Off flavor, help me figure this out

[CrustyBrau]

So, a few batches back, I did three almost identical batches in a row. These were a Snow Cap clone, FWIW. The first and last were good, but the middle one had a weird flavor to it. I'm now reading about autolysis, and thinking maybe that was it, even though I can't find a taste description that really jumps out at me as "that's it, that's what I tasted".

The first and last batch, I used White Labs California Ale yeast, pitched right out of the vial. On the middle batch, I used a Wyeast American Ale smack pack. I smacked it pretty early, and by the time I pitched it, it was puffed up good and firm. That batch went ape sh*t and blew the lid off the fermenter and put quite a bit of foam out on top of the fermenter, while the White Labs batches never even put anything up in the bubbler. Now I'm reading that over pitching can cause increased autolysis, and I think maybe my smack pack batch was over pitched.

The best way I can describe what that batch tasted like is, a tasteless citrus like sourness, combined with a thinner than normal mouth feel. Almost like it had lime juice in it. Not enough to make it bad, and I don't even think my wife noticed it, but it was very obvious to me. There was no "rotten" smells, no yeastiness, or anything else. Just the odd sour overtone.

Autolysis ya think? Or?

 

[Six_O_Turbo]

I doubt it was autolysis. The smack pack would not have enough yeast to overpitch a 5 gallon batch, plus autolysis just doesn't happen often with the quality of todays yeast and normal fermentation times. It sounds like you may have fermented the middle batch a little too warm, or maybe it jumped in temp significantly at some point during fermentation. Also, if it blew the lid off your fermenter, it is possible that it was infected by wild yeast that could cause some sourness and thin mouth feel.

You may want to give more details on fermentation temps, time in the fermenter, and recipe info.

 

[Yooper]

I doubt it was autolysis. The smack pack would not have enough yeast to overpitch a 5 gallon batch, plus autolysis just doesn't happen often with the quality of todays yeast and normal fermentation times. It sounds like you may have fermented the middle batch a little too warm, or maybe it jumped in temp significantly at some point during fermentation. Also, if it blew the lid off your fermenter, it is possible that it was infected by wild yeast that could cause some sourness and thin mouth feel.

You may want to give more details on fermentation temps, time in the fermenter, and recipe info.

I agree. In fact, you probably underpitched. Autolysis has several descriptions but I think the one "meaty" is a good one. If your beer tastes like hot dogs, it very well good be autolysis.

"Sour" could be very early lactobacillus. I've had some sour flavors in the bottle in the past, but usually managed to drink them before they got worse. Lacto is my guess at this point, but it does sound like an infection and not a yeast issue.

 

[CrustyBrau]

"Sour" could be very early lactobacillus. I've had some sour flavors in the bottle in the past, but usually managed to drink them before they got worse. Lacto is my guess at this point, but it does sound like an infection and not a yeast issue.

Infection seems possible, since the top was off for several hours. But, wouldn't an infection get worse rather quickly? Or do you think maybe the infection died down/out when fermentation completed and I chilled the beer? This batch should have been at least 7% ABV.

 

[CrustyBrau]

I just went and read a bit about lactobacillus on Wikipedia, and now I think I have a better description for the off flavor in this beer. I'll just leave it at that

 

[CrustyBrau]

you probably underpitched.

Why do you say that?

 

[android]

Why do you say that?

because normally those vials/smack packs, even though they say you can pitch it into 5 gallons, do not contain a high enough cell count for the "proper" pitching rate.

 

[malkore]

because normally those vials/smack packs, even though they say you can pitch it into 5 gallons, do not contain a high enough cell count for the "proper" pitching rate.

And I agree...I recently joined the local brew club, and there are some pro brewers in the club. They've noted acetylaldehyde in most of my beers they've tasted...not enough to 'ruin' but enough they can notice.
And of course...those beers were underpitched with a white labs vial and no starter.

Yeast pitching and fermentation temp are crucial. You can have a great grain bill and hop schedule, but a weak beer if your yeast is 'wrong' in any way, shape or form.

www.mrmalty.com should give you ideal pitching rates for your OG.