How did I get Acetaldehyde again?

Racked to keg today after 21 days in primary. Before racking i was expecting a nice aroma since this IPA was dry hopped with 2 ounces each of simcoe and amarillo. what i got....green apples. WHY!!!! Do I really need to age my beer in primary for longer than 21 days?

some facts-

- I made a healthy starter via mr. malty
- Yeast pitched at 70, temp controlled initial fermentation at 62, raised to 68 by day 11.
- FG was reached at day 11 (maybe prior)
- Cold crashed at day 18 (3 days)
- I dumped a previous batch due to the beer having a possible infection from primary bucket. The beer had similar green apple characteristics, the flavor was tart even 5 weeks in keg, it was dumped. Im not sure if it was an infection or acetaldehyde. I tossed the bucket and got a glass carboy to hopefully eliminate this problem. Sanitation and cleaning was strict this time around. Hydrometer sample tasted fantastic.

Now, only the aroma so far is green apples. Im fearing though i will be tasting tart again in this beer or the aroma from hops will be dominated by green apples. I know Im jumping ahead and not giving it time, but based on the facts Ive presented is there a reason why im getting this green apple in my beer? I remember previous batches before racking smelling awesome when dry hopped heavily. the green apple overpowers the past few batches...

How did you sanitize? You tossed the bucket, but what about the hoses, connectors, etc? The critters could be hiding anywhere from the kettle to the keg.

Starsan spray bottle. The only thing that touches the wort from kettle to carboy is a sanitized funnel that is brand new purchased. I just dump the wort once cooled into the carboy, pitch yeast, and hook up a blow off tube (also brand new).

Is it possible a starter could cause this problem? I make my starters via mr malty 1 day prior to brew day. I keep it in the chest freezer at around 65 and generally swirl it up every few hours.

if it gets worse, you know you have an infection as normally occuring acetaldehyde should only get better with time. Did the last keg get worse over the course of 5 weeks?
I don't see any obvious points of infection so I have no idea other than that it'd be best to identify if this is getting worse or better. Better means you need to condition longer or pitch more yeast, more oxygen, etc.

bruin_ale said:

if it gets worse, you know you have an infection as normally occuring acetaldehyde should only get better with time. Did the last keg get worse over the course of 5 weeks?
I don't see any obvious points of infection so I have no idea other than that it'd be best to identify if this is getting worse or better. Better means you need to condition longer or pitch more yeast, more oxygen, etc.

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im not sure if that batch actually got worse, but at 5 weeks it wasnt getting any better. it was definitely not what i wanted. i had that bucket for 2 years and tossed it for a new glass carboy. im pretty sure there is no infection in this batch (no notable signs anyways). usually leaving it on primary for 21 days seems to be fine, maybe ill leave it for 30 next time. i made a starter, so im sure there was a enough yeast. what about the yeast not having enough oxygen? i was swirling the starter every few hours 24 hours prior to pitching. i dumped my wort through a funnel very aggressively into the carboy which left about 8 inches of foam. i assumed that would be plenty oxygen for the yeast.

For the oxygenation I was just talking to overall yeast health, using MrMalty is great and it sounds like everything you're doing was good. It's just another variable.

How high was the OG on this beer?

bruin_ale said:

For the oxygenation I was just talking to overall yeast health, using MrMalty is great and it sounds like everything you're doing was good. It's just another variable.

How high was the OG on this beer?

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1.070
FG- 1.012 when I checked at 11 days...

Okay, that's not overly high but 3 weeks from brew to keg might be a little on the fast side.

The other thing that can cause green apple flavors is oxidation, but it doesn't sound likely as these are samples straight from primary right?

i always thought acetaldehyde was from stressed yeast? i'm surprised to see infection mentioned in this thread as I don't think that's normally the cause of this off-flavor.

a few things that jump out to me:

1) why are you pitching your yeast at 70 and then letting it get cooled down to 62? i don't know that this would cause it, but it seems like that would stress the yeast out a bit if they're starting to plug along at 70 for 10 hours or so (until it gets cooled down in your chamber) and then get cooled down almost 10 degrees.

edit: sorry, just saw the part about oxygenating. i think that might be part of your problem, i'd look into getting an aquarium stone, or shaking the carboy for a while, or something to try to get more o2 in there.

edit again: IMHO, 21 days should be plenty of time.

Yeah acetaldehyde is not an infection. It is just a characteristic found in most green beer.

It should be gone after you bottle it and wait a month, just like you should.

Acetaldehyde is a normal part of the process, and honestly your schedule sounds pretty rushed for a somewhat "big" beer like an IPA.

If you give the yeast more time to do their thing, the acetaldehyde should subside after a while.

Just so you know, it will show back up again when you consume the beer. When your body metabolizes alcohol, acetaldehyde is one of the by products. It's one of the major causes (along with dehydration) of hangovers, and over the long term is also the part of heavy drinking that can cause liver damage. Your liver doesn't mind alcohol (ethanol), but acetaldehyde pisses it off in large enough quantities.

It's just part of the process. You have to have the patience for the beer to pass through that stage and then it will eventually get where it's supposed to be.

The calendar doesn't matter. The beer is done when it tastes like it's done. And not one day before.

mlg5039 said:

Yeah acetaldehyde is not an infection. It is just a characteristic found in most green beer.

It should be gone after you bottle it and wait a month, just like you should.

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Look up acetic acid bacteria.. That is why some of us are mentioning infection.

android said:

i always thought acetaldehyde was from stressed yeast? i'm surprised to see infection mentioned in this thread as I don't think that's normally the cause of this off-flavor.

a few things that jump out to me:

1) why are you pitching your yeast at 70 and then letting it get cooled down to 62? i don't know that this would cause it, but it seems like that would stress the yeast out a bit if they're starting to plug along at 70 for 10 hours or so (until it gets cooled down in your chamber) and then get cooled down almost 10 degrees.

edit: sorry, just saw the part about oxygenating. i think that might be part of your problem, i'd look into getting an aquarium stone, or shaking the carboy for a while, or something to try to get more o2 in there.

edit again: IMHO, 21 days should be plenty of time.

Click to expand...

i pitch at 70 and immediately put my fermenter in the chest freezer with the temp control probe taped to the side of the carboy at 62. i assume the wort is getting to 62 before the yeast even really starts the fermentation process. why do i start ferment at 62? because the worts temp is higher than that once fermentation starts and im hoping to achieve a cleaner beer w/ less esters. after a few days i raise it to 68. this is correct right? as far as oxygenation, i would think vigorously dumping the wort into the carboy through a funnel and strainer would be plenty? i never had problems in the past...