38 replies to this topic

[strangebrewer]

I think Acetobacter can produce some too but you'd be getting vinegar flavors in that case.

Actually I've gotten Acetaldehyde from acetobacter without the vinegar particularly in lighter beers. I'm thinking it's a matter of taste thresholds where the acetaldehyde shows up first as it has a much lower detection threshold compared to acetic acid.Neither Lacto or Pedio will throw acetaldehyde in my experience. Lacto throws lactic acid (go figure) which is tart but light on the palate and the first thing Pedio really throws is diacetyl. mmmmm ropey butterscotch.You could still have a contamination issue. If you're willing to give it a peek I'd take a look in the keg to see if you have a layer of something on top. Other than acetobacter I had a similar green apple/ green olive flavor when doing a series of open fermentation experiments. I let it primary with 1056 but left it open to the elements for the following 2 weeks post ferment. While most ended up with acetobacter I had 2 develop a stark white krausen/pelicle thing. It didn't sour the beer but it also didn't taste very good IMO.

[Humperdink]

Appletinis!!!

[Humperdink]

Actually I've gotten Acetaldehyde from acetobacter without the vinegar particularly in lighter beers. I'm thinking it's a matter of taste thresholds where the acetaldehyde shows up first as it has a much lower detection threshold compared to acetic acid.Neither Lacto or Pedio will throw acetaldehyde in my experience. Lacto throws lactic acid (go figure) which is tart but light on the palate and the first thing Pedio really throws is diacetyl. mmmmm ropey butterscotch.You could still have a contamination issue. If you're willing to give it a peek I'd take a look in the keg to see if you have a layer of something on top. Other than acetobacter I had a similar green apple/ green olive flavor when doing a series of open fermentation experiments. I let it primary with 1056 but left it open to the elements for the following 2 weeks post ferment. While most ended up with acetobacter I had 2 develop a stark white krausen/pelicle thing. It didn't sour the beer but it also didn't taste very good IMO.

FWIW, there was no pelicle or anything out of the ordinary looking at the time of kegging. I'll crack it open tonight when I dry hop and give her a look see. I'm not inclined to think it is an infection, though like I said I am open to any possibility since I've never had this happen with this yeast before. I'll dive in face first tonight rather than bludgeoning my palate first to see if there's been any change. Also FWIW, my buddy can't taste it and my SWMBO doesn't find it as apparent as I do, she generally has a better palate than I do, damn it.

[strangebrewer]

Doesn't Acetobacter need o2 to produce vinegar? If he picked up the Acetobacter in the keg purged with co2, it may produce little to no acetic acid.

Yes it does require O₂ to do its thing. You posted as I was typing my response but as I noted acetaldehyde has a much lower taste threshold so it could still be acetobacter causing the off flavor it just hasn't had time to make enough acetic to be noticeable.

[MtnBrewer]

Doesn't Acetobacter need o2 to produce vinegar? If he picked up the Acetobacter in the keg purged with co2, it may produce little to no acetic acid.

I thought it needed O₂ to produce anything at all.

[Humperdink]

I'll report back to see if I pick up any oxidative character, but I did rack into a purged keg so I'm not sure where the 02 pickup would have been.

[Humperdink]

On a happier note my draft system made it into the NB catalog this month. WOOHOO!

[japh]

I thought it needed O₂ to produce anything at all.

Not sure about Acinetobacter, but in humans:

In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase.

[Thirsty]

On a happier note my draft system made it into the NB catalog this month. WOOHOO!

Congrats! I just got mine in the mail today, and had to pull it out of the trash to check it. I usually flip through it, but have no extra $$ right now, and there is too much temptation, so I tried to seperate myself from it! Are you Tom, Ron, Chad, Dan, Andy Cody, or Jared?

[Humperdink]

Congrats! I just got mine in the mail today, and had to pull it out of the trash to check it. I usually flip through it, but have no extra $$ right now, and there is too much temptation, so I tried to seperate myself from it! Are you Tom, Ron, Chad, Dan, Andy Cody, or Jared?

??? page 54 chris cose? a buddy forwarded me his PDF copy since I haven't received a copy in a few months.from my desktop picture

[Thirsty]

??? page 54 chris cose? a buddy forwarded me his PDF copy since I haven't received a copy in a few months.from my desktop picture

It has got to be a proof for the following catalog, I really just got this one in today, it has an all black cover with like a "ghosted" image of a silhouette. Again congrats and we'll keep our eyes open!BTW, nice setup!

Edited by Thirsty, 16 December 2009 - 04:28 PM.

[Humperdink]

It has got to be a proof for the following catalog, I really just got this one in today, it has an all black cover with like a "ghosted" image of a silhouette. Again congrats and we'll keep our eyes open!

Hell, maybe it was last months. I just found out yesterday. I haven't been receiving mine since I moved.

[Humperdink]

No oxidative character that I could see with a thorough evaluation last night the offending flavor seems to have died back to a detectable but not overpowering level. I'll drink the keg. Not the best beer ever, but definitely better than it was last week. Thanks all for your input.

[MtnBrewer]

No oxidative character that I could see with a thorough evaluation last night the offending flavor seems to have died back to a detectable but not overpowering level. I'll drink the keg. Not the best beer ever, but definitely better than it was last week. Thanks all for your input.

Just curious, why were you looking for oxidation?

[Humperdink]

Yes it does require O₂ to do its thing. You posted as I was typing my response but as I noted acetaldehyde has a much lower taste threshold so it could still be acetobacter causing the off flavor it just hasn't had time to make enough acetic to be noticeable.

I thought it needed O₂ to produce anything at all.

Just curious, why were you looking for oxidation?

Curious to see if I could pick any up. And given the quotes it made me want to look. You all were talking about acetobactor needing oxygen to produce anything at all. I didn't detect any, and I understand that doesn't mean much either way given that acetobactor would consume the oxygen, no?That and the talk of oxygen converting ethanol back into acetaldehyde. Just seemed like something for me to look into.

[MtnBrewer]

Curious to see if I could pick any up. And given the quotes it made me want to look. You all were talking about acetobactor needing oxygen to produce anything at all. I didn't detect any, and I understand that doesn't mean much either way given that acetobactor would consume the oxygen, no?

Right but it never hurts to look. I wouldn't expect you to detect any since if there was acetobacter present, it would have consumed most or all of the oxygen. Also the beer isn't old enough to show any signs of oxidation.

[Humperdink]

Right but it never hurts to look. I wouldn't expect you to detect any since if there was acetobacter present, it would have consumed most or all of the oxygen. Also the beer isn't old enough to show any signs of oxidation.

Thanks mtn

[Deerslyr]

Touche.......ETA:Engrish fail

Not an Engrish fail... more like a "Oui oui, you Frenchie bas-terd!" fail.

[Humperdink]

Not an Engrish fail... more like a "Oui oui, you Frenchie bas-terd!" fail.

I think you just nominated yourself for a new comptroller position there Mr advanced member.