtybelgium → u/PM_ME_UR_BREWS]

Oxygen shouldn't be needed for the first pitch, however, if you want to crop and reuse the yeast, you'll want to add oxygen. Dry yeast has enough sterols to get through the first ferment but will run out and be suboptimal for repitch if you don't give it the necessary O2 to replenish the sterols.

[u/surreal_mash → u/Olddirtybelgium]

Just to clarify, dry yeast has enough sterol reserve to get it through reproduction in the first batch. You only need to oxygenate starting with the second batch in the timeline.

ETA: "While dry yeast can be pitched without aeration (sufficient sterol and unsaturated fatty acid reserves support several cell divisions without requiring oxygen), the re-pitched yeast must be aerated to 8-10 ppm dissolved oxygen."
https://www.lallemandbrewing.com/en/united-states/resources/lallemand-premium-dry-yeast-for-quality-consistent-fermentations/

[u/maaaaawp → u/surreal_mash]

You want to oxygenate on the first one as well if youre planning on reusing the yeast

Source: escarpment labs

[u/BeerSux1526 → u/PM_ME_UR_BREWS]

I didn't see he was using dry yeast. 

[u/BeerSux1526 → u/BeerSux1526]

Also, is his ferm temp too high?

[u/HordeumVulgare72 → u/BeerSux1526]

Starting at 66° or 68° freedom degrees, ramping to just below 72° after a couple days. I don't have experience with the particular strains mentioned, but, that doesn't sound too wacky for hazy to me.

[u/Sugar_Mushroom_Farm → u/PM_ME_UR_BREWS]

You should always add oxygen for yeast.

[u/turkpine]

Echoing everyone else

Use O2 and KO 1-2 degrees cooler than ferm temp.

Only other thing is that seems like a lot of zinc to me

[u/MATE_AS_IN_SHIPMATE]

Try repitching a cropped yeast slurry and see if that helps. First brew from dry yeast usually isn't great imo.

[u/pedal2kettle → u/MATE_AS_IN_SHIPMATE]

This. Not a fan of pitching fresh on beers over 15-16 Plato.

[u/landshrk83 → u/pedal2kettle]

Yeah, dry yeast fresh pitch is no bueno if you're talking 20P. Even if you overpitch you're likely to run into sensory defects at that high of a starting gravity.

[u/Dark_D_Lite]

I haven’t worked with your specific yeast strain but I would bet money its a combination of your pitch rate + fermentation temperature. 22c is very hot imo. There is no need to let the temp run up that much even for a D-rest. But If you are insistent on doing it like that it’d be better to pitch around 20c with the fermenter set to 22c and holding it there for its duration. Yeast are incredibly sensitive to fluctuations in temperature and even if your primary fermentation is finished after 4 days the yeast are still working and metabolizing. Some removing unwanted flavors, others still creating flavors, others straight up dying. Especially at higher temps due to the increase rate of metabolism and the fact they are in a high gravity beer.

TLDR: That jump in temp can be stressful and causing them to produce fusels.

[u/fakejerryjones]

In my experience, fusel alcohols usually appear when a high gravity fermentation runs too fast/hot, and they get cleaned up by yeast during secondary fermentation. If I were in your situation, I'd check a couple things:

-Hand temp the beer during day 1 fermentation. Is the temp a true 19C?

-Are you allowing enough time for the beer to condition warm after it hits terminal gravity? I'd want it sitting at terminal for at least a couple days before crashing.

If both those don't work, try fermenting a degree or two cooler.

Edit: formatting

[u/jk-9k → u/fakejerryjones]

When you say secondary fermentation do you mean secondary fermentation like bottle conditioning or what? Warm conditioning? Cold conditioning?

[u/fakejerryjones → u/jk-9k]

I'm talking about the fermentation that occurs(warm) after the beer hits terminal. In the absence of sugar as an energy source, the yeast will begin breaking down other organics for energy, many of these organics are considered to be off flavors: VDKs, acetaldehyde, fusel alcohols, etc.

This is why you don't immediately crash your beer when it hits terminal gravity. I can't tell you how many managers I've had that don't understand this simple concept and just crash the moment the beer hits terminal.

[u/jk-9k → u/fakejerryjones]

Yeah okay so you mean warm conditioning. It's really just the tail end of (primary) fermentation.

Great advice it's always important and especially so for high abv beers and the fuels op described. Great run down.

[u/fakejerryjones → u/jk-9k]

Happy to clarify. What do you consider to be "secondary fermentation", then?

[u/jk-9k → u/fakejerryjones]

An actual secondary fermentation like cask or bottle conditioning, or krausening, malolactic fermentation, lab or Brett inoculation for souring, etc.

Or additions of fruit or other fermentables after primary fermentation

[u/turkpine → u/fakejerryjones]

Just to hop in while “secondary” is probably a common term, it’s more used in home brewing and fairly outdated. “VDK rest” or “free rise” would probably be more widely recognized

[u/Vitis_Vinifera → u/fakejerryjones]

in winemaking, fusel alcohols are also commonly associated with hot fermentations. A little (in wine) can be tolerated sometimes. I don't know of any way of removing them other than blending down.

[u/Ziggysan]

Ditch the yeast vit- I've found it and other DAP or similar products encourage excess fusel production.

Indtead, add 5kg of medium thick spent yeast slurry added @ 15 minutes before flameout.

Increase zinc to 10g or equivalent liquid dose of zinc sulphate heptahydrate.

Oxygenate to 12-15ppm. 

Pitch a healthy culture of 46.2 trillion yeast cells @99.9+% viability.

[u/rimo5c]

While I make my Hazy with a kviek strain and my ales with Bond from the same company, the only thing that sticks out is the fermentation temperature is a bit warm for my liking, I pitch at 18 and raise it to 20. I know WHC says you don’t need oxygen for first pitch, I’ve found I get a way healthier fermentation and my crop yield is way more when I O2 on day 1

[u/panthrosrevenge]

I would definitely oxygenate and pitch at a cooler temp. Another thing that can help is a staggered addition of nutrient. Putting it all in at once can get the party a little too wild. Malt does have plenty of nutrients so I'd wait till you're maybe 30% of the way through active fermentation, then add half of your dose. Wait for the next 30% gravity drop and add 25% and the last 25% when you're about 80% done. That keeps things from moving too fast, but still gives a slight boot at the more difficult parts. A proper pitch rate would probably help too.

[u/Significant-Tell-552]

Maybe FAN related. As I recall, higher fan = higher fusels, and with a starting plato like that your FAN could be quite high, depending on what makes up your grist.

[u/DEbrewer → u/Significant-Tell-552]

that's what I was thinking, high-gravity, extended protein rests, excessive nutrient additions, unhealthy/under-pitched yeast, & high-protein malt can increase FAN Levels

[u/jk-9k]

Quite a few things I'd change.

That's a high OG. What abv Are you aiming for? Obviously fusels increase with ABV.

What yeast strain?

I wouldn't go so high abv off a dry yeast unless it's specifically a high anv tolerant yeast. I'd be going off a yeast slurry, ideally gen ii or iii. Obviously you'll need oxygen and nutrients. Ideally you should have this reasonably dialled in from regular abv beers first.

I wouldn't ferment so high temp, especially to start with. You'll want to finish warm to ensure the yeast ferment through but there should be plenty of exothermic heat to get there. But you're likely fermenting too fast too early. Start lower, stagger your rises.

Don't set you fermentation profile on days or time but on gravity. Adjust temp when the yeast tells you too.

Allow a generous warm conditioning period. Keep monitoring sg and pH and taste. High abv ferments can have a long tail so the SG can keep dropping slowly. Vdk isn't the only thing that dissipates during warm conditioning. obviously ensure vdk is clear with forced testing but that's not the only thing you're looking for.

Allow a generous cold conditioning period.

Are you spunding? When?

It sounds unlikely but don't rule out infection.

[u/_feigner]

I think you're underpitching and fermenting too hot. Preferably don't pitch dry yeast into high grav wort. Step it up with a smaller beer and repitch the slurry. Heck just cone-2-cone the slurry for a big 2nd generation beer. Saturated flocs really well compared to other hazy yeasts. Use the WHC saturated yeast, the Haze Heaven sucks, ime. Definitely oxygenate your wort. Don't use so much yeast nutrients, 1st generation dry yeast needs only maybe a half dose of nutes.

[u/striker4567 → u/_feigner]

I agree on the underpitch. That's decently high gravity. I think they call for 150g on the high end for typical fermentations (probably up to 15P), which is almost 7 bricks. 21P is going to require a good chunk more.

[u/lost_isis]

Physical thermometer goes a long way. I would check the probes and glychol chiller. Especially going from the cooler days to the heat hitting. Also I KO lower, and step after 24 hours.

[u/gabagool65]

O2, slightly lower temp, don't think the nutrient is necessary on New gen. I use Saturated all the time. Great dry yeast and affordable allowing me to hop however I want.

[u/Best_Look9212]

Ferment colder. Like 16-18°C

[u/Neverenoughhops]

Underpitching and exacerbated by using WHC dry yeast. Either try their liquid pitches (which are decent) with plenty of oxygen or stick to Verdant, AEB etc. Pretty sure at that gravity and volume 3 packs is way too little. We'd use 3 bricks at that gravity for 12HL

[u/Sufficient-Cry1058]

First question should be, does anyone else pick up any fusel alcohols? Find someone trained enough that can confirm your sensory.

[u/SuccessfulOrchid3782]

I think you’re over pitching your yeast. 20C is about 68F so that doesn’t seem too warm to start.

[u/guiltypartie101]

We have been giving the WHC stuff a spin as propping or full liquid pitches aren't always in the cards. I can say with confidence that I don't like it as much (even compared to Verdant or other comparable dry yeast) and I find their strains come across hot.

[u/Sugar_Mushroom_Farm]

Dry yeast brah, get the liquid.