Acetaldehyde flavors post fermentation.

[Ruden]

Made a vermont IPA using white labs london fog. everything was going great during fermentation, smelled great, looks good and when i took a gravity reading it was doing its thing quickly. I had a really thick and heavy layer of krausen after 1.5 weeks and it was not dropping. I called my local homebrew store and they recommended i rock the fermenter lightly.I did so for maybe 5-10 seconds. After I did this is when i wanted to say the flavor changed. I took one last sample before kegging it a few days later, (first time kegging!!) and it was still giving me green apple and almost too much of an alcohol smell.

after typing my story up it seems obvious of where i went wrong but what else could have caused this? Could me constantly checking up on the brew (every 3-5 days) cause oxidation to effect it this bad? I am using a brewing bucket as my fermenter so when the top opens up there is exposure to the air.

thanks for the help in advance guys.

 

[Toxxyc]

What was your gravity before starting, when ending, what was your fermentation temperatures and also what yeast did you use?

 

[divrack]

I'm surprised your lhbs told you to mess with yeast. Yeast are the masters and should not be harassed.
Air is definitely a problem for the style of beer but doesn't taste of green apple skin, however that shouldn't develop after being initially ok as far as I know. Perhaps you got an infection, or perhaps it's just not ready.
Its not easy to say what's wrong with it without knowing all factors, and while I don't think it's a terribly great idea to shake the keg, I used to keg before fermentation was done to avoid oxygen exposure in hoppy stuff without problem.

Possibly you stirred in some of the nasty kreausen ring.

Leave it a bit and try again.

You may also be simply tasting hop particles settling to the bottom. This will go away after a while in the fridge and a pint or two, although this wouldn't manifest as smell.

Most likely though a problem elsewhere in the brew or infection

 

[Northern_Brewer]

+1 to not fiddling with your beer, particularly not a NEIPA.

Whilst acetaldehyde can be the result of oxidation, it can also be down to incomplete or stressed fermentation. I'm equally worried by the "too much of an alcohol smell" which again sounds like a stressed fermentation. What was your temperature control like, how much yeast did you pitch, how did you aerate?

 

[dmtaylor]

This sounds like possible contamination. I'd believe that before I'd believe that acetaldehyde would show up in a fermentation that looked healthy.

 

[Ruden]

+1 to not fiddling with your beer, particularly not a NEIPA.

Whilst acetaldehyde can be the result of oxidation, it can also be down to incomplete or stressed fermentation. I'm equally worried by the "too much of an alcohol smell" which again sounds like a stressed fermentation. What was your temperature control like, how much yeast did you pitch, how did you aerate?

I shook the bucket fermenter for 10 minutes.