Author Topic: Acetaldehyde in Lagers  (Read 643 times)

Offline denny

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Re: Acetaldehyde in Lagers
« Reply #15 on: April 24, 2021, 10:46:57 PM »
Thank you everyone, sincerely, for the replies. Sometimes I'm surprised at how willing people are to try to diagnose someone else's issues when that beer will never reach them anyways! haha! It seems the leader in the clubhouse is the extended cold crash with extended CO2 exposure. I have bottled half of the batch as suggested above, and the next lager I make I think I'll take it straight from fermenter to keg (when it is tasting totally fine) and skip the cold crash just to see what happens

I hope I don't seem like I'm picking on you,  but in this situation I always think....you followed the same basic procedures with basically the same ingredients and process as many of us.  So, why aren't there more reports of this? I always wonder if there's something we're all missing.
   

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Offline Carson B

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Re: Acetaldehyde in Lagers
« Reply #16 on: April 24, 2021, 10:56:54 PM »
Thank you everyone, sincerely, for the replies. Sometimes I'm surprised at how willing people are to try to diagnose someone else's issues when that beer will never reach them anyways! haha! It seems the leader in the clubhouse is the extended cold crash with extended CO2 exposure. I have bottled half of the batch as suggested above, and the next lager I make I think I'll take it straight from fermenter to keg (when it is tasting totally fine) and skip the cold crash just to see what happens

I hope I don't seem like I'm picking on you,  but in this situation I always think....you followed the same basic procedures with basically the same ingredients and process as many of us.  So, why aren't there more reports of this? I always wonder if there's something we're all missing.
   

I'm always after the most on-the-nose advice/criticism I can find. That's how you get better. I've seen people get very defensive on here, and that's not what I'm after. I appreciate all the honest feedback. I'm trying to figure out what I'm missing, too. There's always the chance I'm just tasting something different, and it's not acetaldehyde. But, that's my best guess. Fits the descriptors perfectly. Whatever it is is certainly not welcomed in my lagers!  ;D

Offline mainebrewer

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Re: Acetaldehyde in Lagers
« Reply #17 on: April 25, 2021, 10:15:36 AM »
You may want to try transferring your beer into the keg before it is completely finished. Purge the keg (either a sani or fermentation purge), when the beer is almost finished fermenting (3-4 points remaining) do a closed transfer to the keg and let the beer finish in the keg. The yeast in the beer will use up any remaining O2 in the keg and when the beer is finished it will be fully carbonated. A spunding valve will be helpful in monitoring the CO2 pressure in the keg.
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Offline majorvices

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Re: Acetaldehyde in Lagers
« Reply #18 on: April 25, 2021, 12:16:25 PM »
You may want to try transferring your beer into the keg before it is completely finished. Purge the keg (either a sani or fermentation purge), when the beer is almost finished fermenting (3-4 points remaining) do a closed transfer to the keg and let the beer finish in the keg. The yeast in the beer will use up any remaining O2 in the keg and when the beer is finished it will be fully carbonated. A spunding valve will be helpful in monitoring the CO2 pressure in the keg.

Not saying not to try this, but some of the ways mentioned to avoid acetaldehyde is by not racking too early.

Offline MNWayne

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Re: Acetaldehyde in Lagers
« Reply #19 on: April 25, 2021, 03:29:43 PM »
Whenever my lagers tasted a little "cidery" I attributed it to poor balance.  Insufficient bittering or excessive unfermentables.  Bittering is very process dependent. Maybe your 20 IBUs is not really 20.  Maybe some gypsum would help accentuate the hops a bit and offset what I'm guessing is an under-bittered beer.  I'm guessing here, I could be way off.
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Offline narcout

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Re: Acetaldehyde in Lagers
« Reply #20 on: April 25, 2021, 03:55:52 PM »
There's always the chance I'm just tasting something different, and it's not acetaldehyde. But, that's my best guess. Fits the descriptors perfectly. Whatever it is is certainly not welcomed in my lagers!  ;D

For $30, you could get it tested.

https://oregonbrewlab.com/products/#offflavor

If it's really driving you nuts, it might be worth it.
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Offline majorvices

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Re: Acetaldehyde in Lagers
« Reply #21 on: April 25, 2021, 04:03:52 PM »
That's worth the price IMO!

Offline denny

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Re: Acetaldehyde in Lagers
« Reply #22 on: April 25, 2021, 04:21:32 PM »
That's worth the price IMO!

Dana does amazing work.
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Offline mainebrewer

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Re: Acetaldehyde in Lagers
« Reply #23 on: April 25, 2021, 05:31:42 PM »
You may want to try transferring your beer into the keg before it is completely finished. Purge the keg (either a sani or fermentation purge), when the beer is almost finished fermenting (3-4 points remaining) do a closed transfer to the keg and let the beer finish in the keg. The yeast in the beer will use up any remaining O2 in the keg and when the beer is finished it will be fully carbonated. A spunding valve will be helpful in monitoring the CO2 pressure in the keg.

Not saying not to try this, but some of the ways mentioned to avoid acetaldehyde is by not racking too early.

Several of the previous suggestions were oxidation and questioning the CO2 purity. This would pretty much eliminate those from consideration.
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Offline RC

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Re: Acetaldehyde in Lagers
« Reply #24 on: April 26, 2021, 01:06:39 AM »
There's always the chance I'm just tasting something different, and it's not acetaldehyde. But, that's my best guess. Fits the descriptors perfectly. Whatever it is is certainly not welcomed in my lagers!  ;D

For $30, you could get it tested.

https://oregonbrewlab.com/products/#offflavor

If it's really driving you nuts, it might be worth it.

If I already know a certain off-flavor is in my beer, then wouldn't these off-flavor tests just be telling me what I already know?

Offline hopfenundmalz

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Re: Acetaldehyde in Lagers
« Reply #25 on: April 26, 2021, 01:42:46 AM »
Here is a reason to make sure your Keg is purged and the CO2 is as pure as you can get - when alcohol oxidizes it becomes acetaldehyde. Just saying.

Analysis of a beer for acetaldehyde would remove doubt. Why do I say this? Some yeasts produce apple esters. Not green apple, but ripe red Apple. We think apple=acetaldehyde, and that is not always true.

A test would say how much acetaldehyde is there. All beer has acetaldehyde, the goal is for it to be below human threshold.
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Offline erockrph

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Re: Acetaldehyde in Lagers
« Reply #26 on: April 26, 2021, 02:42:28 AM »
Here is a reason to make sure your Keg is purged and the CO2 is as pure as you can get - when alcohol oxidizes it becomes acetaldehyde. Just saying.

Analysis of a beer for acetaldehyde would remove doubt. Why do I say this? Some yeasts produce apple esters. Not green apple, but ripe red Apple. We think apple=acetaldehyde, and that is not always true.

A test would say how much acetaldehyde is there. All beer has acetaldehyde, the goal is for it to be below human threshold.

Right. It seems odd to me that you're having acetaldehyde issues across so many beers. All of the explanations I've seen so far really seem like a bit of a stretch. Acetaldehyde isn't typically a common problem. I think that if you're having issues with multiple beers, then either you're a supertaster for acetaldehyde, or it's probably something else.

Any chance you could have a low level infection somewhere in your system? Maybe some microbe is producing another flavor compound that is coming across as apple?

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Offline MNWayne

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Re: Acetaldehyde in Lagers
« Reply #27 on: April 26, 2021, 01:22:14 PM »
Does the flavor present itself with other yeast strains?  What about ferment temps?  If you are only controlling ambient ferment chamber temperature without monitoring actual wort temp, you may be fermenting way warmer than you think.
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Offline hmbrw4life

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Re: Acetaldehyde in Lagers
« Reply #28 on: April 26, 2021, 01:26:13 PM »
Wyeast 2308 Munich Lager pitched at proper rate after starter

Whats the "proper rate"?
Has this rate been verified with a scope and a count? If using a online calculator, I have found them from mildly to wildly inaccurate (but not one right). This is from scoping and actually counting.
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Offline majorvices

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Re: Acetaldehyde in Lagers
« Reply #29 on: April 26, 2021, 01:44:09 PM »
Acetaldehyde isn't typically a common problem.

I disagree with this. It's one of the more common problems, especially in lagers. I think if it is a problem with process it becomes more evident in delicate lagers as opposed to stronger flavored lager.

Don't mean to set everyone barking up the wrong tree with the Co2 impurity comment either. Just the OP says he only noticed it after the beer was kegged and carbbed. Of course it seems like lots of off flavors work that way.