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HELP - Acetaldehyde - Green Apple Sour Flavor

http://canyoubrewit.com/forum/viewtopic.php?f=5&t=19026

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HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 05, 2010 5:41 am
by IndianBeerGeek
I fermented my beer for a week and then primed and bottled. The beer is clear and well carbonated and clear. However, the taste is very sour. Just like green apple - Acetaldehyde. The bottles are still in the cabinet at room temp.

Question: Will keeping them in the cabinet for another week or so remove the green apple flavor? Or, would it be better to put them in the fridge (since they are already carbonated) and let them sit for a couple of weeks.

Damn! Such a nice looking beer and such a sour taste!! HELP.

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 05, 2010 6:28 am
by Elbone
Acetaldehyde is a byproduct of fermentation that is eventually cleaned up by the yeast. If you pull your beer off the yeast before they've had a chance to clean up after themselves, you can have acetaldehyde left in your beer. I believe that's what happened to you. 1 week is an awfully short amount of time between pitching and bottling. I wait until all activity in the airlock has ceased, then wait a couple of more days to be sure, then rack into a keg. For most ales this works out to two weeks in the primary and for lagers three or four weeks. If your beer was in a keg, you could make a small yeast starter and pitch it into your keg at high krauesen, let it sit at fermentation temps for a few days and the yeast would finish metabolizing the acetaldehyde.

Leave you bottles warm and the yeast in the bottle MAY clean up the acetaldehyde for you after a few more weeks. Next time, give the beer more time on the yeast.

If it's really sour, you may also have an Lactobacillus infection. Keep it clean.

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 05, 2010 6:32 am
by ajdelange
I guess I'd put half in one place and the other half in the other to see which, if either, treatment improves them. If the flavors are as strong as you suggest the probable culprit is infection and nothing is going to save the beer. But let's take note that infected beers are usually not clear and hope I'm wrong about this and that you are just very sensitive to acetaldehyde (which does taste/smell like apple or rotten apple at low concetrations but is not sour).

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 05, 2010 7:27 am
by siwelwerd
IndianBeerGeek wrote:I fermented my beer for a week and then primed and bottled.


There's your problem. I like to give mine a week after the gravity has stabilized for the yeast to clean up after itself (things like Acetylaldehyde and Diacetyl are the big ones).

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 05, 2010 8:01 am
by IndianBeerGeek
Thanks guys. It is heartening to learn that all may not be lost. As suggested, I will put some bottles in the fridge and leave the rest at room temp. Hopefully the yeast on the bottle will do it's job. Will post an update in a couple of weeks. Also I have an English pale ale in the fermentor which I will leave for another week as well. Cheers!

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 05, 2010 8:26 am
by Evan B
I typically leave my beers in the fermenter for AT LEAST 2wks. Just because you're not seeing activity doesn't mean the yeast isn't working.

However, I've never had something with so much acetaldehyde that is was sour. You may have some other things happening, infection maybe? Hard to tell. Just leave it in there for longer next time.

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Fri Feb 12, 2010 5:17 am
by Nyakavt
Evan Burck wrote:I typically leave my beers in the fermenter for AT LEAST 2wks. Just because you're not seeing activity doesn't mean the yeast isn't working.


+1, it's a great idea to taste the beer before you bottle/keg it to make sure you don't have any fermentation off flavors that can only be cleaned up with yeast contact. I have had a batch of Munich Helles that was very green apple after being carbonated, it took another 2 weeks at room temperature in the bottle (4 weeks total) to lose the flavor. Warm will help you here, especially if you packaged it already.

Re: HELP - Acetaldehyde - Green Apple Sour Flavor

Posted: Sat Feb 13, 2010 9:12 am
by Mylo
IndianBeerGeek wrote:I fermented my beer for a week and then primed and bottled. The beer is clear and well carbonated and clear. However, the taste is very sour. Just like green apple - Acetaldehyde. The bottles are still in the cabinet at room temp.

Question: Will keeping them in the cabinet for another week or so remove the green apple flavor? Or, would it be better to put them in the fridge (since they are already carbonated) and let them sit for a couple of weeks.

Damn! Such a nice looking beer and such a sour taste!! HELP.


If it is SOUR and green apple, then you have something else going on. Aceytlaldehyde does smell and taste like green apples, but without the sourness.

I agree with some of the other posters - 1 week CAN be too short to leave the beer on the yeast. If you pitched a fuckload of really viable yeast, then one week is probably fine. I would say that you either 1) underpitched, 2) had a bad vial (I did 6 months ago), or 3) got some sort of infection along the way.

My bad beer only attenuated 25 points, and was a green apple bomb. I tried to save it with a repitch of champange yeast, but it was to no avail.


Mylo

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