Twin IPAs, fermented separately with two different yeast strains

So I'm experimenting with different yeasts in order to determine their traits in a West Coast style American IPA with a relatively clean grist, 90 IBU, hopbursted, and soon to be dryhopped.

I brewed up 7 gallons and split the batch into two carboys. Brewday was Nov 11. OG was 1.069.

In the first carboy, I pitched a starter of Wyeast London Ale 1028. The second got a WLP090 San Diego Super starter. Both yeast packs were about 2 to 2.5 weeks old at the time of use. I created an appropriate sized starter for each and followed all the proper processes.

I just pulled a sample from each carboy. Both FG's read 1.012 so identical attenuation (58-63 F air temp. fermentation range for the first week, and now 64-67 F air temp. conditioning range). Sorry, no probe thermometer to constantly measure the actual temperature.

7.6% abv with over 82% apparent attenuation??? Pats self on back if true.

The part I'm concerned about is the taste. I know this is not the final beer at day 15 in the primary before the dryhop, priming, and further conditioning.

The San Diego Super sample tastes very smooth. It's a tiny bit harsh/green, but overall, it's just what I was after. However, the London Ale sample tasted super harsh of fusel alcohol. I kept getting whafts of hot alcohol upon each sip. In short, the 1028 sample was very off putting despite otherwise being an identical beer.

Will more time solve this? What is the culprit if any?

I made a 10 gal batch split 4 waywith diff yeastys and all 4 beers tast like somthing elts, yeast sure plays a key roll in flavoring , I continue to explor the meny diff flavors yeast can offer and I comenly pratice using two diff yeasts on 10gal batches

Waaay to early to tell. I remember trying some East Coast Patriot yeast that gave the beer a very sour smell and taste to the point I almost decided to dump it than waste time bottling it. 3-4 weeks in the bottle, sour was gone, and it ended up being one of my better IPA's I've made. I wish I kept the yeast as well, instead of dumping it. Lesson learned.......give it time to mature.

I usually brew with US-05 or S-04 and the English yeast needs lower temperatures to be fine, the US-05 doesn't ferment good in the lower side of the spectrum unlike the S-04 but in the medium to medium-high side of the spectrum the US-05 does it great unlike the S-04 which I'd describe just as you did with the 1028.

Maybe its the same.

Waaay to early to tell.

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Unfortunately fusels (if that's what he's sure it is) don't really go away even w/ extended conditioning.

What is the culprit if any?

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What temperature did you pitch at and what does your aeration process look like?

Oh and I'm currently reading the Brewing Elements book on yeast (which is fantastic BTW), and just read through the chapter today discussing fusel alcohol production and what can increase it.

The most common causes from the book:

- High OG
- High temps
- Over-pitching
- Over-aeration (pretty much impossible here unless you're using pure O2)

The only thing on that list that "may" be an issue is pitching the appropriate amount of yeast. If anything, I may have slightly underpitched the 1028. Perhaps the fusels are from stressed yeast in general. I just don't understand why one yeast is exhibiting those fusel/rubbing alcohol traits while the other is not.

I pitched the starter slurry when the wort was 64 F. The air temp. where the fermenters sat was more like 58-62 F.

CharlosCarlies said:

Unfortunately fusels (if that's what he's sure it is) don't really go away even w/ extended conditioning.

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Yes they do.

Stressed yeast is probably the culprit, but that is a vague reason that can have numerous causes. I would think under-pitching or poor oxygenation would most likely be the causes in this case.

I'll quote someone on this because he explains it quite well...

FlyGuy said:

Fusels are a symptom of stressed yeast. Warm temperatures, especially in combination with too little yeast or poorly aerated wort, are the typical cause. You generally never hear of anyone attributing it to over-pitching (you would have to pitch obscene amounts of yeast) or from effects of trub/lack of a secondary.

Here is my advice (based on a number of fusel-ridden batches):
- be SURE you are fermenting cool enough. Even if ambient temps are 70F, the yeast will generate heat of its own up to 10 degrees higher (I didn't know this before and it was the cause of my problem). Admittedly, though, a water bath should help.
- always pitch enough yeast and aerate really well so that yeast aren't stressed, particularly for higher gravity beers
- protect your beer from temperature fluctuations (fermenting in your water bath should help, assuming there is a good volume of water there)

Despite what many people will tell you, the good news is that the hot-alcohol taste of fusels will begin to disappear over time, if you are patient. The bad news is that it takes months (not all beers will last this long), and it never goes away completely.

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Yes they do.

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I could be wrong here and if so my apologies, but I'm almost positive I've read from several sources that fusels don't condition out (at least not nearly to the extent that other flavor compounds do).

My own personal anecdotal evidence at least backs it up as well. One such example was a 1.100 barleywine that I stupidly pitched onto a full US-05 cake. Fermentation took off so rapidly that I had trouble keeping temps within range and the resulting beer unsurprisingly was a completely undrinkable fusel bomb. I forgot about it and let it cellar for over a year, and it had barely changed at all.

Just my 2 cents, so if you have evidence to prove me wrong I'm very interested in seeing it.

I would think under-pitching or poor oxygenation would most likely be the causes in this case.

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I would have thought so as well, but I'm taking this straight out of a chart in "Yeast: The Practical Guide to Fermentation" by Jamil and Chris White (from White Labs).

The most common causes from the book:

- High OG
- High temps
- Over-pitching
- Over-aeration (pretty much impossible here unless you're using pure O2)

Just out of curiosity, how would anyone here classify over-aeration? Would this be an extreme situation, or could a few extra volumes have a dramatic effect?

Because I do use pure oxygen, and my last few high gravity ales got me wondering if over airing led to a slightly interesting flavor I noticed. Just a thought.

Anybody else use medical grade oxygen?

CharlosCarlies said:

Just my 2 cents, so if you have evidence to prove me wrong I'm very interested in seeing it.

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Outside of my own homebrewing, here's one source.

The most recent BYO (December 2012) has an article on Strong Ales. A quote:

"'If you have the time, I would store cool (50*) or cold (35*) for at least a month to let the fusel alcohol flavors simmer out a bit.' says Rob Denton, Assistaant Brewer at Snake River Brewing Company & Brewpub in Jackson, WY. 'Even longer is better'".

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Also, Duvel uses the 'psuedo lagering' secondary stage that is described above.

As you could probably guess, I use the Duvel method for all of my strong ales. Ferment starts low, rises to the high end of the yeast's range, finishes at my desired FG, then I take the whole fermenter, yeast cake and all, down to 40*. Keep it there for a month and let the magic happen. Am I saying that solvent/rubbing alcohol will go away entirely? No. I'm saying that they calm and can be virtually impossible to detect after a cool secondary. Case in point: my 9.5% BGSA drinks like a 4.5% beer. YIKES.

mash_trub_hater said:

Just out of curiosity, how would anyone here classify over-aeration? Would this be an extreme situation, or could a few extra volumes have a dramatic effect?

Because I do use pure oxygen, and my last few high gravity ales got me wondering if over airing led to a slightly interesting flavor I noticed. Just a thought.

Anybody else use medical grade oxygen?

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I use (well, used to use I guess) pure O2. It is possible to over-oxygenate (which can cause acetaldehyde). I turned on the pure O2 and forgot about it until 3 minutes later... the whole new bottle was gone. Whoops!!

That being said, anything over 15-20ppm O2 would be quite high.

I've now switched to a mix-stir.

Update on the alleged fusel notes in the 1028 IIPA...

Bottled both beers. The 1028 beer tastes like alcohol/solvent hairspray, whereas the WLP090 beer tastes great. Still confused as to the cause. Both beers are identical otherwise and treated similarly. They were definitely not fermented too warm. And I hit all my numbers for both beers as expected.

AmandaK said:

Outside of my own homebrewing, here's one source.

The most recent BYO (December 2012) has an article on Strong Ales. A quote:


Also, Duvel uses the 'psuedo lagering' secondary stage that is described above.

As you could probably guess, I use the Duvel method for all of my strong ales. Ferment starts low, rises to the high end of the yeast's range, finishes at my desired FG, then I take the whole fermenter, yeast cake and all, down to 40*. Keep it there for a month and let the magic happen. Am I saying that solvent/rubbing alcohol will go away entirely? No. I'm saying that they calm and can be virtually impossible to detect after a cool secondary. Case in point: my 9.5% BGSA drinks like a 4.5% beer. YIKES.

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So is it the poor flavor of the fusel that is gone, or the fusel alcohol itself is no longer present? I'm thinking about it tasting good, but still giving you a headache.

Rick